Best Practices Guidebook for Greenhouse Gas Reductions in Freight ...

Best Practices Guidebook for Greenhouse Gas Reductions in Freight Transportation Final Report Prepared for U.S. Department of Transportation via Center for Transportation and the Environment

Prepared by H. Christopher Frey and Po-Yao Kuo Department of Civil, Construction, and Environmental Engineering North Carolina State University Raleigh, North Carolina 27695-7908 USA

October 4, 2007

ACKNOWLEDGMENTS/ DISCLAIMER This work is supported by the U.S. Department of Transportation via Center for Transportation and the Environment. The authors are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of either the U.S. Department of Transportation or the Center for Transportation and the Environment at the time of publication. This report does not constitute a standard, specification, or regulation.

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TABLE OF CONTENTS EXECUTIVE SUMMARY........................................................................................................ES-1 ES.1 Background ....................................................................................................... ES-1 ES.2 Study Methodology........................................................................................... ES-1 ES.3 Identification of Best Practices and Their Estimated Reductions in GHG Emissions, Energy Use and Refrigerant Use .................................................... ES-4 ES.4 Quantitative Assessment Results .................................................................... ES-10 ES.5 Major Findings................................................................................................ ES-12 ES.6 Recommendations........................................................................................... ES-13 1.0 PURPOSE AND BACKGROUND .....................................................................................1 1.1 Purpose of This Guidebook .................................................................................... 1 1.2 Background ............................................................................................................. 2 1.3 Using This Guidebook ............................................................................................ 4 2.0 DEFINITION OF KEY CONCEPTS ..................................................................................7 2.1 “Best Practices” for Greenhouse Gas Reductions in Freight Transportation ......... 7 2.2 Modes of Freight Transportation ............................................................................ 7 2.3 Subgroup ................................................................................................................. 9 2.4 Responsible Parties ................................................................................................. 9 2.5 Target Parties......................................................................................................... 10 2.6 Greenhouse Gas Emissions ................................................................................. 10 2.7 Strategy Types for Reducing Greenhouse Gas Emissions .................................... 10 2.7.1 Technological Strategies ...............................................................................10 2.7.2 Operational Strategies ...................................................................................10 2.8 Practice Goals ........................................................................................................11 2.9 Developmental Status ............................................................................................11 3.0 METHODOLOGY ............................................................................................................12 3.1 Literature Review.................................................................................................. 12 3.2 Reductions in GHG Emissions, and Energy or Refrigerant Use, for Individual Best Practices ........................................................................................................ 12 3.3 Quantitative Assessments of Best Practices.......................................................... 14 3.3.1. Quantifying Cost Implications...................................................................14 3.3.2 Summarizing and Reporting the Results....................................................15 3.4 Qualitative Assessments of Best Practices............................................................ 18 3.5 Aggregated Reductions in GHG Emissions, Energy or Refrigerant Use for Multiple Best Practices ......................................................................................... 18 ii

4.0.

3.6 Intermodal Substitution......................................................................................... 22 BEST PRACTICES FOR THE TRUCK MODE ..............................................................23 4.1 Anti-Idling............................................................................................................. 23 4.1.1 Best Practice 1-1: Off-Board Truck Stop Electrification.........................24 4.1.2 Best Practice 1-2: Truck-Board Truck Stop Electrification.....................24 4.1.3 Best Practice 1-3: Auxiliary Power Units................................................24 4.1.4 Best Practice 1-4: Direct-Fired Heaters...................................................25 4.1.5 Best Practice 1-5: Direct-Fired Heaters with Thermal Storage Units...........................................................................................................25 4.2 Air Conditioning System Improvement................................................................ 26 4.2.1 Best Practice 1-6: Enhanced Air Conditioning System I - for Direct Emissions ........................................................................................26 4.2.2 Best Practice 1-7: Enhanced Air Conditioning System II - for Indirect Emissions......................................................................................26 4.2.3 Best Practice 1-8: Alternative Refrigerants - CO2 ...................................26

4.3

4.4

4.5 4.6

4.2.4 Best Practice 1-9: Alternative Refrigerants - HFC-152a.........................27 4.2.5 Best Practice 1-10: Alternative Refrigerants - HC ..................................27 Aerodynamic Drag Reduction .............................................................................. 27 4.3.1 Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares ...........................................28 4.3.2 Best Practice 1-12: Vehicle Profile Improvement II - Closing and Covering of Gap between Cab and Trailer or Van, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers..........................28 4.3.3 Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures ......................................................28 4.3.4 Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction ................28 4.3.5 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer .............29 4.3.6 Best Practice 1-16: Vehicle Load Profile Improvement ..........................29 Tire Rolling Resistance Improvement .................................................................. 29 4.4.1 Best Practice 1-17: Automatic Tire Inflation Systems ............................30 4.4.2 Best Practice 1-18: Wide-Base Tires .......................................................30 4.4.3 Best Practice 1-19: Low-Rolling-Resistance Tires..................................30 4.4.4 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling Resistance ..................................................................................................31 Hybrid Propulsion ― Best Practice 1-21: Hybrid trucks ................................... 31 Weight Reduction ― Best Practice 1-22: Lightweight Materials ...................... 31 iii

4.7

5.0.

6.0.

Transmission Improvement................................................................................... 32 4.7.1 Best Practice 1-23: Advanced Transmission ...........................................32 4.7.2 Best Practice 1-24: Transmission Friction Reduction through Low-Viscosity Transmission Lubricants....................................................33 4.8 Diesel Engine Improvement ................................................................................. 33 4.8.1 Best Practice 1-25: Engine Friction Reduction through Low-Viscosity Engine Lubricants..............................................................33 4.8.2 Best Practice 1-26: Increased Peak Cylinder Pressures...........................33 4.8.3 Best Practice 1-27: Improved Fuel Injectors ...........................................34 4.8.4 Best Practice 1-28: Turbocharged, Direct Injection to Improved Thermal Management................................................................34 4.8.5 Best Practice 1-29: Using Thermoelectric Technology to Recovery Waste Heat .................................................................................34 4.9 Accessory Load Reduction ................................................................................... 35 4.9.1 Best Practice 1-30: Electric Auxiliaries...................................................35 4.9.2 Best Practice 1-31: Fuel-Cell-Operated Auxiliaries ................................35 4.10 Modifications in Driver Operational Practice ―Best Practice 1-32: Truck Driver Training Program....................................................................................... 36 4.11 Alternative Fuel ―Best Practice 1-33: B20 Biodiesel Fuel............................... 36 4.12 Summary of Potential Best Practices for the Truck Mode.................................... 37 4.13 Comparisons of Modal GHG Emissions Reductions for the Best Practices ........ 37 4.14 Quantitative Cost Results for Selected Best Practices.......................................... 50 BEST PRACTICES FOR THE RAIL MODE...................................................................52 5.1 Anti-Idling............................................................................................................. 52 5.1.1 Best Practice 2-1: Combined Diesel Powered Heating and Auto Engine Start/Stop Systems ................................................................52 5.1.2 Best Practice 2-2: Battery-Diesel Hybrid Switching Locomotive...........53 5.1.3 Best Practice 2-3: Plug-In Units ..............................................................53 5.2 Weight Reduction ― Best Practice 2-4: Lightweight Materials ........................ 53 5.3 Rolling Resistance Improvement ― Best Practice 2-5: Lubrication Improvement ......................................................................................................... 54 5.4 Alternative Fuel ― Best Practice 2-6: B20 Biodiesel Fuel for Locomotives .... 54 5.5 Summary of Potential Best Practices for the Rail Mode ...................................... 54 5.6 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 54 5.7 Quantitative Cost Results for the Selected Best Practices .................................... 58 BEST PRACTICES FOR THE AIR MODE .....................................................................60 iv

6.1

7.0

8.0

Aerodynamic Drag Reduction .............................................................................. 61 6.1.1 Best Practice 3-1: Surface Grooves .........................................................61 6.1.2 Best Practice 3-2: Hybrid Laminar Flow Technology .............................61 6.1.3 Best Practice 3-3: Blended Winglet.........................................................62 6.1.4 Best Practice 3-4: Spiroid Tip..................................................................62 6.2 Air Traffic Management ― Best Practice 3-5 ...................................................... 62 6.3 Weight Reduction.................................................................................................. 64 6.3.1 Best Practice 3-6: Airframe Weight Reduction .......................................64 6.3.2 Best Practice 3-7: Non-Essential Weight Reduction ...............................64 6.4 Ground Support Equipment Improvement............................................................ 65 6.4.1 Best Practice 3-8: Ground-Based Equipment as an Alternative to Auxiliary Power Units ...........................................................................65 6.4.2 Best Practice 3-9: Electric or Hybrid Heavy Duty Delivery Trucks .......65 6.5 Engine Improvement ― Best Practice 3-10: Improved Engine Overall Efficiency.............................................................................................................. 65 6.6 Summary of Potential Best Practices for the Air Mode........................................ 66 6.7 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 66 BEST PRACTICES FOR THE WATER MODE...............................................................72 7.1 Propeller System Improvement............................................................................. 72 7.1.1 Best Practice 4-1: Off-Center Propeller...................................................72 7.1.2 Best Practice 4-2: Propeller Boss Cap with Fins (PBCF)........................73 7.1.3 Best Practice 4-3: Auxiliary Free-Rotating Propulsion Device behind the Main Propeller..........................................................................73 7.2 Anti-Idling ― Best Practice 4-4: Shoreside Power for Marine Vessels at Ports .................................................................................................................. 73 7.3 Alternative Fuel ―Best Practice 4-5: B20 Biodiesel Fuel for Ships ................. 74 7.4 Summary of Potential Best Practices for the Water Mode.................................... 75 7.6 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 75 7.7 Quantitative Cost Results for the Water Mode ..................................................... 75 BEST PRACTICES FOR THE PIPELINE MODE...........................................................82 8.1 Process Control Device Improvement .................................................................. 82 8.1.1 Best Practice 5-1: Convert Natural Gas Pneumatic Controls to Instrument Air ............................................................................................82 8.1.2 Best Practice 5-2: Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices............................................83 8.2 Connecting Method ―Best Practice 5-3: “Hot Tap” Pipeline Connecting v

Method .................................................................................................................. 83 8.3 Maintenance.......................................................................................................... 83 8.3.1 Best Practice 5-4: Transfer Compression ................................................83 8.3.2 Best Practice 5-5: Inline Inspection.........................................................83 8.4 Summary of Potential Best Practices for the Pipeline Mode................................ 84 8.5 Comparisons of the Modal GHG Emissions Reductions for the Best Practices... 84 8.6 Quantitative Cost Results for the Pipeline Mode.................................................. 84 9.0 SUMMARY AND COMPARISON OF GHG EMISSIONS REDUCTIONS FOR ALL FREIGHT TRANSPORTATION MODES.......................................................89 9.1 Truck Mode........................................................................................................... 89 9.2 Rail Mode.............................................................................................................. 92 9.3 Air Mode............................................................................................................... 97 9.4 Water Mode........................................................................................................... 97 9.5 Pipeline Mode ..................................................................................................... 101 9.6 Intermodal Comparisons..................................................................................... 101 9.6.1 Total Modal GHG Emissions Reductions................................................101 9.6.2 Comparisons of Best Practices Whose Costs Are Assessed Quantitatively...........................................................................................105 9.6.3 Intermodal Substitutions ..........................................................................107 10.0. CONCLUSIONS AND RECOMMENDATIONS...........................................................110 10.1 Conclusions..........................................................................................................110 10.2 Recommendations for Future Research Needs ....................................................111 REFERENCES …….………………………………………………………………………….……… 113 APPENDIX A. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR TRUCK MODE BEST PRACTICES ..........................135 Appendix A.1 Best Practice 1-1: Off-Board Truck Stop Electrification ................... 135 Appendix A.2 Best Practice 1-2: Truck-Board Truck Stop Electrification ............... 142 Appendix A.3 Best Practice 1-3: Auxiliary Power Units .......................................... 143 Appendix A.4 Best Practice 1-4: Direct-Fired Heaters ............................................. 148 Appendix A.5 Best Practice 1-5: Direct-fired Heaters with Thermal Storage Units....................................................................................................... 153 Appendix A.6 Best Practice 1-6: Enhanced Air Conditioning System I - for Direct Emissions ................................................................................................. 154 Appendix A.7 Best Practice 1-7: Enhanced Air Conditioning System II - for Indirect Emissions............................................................................................... 155 Appendix A.8 Best Practice 1-8: Alternative Refrigerants - CO2 ............................. 156 vi

Appendix A.9 Best Practice 1-9: Alternative Refrigerants - HFC-152a ................... 157 Appendix A.10 Best Practice 1-10: Alternative Refrigerants - HC........................... 158 Appendix A.11 Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares .................................................... 159 Appendix A.12 Best Practice 1-12: Vehicle Profile Improvement II - Closing and Covering of Gap between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers.................................................. 160 Appendix A.13 Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures ........................................................ 161 Appendix A.14 Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction......... 162 Appendix A.15 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer...... 163 Appendix A.16 Best Practice 1-16: Vehicle Load Profile Improvement................... 164 Appendix A.17 Best Practice 1-17: Automatic Tire Inflation Systems ..................... 165 Appendix A.18 Best Practice 1-18: Wide-Base Tires................................................ 166 Appendix A.19 Best Practice 1-19: Low-Rolling-Resistance Tires .......................... 167 Appendix A.20 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling Resistance ........................................................................................................... 168 Appendix A.21 Best Practice 1-21: Hybrid Trucks ................................................... 169 Appendix A.22 Best Practice 1-22: Lightweight Materials....................................... 175 Appendix A.23 Best Practice 1-23: Advanced Transmission.................................... 176 Appendix A.24 Best Practice 1-24: Transmission Friction Reduction through Low-Viscosity Transmission Lubricants............................................................. 177 Appendix A.25 Best Practice 1-25: Engine Friction Reduction through Low-Viscosity Engine Lubricants....................................................................... 178 Appendix A.26 Best Practice 1-26: Increased Peak Cylinder Pressures ................... 179 Appendix A.27 Best Practice 1-27: Improved Fuel Injectors.................................... 180 Appendix A.28 Best Practice 1-28: Turbocharged, Direct Injection to Improved Thermal Management ......................................................................................... 181 Appendix A.29 Best Practice 1-29: Thermoelectric Technology to Recovery Waste Heat .......................................................................................................... 182 Appendix A.30 Best Practice 1-30: Electric Auxiliaries ........................................... 183 Appendix A.31 Best Practice 1-31: Fuel-Cell-Operated Auxiliaries......................... 184 Appendix A.32 Best Practice 1-32: Truck Driver Training Program ........................ 185 Appendix A.33 Best Practice 1-33: B20 Biodiesel Fuel for Trucks .......................... 186 APPENDIX B. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR RAIL MODE BEST PRACTICES...............................191 vii

Appendix B.1 Best Practice 2-1: Combined Diesel Powered Heating System and Auto Engine Start/Stop System .................................................................... 191 Appendix B.2 Best Practice 2-2: Battery-Diesel Hybrid Switching Locomotive ..... 197 Appendix B.3 Best Practice 2-3: Plug-in Unit........................................................... 203 Appendix B.4 Best Practice 2-4: Light Weight Materials ......................................... 210 Appendix B.5 Best Practice 2-5: Lubrication Improvement ......................................211 Appendix B.6 Best Practice 2-6: B20 Biodiesel Fuel for Locomotives .................... 212 APPENDIX C. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR AIR MODE BEST PRACTICES .................................217 Appendix C.1 Best Practice 3-1: Surface Grooves.................................................... 217 Appendix C.2 Best Practice 3-2: Hybrid Laminar Flow Technology........................ 218 Appendix C.3 Best Practice 3-3: Blended Winglet ................................................... 219 Appendix C.4 Best Practice 3-4: Spiroid Tip ............................................................ 220 Appendix C.5 Best Practice 3-5: Air Traffic Management Improvement................. 221 Appendix C.6 Best Practice 3-6: Airframe Weight Reduction.................................. 222 Appendix C.7 Best Practice 3-7: Non-Essential Weight Reduction.......................... 223 Appendix C.8 Best Practice 3-8: Ground-Based Equipment as an Alternative to Auxiliary Power Units ........................................................................................ 224 Appendix C.9 Best Practice 3-9: Electric or Hybrid Heavy Duty Delivery Trucks 225 Appendix C.10 Best Practice 3-10: Improved Engine Overall Efficiency ................ 226 APPENDIX D. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR WATER MODE BEST PRACTICES ..........................227 Appendix D.1 Best Practice 4-1: Off-Center Propeller ............................................. 227 Appendix D.2 Best Practice 4-2: Propeller Boss Cap with Fins ............................... 228 Appendix D.3 Best Practice 4-3: Auxiliary Free-rotating Propulsion Device behind the Main Propellers ................................................................................. 229 Appendix D.4 Best Practice 4-4: Shoreside Power for Marine Vessels at Ports ....... 230 Appendix D.5 Best Practice 4-5: B20 Biodiesel Fuel for Ships................................ 231 APPENDIX E. DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR PIPELINE MODE BEST PRACTICES ......................239 Appendix E.1 Best Practice 5-1: Convert Natural Gas Pneumatic Controls to Instrument Air ..................................................................................................... 239 Appendix E.2 Best Practice 5-2: Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices..................................................... 247 Appendix E.3 Best Practice 5-3: “Hot Tap” Method................................................. 252 viii

Appendix E.4 Best Practice 5-4: Transfer Compression ........................................... 257 Appendix E.5 Best Practice 5-5: Inline Inspection.................................................... 258 APPENDIX F. FUEL PROPERTIES, CO2 EMISSIONS COEFFICIENTS FOR FULES, AND AVERAGE UNIT FUEL COSTS FOR GUIDEBOOK ...........................259 APPENDIX F.1 Properties of Different Fuels ............................................................. 259 F.1.1 Definitions of Fuel Properties..................................................................259 F.1.2 Diesel Fuel ...............................................................................................260 F.1.3 Jet Fuel .....................................................................................................262 F.1.4 Biodiesel ..................................................................................................263 F.1.5 Residual Fuel Oil .....................................................................................263 F.1.6 Natural Gas ..............................................................................................264 APPENDIX F.2 CO2 Emissions Coefficients for Different Fuels ............................... 264 F.2.1 Diesel Fuel ...............................................................................................265 F.2.2 Jet Fuel .....................................................................................................265 F.2.3 Biodiesel ..................................................................................................265 F.2.4 Residual Fuel Oil .....................................................................................265 F.2.5 Natural Gas ..............................................................................................265 F.2.6 Comparison of CO2 Emissions Coefficients of Different Fuels ..............266 APPENDIX F.3 Average Unit Costs for Different Fuels............................................. 266 F.3.1 Diesel Fuel ...............................................................................................266 F.3.2 Jet Fuel .....................................................................................................266 F.3.3 Biodiesel ..................................................................................................266 F.3.4 Residual Fuel Oil .....................................................................................267 F.3.5 Natural Gas ..............................................................................................267 F.3.6 Comparison of Average Unit Cost of Different Fuels..............................267

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LIST OF TABLES Table ES- 1. Table ES- 2.

Table 1- 1. Table 1- 2. Table 2- 1. Table 3- 1. Table 3- 2. Table 3- 3. Table 3- 4. Table 4- 1. Table 4- 2. Table 5- 1. Table 5- 2. Table 6- 1. Table 7- 1. Table 7- 2. Table 8- 1. Table 8- 2. Table 9- 1. Table 9- 2. Table 9- 3. Table 9- 4.

Potential Best Practices and Their Potential Reductions in Modal GHG Emissions and Energy Use................................................................................ ES-5 Summary of Potential GHG Emissions Reductions, Energy Use Reduction, Net Savings, Unit Net Savings, and Simple Pay-back Periods of Selected Best Practices .................................................................................................. ES-11 Greenhouse Gas Emissions from the Freight Transportation Sector in 2003......... 3 A Scenario of GHG Emissions from Freight Transportation from 2003 to 2025......................................................................................................................... 4 Truck Classifications by Weight, Number of Axles, and Number of Tires ............ 9 Contribution of Selected Greenhouse Gases to Total Modes ……………………. 13 The Format of Standardized Reporting Table....................................................... 16 A Standardized List of Responsible Parties and Target Parties ............................ 19 The Format of Simplified Summary Table ........................................................... 21 List and Description of Potential Best Practices for the Truck Mode................... 38 Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Truck Mode ......................................................... 51 List and Description of Potential Best Practices for the Rail Mode ..................... 55 Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Rail Mode............................................................ 59 List and Description of Potential Best Practices for the Air Mode....................... 67 List and Description of Potential Best Practices for the Water Mode .................. 76 Summary Table for the Comparison of the Quantitative Cost Results for A Selected Best Practices for the Water Mode ......................................................... 81 List and Description of Potential Best Practices for the Pipeline Mode............... 85 Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Pipeline Mode ..................................................... 88 Potential Best Practices for the Truck Mode and the Estimated Reductions in GHG Emissions and Energy Use...................................................................... 93 Potential Best Practices for the Rail Mode and the Estimated Reductions in GHG Emissions and Energy Use...................................................................... 96 Potential Best Practices for the Air Mode and the Estimated Reductions in GHG Emissions and Energy Use .......................................................................... 98 Potential Best Practices for the Water Mode and the Estimated Reductions in GHG Emissions and Energy Use.................................................................... 100 x

Table 9- 5. Table 9- 6.

Potential Best Practices for the Pipeline Mode and the Estimated Reductions in GHG Emissions and Energy Use................................................. 102 Quantitative Summary of Reductions in GHG Emissions, Energy Use, and Costs of Selected Best Practices ........................................................................ 106

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LIST OF FIGURES Figure 1- 1 Figure 4- 1.

Overview of the Organization and Content of This Guidebook. .............................5 Reductions in Modal GHG Emissions for the Best Practices for the Truck Mode ......................................................................................................................49 Figure 5- 1. Reductions in Modal GHG Emissions for the Best Practices for the Rail Mode ..57 Figure 6- 1. Reductions in Modal GHG Emissions for the Best Practices for the Air Mode .....71 Figure 7- 1. Reductions in Modal GHG Emissions for the Best Practices for the Water Mode ......................................................................................................................80 Figure 8- 1. Reductions in Modal GHG Emissions for Best Practices for the Pipeline Mode..87 Figure 9- 1. Total Modal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Multiple Best Practices in Each Mode ..................................104 Figure 9- 2. Magnitudes of the Total Modal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Multiple Best Practices for Each Mode..........105 Figure 9- 3. Estimated GHG Emissions per Unit of Freight Transport of Each Mode ...........108

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EXECUTIVE SUMMARY ES.1

Background

Freight transportation is comprised of five major modes: truck, rail, air, water, and pipeline. Freight transportation accounts for approximately 9% of total greenhouse gas (GHG) emissions in the United States.1-3 The individual contributions of each of the five freight transportation modes to total freight transportation GHG emissions are 60, 6, 5, 13, and 16 percent, respectively. Energy use for all modes could increase by 75% from 2003 to 2030, based on a long-term energy trend scenario in the Energy Information Administration’s Annual Energy Outlook 2006.4 Since energy use for freight transportation is expected to increase significantly in the next 25 years, and because GHG emissions are largely based on energy use, GHG emissions will also increase significantly. Governments and the freight industry recognize the need for solutions to meet future challenges for GHG emissions reductions.2,5 There are a growing number of technological and operational strategies, existing or developing, that could reduce GHG emissions. Disseminating information regarding these technological and operational strategies can facilitate decision making to achieve reductions in energy use and GHG emissions. This guidebook presents a survey of potential best practices for reducing energy use and GHG emissions in freight transportation. The report characterizes each potential best practice in order to serve the information needs of decision makers and responsible parties. ES.2

Study Methodology

The methodology includes reviewing literature to identify best practices, assessing maximum reductions in GHG emissions and energy or refrigerant use for individual best practices and of multiple best practices, assessing cost savings, and summarizing and reporting assessment results. The GHG emissions of interest here are CO2, methane (CH4), and refrigerants. CO2 has a global warming potential (GWP) of 1. Methane has a global warming potential of 21. The currently widely used refrigerant, HFC-134a, has a GWP of 1,300. However, methane and refrigerant are emitted in smaller mass amounts than CO2. A potential best practice is an existing or developing strategy or technology that is expected to lead to reductions in energy use, refrigerant use, and greenhouse gas emissions. Potential best practices are identified based on literature review. The potential best practices are categorized by subgroups based on the factors that the practices can improve, or the technologies that vehicles or devices may apply, to reduce GHG emissions. ES-1

The potential reduction in GHG emission and energy or refrigerant use for each potential best practice is estimated based on what may be achievable by 2025. Reductions are compared to estimated 2025 GHG emissions if none of these best practices are adopted. While the scope of this work includes estimate of GHG emissions, energy use, and refrigerant use, in most cases, significant reductions in GHG emissions achievable with potential best practices are associated with reductions in energy use. . The potential per-device reductions in GHG emissions, energy or refrigerant use for an individual potential best practice are estimated based on the results of literature review. Per-device reductions for each potential best practice, except for alternative fuel strategies, are estimated based on the differences in per-device emissions, energy use or refrigerant use with and without the use of this potential best practice. Reductions for alternative fuel strategies are estimated based on life cycle inventories. Each practice may only be applicable to a fraction of all devices within a mode. Identified potential best practices are categorized with respect to developmental status: commercially available, pilot tests, and new concepts. Commercially available systems can be purchased or implemented now. Potential best practices based on pilot tests may be available within five to ten years, whereas those that are new concepts may require research, development, and demonstration that could vary in duration. An assumption is made that each potential best practice reaches a best estimate of maximum market penetration by 2025. Technical, practical, and cost barriers are not quantified here. Actual market penetration may be lower than estimated. However, the estimates provide a useful upper bound as to what might be achieved if adoption of such practices is encouraged. Potential best practices are grouped by subgroup. Subgroups are based on similar objectives or methods. An example is aerodynamic drag reduction. Aggregate reductions in modal GHG emissions and energy or refrigerant use for a subgroup are estimated based on a simple linear combination of the reductions for multiple potential best practices within the subgroup, except in some situations. In some cases, two or more practices within a subgroup are mutually exclusive because they cannot be used simultaneously. In the case of mutual exclusion, the practice with the highest estimated reduction is used in the estimate of total reductions for the subgroup. For example, three alternative refrigerants for air conditioning systems that could be used as potential best practices are mutually exclusive. Only one refrigerant can be used in an air conditioning system. CO2 is chosen here because it has the lowest GWP compared to the other candidate refrigerants and its potential reductions in modal GHG emissions are the highest. Thus, the estimates do not double count mutually exclusive practices. For some potential best practices, it is possible that they could be implemented ES-2

simultaneously but that they may interact. Thus, the total reduction may not be a simple linear combination of the reductions of each practice. An example would be several practices that reduce aerodynamic drag of a truck. However, there is a lack of data upon which to quantify the overall reduction associated with interactions among multiple practices within a subgroup. Therefore, these interactive effects are not quantified. The linear combination may tend to overestimate the maximum possible reduction for the subgroup. Such situations are noted. For all potential best practices, a quantitative estimate is made of the potential reductions in energy use, GHG emissions, and refrigerant leakage. However, for many potential best practices, inadequate data are available for assessment of cost. Quantitative assessments for cost effectiveness are performed, where sufficient data are available for: practice cost; energy or refrigerant cost reduction; and total net cost savings. Total net cost savings is the difference between annual energy or refrigerant cost savings and the annualized costs, the latter of which include levelized capital costs and annual operation and maintenance costs. Net savings per unit of GHG emissions reductions are estimated by normalizing total net savings with respect to GHG emissions reductions. A positive value of net savings means that the practice will pay for itself over some period of time, whereas a negative value means that the annualized costs exceed savings associated with reductions in energy use or refrigerant use. A standardized reporting table, which includes three parts, is used to report the quantitative characteristics and assessment results of individual potential best practices. The first part summarizes characteristics, including: practice name; applicable mode type; subgroup; responsible parties; target parties; targeted GHGs; strategy type; practice goals; developmental status; and practice summary The second part includes: the magnitude of transport activity for the whole mode; the magnitude of transport activity to which the practice is applicable; total annual modal reductions in GHG emissions, energy use, and refrigerant use; and reductions of each per unit of freight transport. The third part includes: annualized costs; energy or refrigerant costs savings; net savings per unit of reductions in GHG emissions and energy or refrigerant use; and simple payback periods. The effects of the potential best practices where cost quantitative data are not available are discussed qualitatively in a structured approach. A simplified summary table, which includes four parts, is used to report the qualitative assessment results. The first part is technological information, including: practice name; applicable mode type; subgroup; responsible parties; target parties; target GHGs of interest; strategy type; practice goals for GHG emissions reduction; developmental status; and a brief summary of the practice. The second part includes quantitative estimates of the potential modal reductions in GHG emissions, energy use or refrigerant use for individual potential best practices. The third part is cost information, which can be any available knowledge, such as assumptions regarding capital cost, cost ES-3

premiums or cost savings, and retail price impacts reported in the literature. describes the benefits and the drawbacks of the practice. ES.3

The fourth part

Identification of Potential Best Practices and Their Estimated Reductions in GHG Emissions, Energy Use and Refrigerant Use

A total of 59 strategies have been identified as potential best practices in freight transportation. There are 33, 6, 10, 5, and 5 potential best practices for the truck, rail, air, water, and pipeline modes, respectively. Over half of the total number of potential best practices is for the truck mode. Reduction in energy use is the basis of GHG emissions reductions for 51 of the potential best practices. One practice can reduce direct GHG emissions but increases direct energy use. For 3 practices, life cycle GHG emissions are reduced but life cycle energy use may be increased. Four strategies, which are potential best practices for the air conditioning system improvement subgroup for the truck mode, can reduce GHG emissions by reducing refrigerant leakage rate or by using low global-warming-potential refrigerants. Table ES-1 summarizes key aspects of the characteristics and potential reductions in modal GHG emissions and energy use for individual potential best practices. The magnitude of aggregate reductions in 2025 for each subgroup is also summarized in Table ES-1. The reported reductions are the difference between 2025 GHG emissions (or energy use) with and without use of potential best practices in a subgroup. For cases of mutual exclusivity within a subgroup, one estimate of the reductions is given. For cases of multiple practice interaction, a simple linear combination of the reductions is applied, which may tend to overestimate the maximum possible reduction for the subgroup. The potential total GHG emissions reduction by 2025 for all 59 potential best practices is estimated as 4.6×108 tons CO2 eq. If no potential best practices are implemented, the total GHG emissions by 2025 for the freight transportation are estimated to be 11.0×108 tons CO2 eq. If all potential best practices are implemented, the total GHG emissions for the freight transportation are estimated to be 6.4×108 tons CO2 eq. Thus, total estimated GHG emissions reductions by 2025 for all potential best practices, 4.6×108 tons CO2 eq., is estimated to be 42% of 2025 GHG emissions if no potential best practice is implemented. Most of these estimated reductions (4.4×108 tons CO2 eq. out of a total reduction of 4.6×108 tons CO2 eq.) are attributed to an estimated energy use reduction of 4.5×1015 BTU. A small portion of these estimated reductions (0.18×108 tons CO2 eq.) is attributed to refrigerant leakage rate reduction or use of low global-warming-potential refrigerants.

ES-4

1-1 1-2 Anti-Idling (E)

1-3 1-4

Truck

1-5 1-6 Air Conditioning System Improvement (B)

1-7 1-8 1-9 1-10

Off-Board Truck Stop Electrification Truck-Board Truck Stop Electrification Auxiliary Power Units Direct-Fired Heaters Direct-Fired Heaters with Thermal Storage Units Enhanced Air Conditioning System I - for Direct Emissions Enhanced Air Conditioning System II - for Indirect Emissions Alternative Refrigerants - CO2 Alternative Refrigerants HFC-152a Alternative Refrigerants - HC

C

L

L

C

L

L

C C

M M

M M

P

M

M

P

L

-

C

L

L

N

M

-

N

M

-

N

M

-

The Magnitude of Aggregate GHG Emissions Reductions in 2025 for Each Subgroup (106 Tons CO2 eq.)e The Magnitude of Aggregate Energy Use Reduction in 2025 for Each Subgroup (1015 BTU)f

Brief Name of Potential Best Practice

Potential Reduction in Modal Energy Used

I.D. No.

Potential Reduction in Modal GHG Emissionsc

Subgroupa

Developmental Statusb

Mode

Table ES- 1. Potential Best Practices and Their Potential Reductions in Modal GHG Emissions and Energy Use

15.0

0.19

19.2g

0.02

Continued on next page a

b

c

d

e

f g

Some best practices within a subgroup are mutually exclusive or have interactions. (E) = mutually exclusive within a subgroup; (I) = interaction within a subgroup; and (B) = some best practices are mutually exclusive and some have interactions within a subgroup. Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now. Potential reductions in modal GHG emissions are estimated based on the difference in 2025 modal emissions with and without the selected best practice divided by the total modal emissions if no best practices are implemented. These potential reductions are categorized into three ranges: low (L) (0% - 1%), medium (M) (1% - 4%), and high (H) (> 4%). Potential reductions in modal energy use are estimated based on the difference in 2025 modal energy use with and without the selected best practice divided by the total modal energy use if no best practices are implemented. These potential reductions are categorized into four ranges: low (L) (0% - 1%), medium (M) (1% - 4%), high (H) (> 4%), and negative (NG) (energy increases). “-” refers to no reduction. These reductions are estimated based on the difference between 2025 modal emissions with and without implementation of the representative best practices of the subgroup. As noted in the text, only one best practice is selected if multiple practices within a subgroup are mutually exclusive. For cases of multiple interactions, a simple linear combination of the reductions is applied. These reductions are estimated based on the difference between 2025 modal energy use with and without implementation of the representative best practices of the subgroup. Of the reported value, 17.8×106 tons CO2 eq. aggregated GHG emission reduction is attributed to refrigerant leakage rate reduction or use of low global-warming-potential refrigerants.

ES-5


C

M

M

C

M

M

C

M

M

N

M

M

N

M

M

C

L

L

C C C

L M M

L M M

N

L

L

N P P

M H L

M H L

C

L

L

C

M

M

C

M

M

P

H

H

C

L

L

N

H

H

C N

M H

1-32 Truck Driver Training Program

C

1-33 B20 Biodiesel Fuel for Trucks

C

I.D. Brief Name of Potential Best No. Practice

1-11

1-12 Aerodynamic Drag Reduction (B)

1-13 1-14

Truck

1-15 1-16 Tire Rolling Resistance Improvement (E) Hybrid Propulsion Weight Reduction Transmission Improvement (I)

1-17 1-18 1-19 1-20 1-21 1-22 1-23 1-24 1-25

Truck

Diesel Engine Improvement (I)

1-26 1-27 1-28 1-29

Accessory Load Reduction (B) Driver Operation Improvement Alternative Fuel Total for the Truck Mode

1-30 1-31

Cab Top Deflector, Sloping Hood and Cab Side Flares Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Trailer Leading and Trailing Edge Curvatures Pneumatic Aerodynamic Drag Reduction Planar Boat Tail Plates on a Tractor-Trailer Vehicle Load Profile Improvement Automatic Tire Inflation Systems Wide-base Tires Low-Rolling-Resistance Tires Pneumatic Blowing to Reducing Rolling Resistance Hybrid trucks Lightweight Materials Advanced Transmission Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Engine Friction Reduction through Low-Viscosity Engine Lubricants Increased Peak Cylinder Pressures Improved Fuel Injectors Turbocharged, Direct Injection to Improved Thermal Management Thermoelectric Technology to Recovery Waste Heat Electric Auxiliaries Fuel-Cell-Operated Auxiliaries

Continued on next page

ES-6



Subgroupa


Mode

Table ES-1. Continued

66.6

0.83

28.3

0.35

24.5 33.3

0.30 0.41

13.6

0.17

118.3

1.47

M H

39.6

0.49

M

M

22.3

0.28

H

NG

30.8

-0.37

411.5

4.14

Weight Reduction Rolling Resistance Improvement Alternative Fuel

Combined Diesel Powered 2-1 Heating System and Auto Engine Start/stop System Battery-Diesel Hybrid Switching 2-2 Locomotive 2-3 Plug-In Units 2-4 Light Weight Materials 2-5 Lubrication Improvement 2-6

B20 Biodiesel Fuel for Locomotives

P

M

M

C

M

M

C C

L H

P N

3.4

0.04

L H

3.0

0.04

M

M

2.6

0.03

H

NG

3.5

-0.04

12.6

0.07

5.7

0.06

Water

Air

Total for the Rail Mode 3-1 Surface Grooves Hybrid Laminar Flow Aerodynamic Drag 3-2 Technology Reduction (E) 3-3 Blended Winglet 3-4 Spiroid Tip Air Traffic Air traffic Management 3-5 Management Improvement 3-6 Airframe Weight Reduction Weight Reduction 3-7 Non-Essential Weight Reduction Ground-Based Equipment as an Ground Support 3-8 Alternative to Auxiliary Power Equipment Units Improvement Electric or Hybrid Heavy Duty 3-9 Delivery Trucks Improved Engine Overall Engine Improvement 3-10 Efficiency Total for the Air Mode 4-1 Off-Center Propeller 4-2 Propeller Boss Cap with Fins Propeller System Auxiliary Free-Rotating Improvement (E) 4-3 Propulsion Device behind the Main Propeller Shoreside Power for Marine Anti-Idling 4-4 Vessels at Ports Alternative Fuel 4-5 B20 Biodiesel Fuel for Ships Total for the Water Mode


ES-7



Rail

Anti-Idling (E)



Subgroupa


Mode


P

M

M

N

H

H

C P

M M

M M

N

H

H

3.5

0.04

N N

M L

M L

1.8

0.02

M

M

1.7

0.02

H

H

7.7

0.08

20.4

0.21

3.7

0.04

P P C

C C

M M

M M

C

M

M

P

L

NG

0.2

> -0.01

N

M

NG

1.5

-0.02

5.3

0.03

Convert Natural Gas Pneumatic Controls to Instrument Air Replace High-Bleed Natural Gas 5-2 Pneumatic Devices with Low-Bleed Pneumatic Devices

Pipeline

5-1 Process Control Device Improvement Connecting Method Maintenance

5-3 “Hot Tap” Method 5-4 Transfer Compression 5-5 Inline Inspection

Total for the Pipeline Mode

ES-8

C

L

L

C

L

L

C C C

M L M

L L L





Subgroupa


Mode


1.4

< 0.01

2.5

< 0.01

1.8

< 0.01

5.7

0.01

Within each mode, multiple potential best practices can be applied simultaneously to achieve total 2025 modal GHG emissions reductions (compared to projected emissions if no potential best practices are used) of 57, 19, 34, 4, and 4 percent for the truck, rail, air, water, and pipeline modes, respectively. In making these estimates, we do not double count mutually exclusive potential best practices and we consider linear combinations of reductions for multiple potential best practices that could synergistically interact. The potential best practices also vary substantially in terms of their potential percentage reductions in modal GHG emissions. The variations in reductions among individual practices range from 0.2 to 5.5 percent for the truck mode, 0.6 to 5.5 percent for the rail mode, 1.0 to 13.0 percent for the air mode, 0.2 to 3.0 percent for the water mode, and 0.1 to 1.9 percent for the pipeline mode. The average reductions for a potential best practice are 2.2, 3.4, 2.3, 1.6 and 1.3 percent for the truck, rail, air, water, and pipeline modes, respectively. There is also substantial variability among the potential best practices in terms of their contributions to percentage decreases or increases in modal energy use. The range of these changes among individual potential best practices are from a 4.3 percent increase to a 5.7 percent decrease for the truck mode, a 5.3 percent increase to a 4.8 percent decrease for the rail mode, a 1.0 to 13.0 percent decrease for the air mode, a 1.3 percent increase to a 3.0 percent decrease for the water mode, and a 0.02 to 0.5 percent decrease for the pipeline mode. The averages of these changes are 1.8, 1.5, 2.3, 1.0, and 0.2 percent for the truck, rail, air, water, and pipeline modes, respectively. Several potential best practices in the truck, rail, and water modes are based on alternative fuels. Alternative fuel strategies consume more energy than conventional petroleum fuel, based on life cycle inventories. Thus, the average percentage reductions in modal energy use among all potential best practices for truck, rail and water, which range from 1.0 to 1.8 percent, are significantly smaller than their average percentage reductions in modal GHG emissions, which range from 1.6 to 3.4 percent. The magnitude of the estimated potential GHG emissions reductions for the truck mode in 2025, which is 410×106 tons CO2 eq., is significantly higher than for any of the other four modes, which range from approximately 5×106 to 20×106 tons CO2 eq. The truck mode is estimated to contribute 66 percent of freight transportation GHG emissions in 2025 if none of the potential best practices are adopted. The total GHG emissions of this mode in 2025 are estimated to increase 67 percent over 2003 levels. If all identified potential best practices are implemented aggressively, 2025 GHG emissions could be reduced by as much as 28 percent compared to 2003 levels. Of other modes, each of the other four modes is estimated to contribute 12 percent or less to total freight GHG emissions in 2025. If no potential best practices are implemented, modal GHG emissions in 2025 from the rail, air, water, and pipeline ES-9

modes are estimated to increase 49, 65, 28, and 15 percent, respectively, compared to 2003 levels. If all identified potential best practices are implemented aggressively, 2025 GHG emissions could increase by 20, 8, 22, and 9 percent, respectively, compared to 2003 levels, which is smaller than the increase if no potential best practices are implemented. In sum, if all identified practices are implemented aggressively, the possible net decrease in total freight transportation GHG emissions from 2003 to 2025 is 11%, even if energy use increases as currently projected. The magnitude of the estimated potential energy use reduction for the truck mode in 2025 is also significantly higher than for the other four modes. If no potential best practices are implemented, the truck mode is estimated to consume 70 percent of freight transportation energy in 2025. The truck mode energy use in 2025 is estimated to increase by 67 percent compared to 2003 levels. If all identified potential best practices are implemented aggressively, 2025 energy use could be reduced by as much as 12 percent compared to 2003 levels. Each of the other four modes are estimated to consume 12 percent or less of total freight energy consumption in 2025 If no best practices are implemented, total modal energy use in 2025 from the rail, air, water, and pipeline modes are estimated to increase 49, 65, 28, and 15 percent, respectively, compared to 2003 levels. If all identified potential best practices are implemented aggressively, these increases in energy use are estimated at 36, 8, 25, and 13 percent, respectively, compared to 2003 levels. These energy use increases with the implementation of all identified potential best practices are significantly less than those energy use increases without the implementation of all identified potential best practices. ES.4

Quantitative Assessment Results

To date, sufficient information has been obtained to assess the costs of 13 potential best practices quantitatively. Table ES-2 summarizes: reductions in GHG emissions and energy use; net savings; net savings per unit of GHG emissions reduction; and net savings per unit of energy use reduction, and simple pay-back periods of selected potential best practices. These 13 potential best practices vary substantially in terms of annual reductions in modal GHG emissions and energy use within their individual modes. Four best practices for the truck mode, which include auxiliary power units, direct-fired heaters, hybrid trucks, and B20 biodiesel, have the potential to achieve substantial GHG emissions reductions (8×106 ton CO2 eq./year or more). Two best practices for the truck mode, auxiliary power units and hybrid, also have the potential to reduce energy use substantially, by 185×1012 BTU or more. These 13 potential best practices vary substantially regarding their cost- effectiveness and simple pay-back periods. The most cost-effective best practices are: plug-in units for the rail mode; direct-fired heater for the truck mode; and combined diesel powered heating system and ES-10

2-2 2-3

Water

2-6 4-5

Pipeline

5-1

a b c d

5-2 5-3

B20 Biodiesel for Ships Convert Natural Gas Pneumatic Controls to Instrument Air Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices “Hot Tap” Method

Simple Pay- back period (year)

Rail

2-1

Net Saving per Unit of Energy Use Reduction ($/106 BTU)

1-3 1-4 1-21 1-33

Off-Board Truck Stop Electrification Auxiliary Power Units Direct Fire Heaters Hybrid Trucks B20 Biodiesel for Trucks Combined Diesel Powered Heating System and Auto Engine Start/stop System Battery Diesel Hybrid Switching Locomotive Plug-In Unit B20 Biodiesel for Locomotives

Net Saving per Unit of GHG Emission Reduction ($/ton CO2 eq.)

Truck

1-1

Practice Name

Net Saving ($106/year)

I.D. No.

2.4

27

330

138

12

N/Ac

15 7.6 24.5 30.8

185 94 300 -370

440 1350 3190 -3300

29 178 130 -108

2.3 14 11 N/Ab

3.2 0.6 2.1 N/Ad

2.3

29

390

167

14

2.1

1.1

14

70

65

5.2

5.5

0.4

4

135

364

38

0.8

3.5

-42

-380

-109

N/Ab

N/Ad

1.5

-18

-180

-120

N/Ab

N/Ad

0.7

1

12

18

9.6

0.3

0.8

2

13

18

8.8

0.9

2.5

5

40

16

7.8

0.2

Modal GHG Emission Reduction (106 ton CO2 eq./year) Modal Energy Use Reduction (1012 BTU /year)

Mode

Table ES- 2. Summary of Potential GHG Emissions Reductions, Energy Use Reduction, Net Savings, Unit Net Savings, and Simple Pay-back Periods of Selected Best Practicesa

These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. There is no pay-back period for this best practice because there is no initial capital cost to users. There is no pay-back period for this best practice because there is no net saving.

ES-11

auto engine start/stop system for the rail mode. The least cost-effective best practices are B20 biodiesel for the truck, rail and water modes. Five best practices have simple pay-back periods of less than 1 year. From a national policy perspective, consideration of the potential magnitude of reductions is important. From an individual owner or operator perspective, consideration of cost savings and cost effectiveness may be more important. Even larger percentage reductions are possible if intermodal shifts, such as from truck to rail, are possible. The complete rail-truck intermodal shift could reduce GHG emissions for the truck mode by 85 percent, if no potential best practices are implemented for either mode. Whether intermodal shift is possible depends on site-specific characteristics. ES.5

Major Findings

Many potential best practices exist to reduce energy and refrigerant use, which could lead to reductions in GHG emissions. If potential best practices are aggressively implemented, it is possible for there to be a net decrease in total GHG emissions and energy use in freight transportation. Potential additional reductions might be possible if certain intermodal shifts are encouraged where possible. Limited quantitative data is available upon which to base assessments of the costs of potential best practices. For thirteen potential best practices for which adequate data are available, the normalized cost savings per unit of GHG emissions reduction was highly variable. Ten of these potential best practices produce net cost savings because of significant energy cost savings. Three of them have net cost increases because they involve substitution of alternative fuel. Switching from petroleum to biodiesel can reduce GHG emissions but increase total costs, based on recent fuel prices. Governments and individual owners or operators are encouraged to carefully compare their options. From a national policy perspective, some potential best practices, such as direct fired heaters and B20 biodiesel for the truck mode, offer greater potential for large magnitudes in reduction of total GHG emissions, but may not be as cost-effective as other practices. Additional research and development might result in reduced costs. From an individual owner or operator perspective, consideration of cost savings and cost effectiveness are more important. Some potential best practices may be a “no regrets” proposition and the owner or operator can realize a net cost savings. This guidebook makes no recommendations about the use of specific strategies as best practices because typically information for best practices is incomplete and does not enable situation-specific assessment and comparison. While it is clear that many potential best ES-12

practices will not be considered by potential adopters until adequate cost data is available upon which to estimate costs reliably, at this time insufficient data are available to characterize costs reliably for most of the best practices identified here. ES.6

Recommendations

Information given here can be updated as new information becomes available. In this work, costs could be assessed for only 13 best practices. Since potential adopters of best practices need cost data for all of the possible best practices, there is a critical need for more cost information. Ongoing work is recommended to obtain or develop cost estimates for best practices for which costs are not reported here, as well as to update cost estimates reported here as new data become available. The impact of variations of key assumptions, such as market penetration rates, fuel prices, capital costs, and operation and maintenance costs, can be assessed via sensitivity analysis. Developing tools to support decision making regarding best practices are also recommended. Effective best practices are developed based on the conditions faced by a specific decision-maker, such as local fuel costs. It is critical to develop a decision support framework that will allow such parties to compare multiple best practices on the basis of representative and relevant important assumptions. A decision tree is helpful in situations of complex multistage decision problems for choosing best practices and can be applied to assist individuals in choosing from among many best practices. A decision tree involves a hierarchical cascade of questions to guide decision-maker toward promising best practices appropriate to their situations. The decision tree could be implemented in an interactive web-based format and may be publicly accessible.

ES-13

1.0 PURPOSE AND BACKGROUND Freight transportation is comprised of five major modes: truck, rail, air, water, and pipeline. Greenhouse gas (GHG) emissions from freight transportation account for approximately 9% of total greenhouse gas emissions in the United States.1,2,3 The contributions of these modes to total freight transportation GHG emissions are 60, 6, 5, 13, and 16 percent, respectively. Energy use for all freight modes, based on a long-term energy trend scenario, is estimated to increase approximately 75% from 2003 to 2030.4 Given this expected increase in the next quarter of this century, and since GHG emissions are largely based on energy use, GHG emissions from freight transportation are also expected to increase significantly in the future. There are a growing number of technological and operational strategies that could reduce GHG emissions from the freight sector. However, knowledge of these technological and operational strategies is not widespread. The objectives of this project are to review and investigate existing technological and operational emission reduction strategies, and to develop a guidebook summarizing potential best practices within the freight transportation sector. The objectives of this guidebook are to: (1) review existing technological and operational strategies to reduce greenhouse gas emissions, directly or indirectly, within the freight transportation sector; (2) develop a list of innovative technological and operational strategies (ongoing or completed) that can be considered as potential best practices; and (3) summarize and compare the various potential best practices. 1.1

Purpose of This Guidebook

A growing number of technological and operational strategies could reduce GHG emissions from the freight transportation sector.6-10 For example, as shown later, 14 identified energy efficiency strategies for the truck mode have the potential to reduce 3 billion gallons of fuel use and 33 million tons CO2 eq. annually in 2010,11 which is about 7% of the 2010 greenhouse gas emissions from the truck mode in the United States. These technological and operational strategies could offer freight transport owners and operators added benefits, such as: (1) lower fuel costs (if the program helps reduce fuel usage); (2) lower refrigerant costs (if the program helps reduce HFC usage); and (3) lower emissions of GHG and of air pollutants. Reductions in fuel or refrigerant usage would provide direct cost benefits to owners and operators, thereby creating at least partial incentives to adopt such technologies and programs. However, knowledge of existing technological and operational strategies, and their effectiveness at reducing greenhouse gas emissions, is not widespread throughout the freight transport community. An investigation of these strategies is needed to provide a consistent 1

basis for identification and comparison of methods that are available to the freight sector to reduce GHG emissions. In addition, some technological and operational strategies, such as fuel and refrigerant saving strategies, that could have significant greenhouse gas reduction benefits, may not have originally been developed with respect to an objective of GHG emissions reduction. Efforts to reduce fuel or refrigerant use typically provide an added benefit of reducing GHG emissions. Thus, identifying and fostering the application of technological and operational strategies that can reduce GHG emissions, and fostering similar efforts, can provide multiple benefits of enabling choices that lead to reductions in greenhouse gas emissions. Such choices may often also reduce fuel use, other air pollutant emissions, and costs. This project supports knowledge-sharing through a guidebook on current best technological and operational strategies within the freight transportation sector. Best practices are typically undertaken by responsible parties at the local, state, and Federal government levels, or at the levels of individual or fleet owners and operators. This best practice guidebook is intended to provide information useful to responsible parties in the freight transportation sector in identifying, evaluating, and adopting similar technological and operational strategies. 1.2 Background The freight transportation sector contributes significantly to greenhouse gas (GHG) emissions in the United States. The most important greenhouse gas is carbon dioxide (CO2), which is produced primarily from combustion of fossil fuels.1,5 Other important greenhouse gases include methane (CH4), nitrous oxide (N2O), and hydrofluorocarbons (HFCs).1,12 HFC-134a is the most common HFC. Greenhouse gases are often compared based on their global warming potentials (GWPs). Global warming potentials are an indicator of the globally averaged relative radioactive forcing impacts of a particular GHG. CO2 is assumed as a datum with a GWP = 1. The GWPs of CH4, N2O, and HFC-134a are 21, 310, and 1,300, respectively.1,13 These GWPs are used to convert the mass emissions of CH4, N2O, and HFCs to an equivalent mass of CO2 with the same overall global warming impact.1 In 2003, total greenhouse gas emissions in the United States were estimated as 7,789×106 tons CO2 eq., including 94×106 tons CO2 eq. emissions from international aviation and marine transportation activities. The freight transportation sector in the United States emitted more than 719.8×106 tons CO2 eq. Thus, the freight transportation section is responsible for approximately 9.1 percent of the estimated total GHG emissions in the United States.1-3 The truck mode emits approximately 60% of GHGs in freight transportation, which is approximately 5.4% of U.S. GHG emissions. The freight transport activities and GHG emissions in the freight 2

transportation sector are summarized in Table 1-1.1-3 Table 1- 1.

Greenhouse Gas Emissions from the Freight Transportation Sector in 2003 GHG Emissions (106 Tons CO2 eq.)1-3

Mode of Freight Transportation

Freight Transport Activity (Billion Ton-miles)

CO2

CH4

N2O

HFCs

Total

Trucks

1256

419.5

0.1

1.9

10.4

431.9

Rail

1550

42.9

0.1

0.3

-

43.3

Air

34

35.8

+

0.3

-

36.1

Water

1588

95.0

0.1

0.2

-

95.3

Pipeline

278

38.3

74.9

-

-

Total

4706

631.5

75.2

2.7

(10.4)

113.2 a

719.8

1

a: Data here only include the amount of HFC emissions for the truck mode. No detailed data are currently available for the amount of HFC emissions for the other four modes. Thus, the number shown here is a lower bound on freight transportation HFC emissions.

These emissions are typically associated with combustion processes or leaks, the latter of which are also known as fugitive emissions. For example, CO2 is emitted primarily as a result of combustion of carbonaceous fuels (e.g., diesel fuel, jet fuel, residual fuel oil and natural gas). Methane can be emitted as a result of incomplete combustion of fuels and because of leaks in natural gas pipelines. N2O is emitted partly as a product of combustion and partly as a byproduct produced in some catalytic emission control systems. HFCs are typically emitted because of leakages in refrigeration and air conditioning systems. Of these four GHGs, the most reliable data are for CO2. HFCs emissions for truck mode have been estimated, but there are not readily available HFC emissions data for other freight modes.1 The data in Table 1-1 indicate that the majority of freight-related CO2 and N2O emissions are associated with trucks, whereas the majority of CH4 emissions are attributed to natural gas pipelines. Thus, GHG reduction strategies may be prioritized within these areas. Those modes that involve the use of refrigeration or air conditioning systems would be a priority for technological and operational strategies that could reduce HFC emissions. However, when considering the total global warming impact, CO2 emerges as the highest priority among the four GHGs considered here. Thus, CO2 emissions from trucks are a major focus area. A scenario of total freight-related GHG emissions over time, which is shown in Table 1-2, is developed based on estimated GHG emissions in 2003 and an energy trend scenario for all modes. The latter comes from a long-term energy trend scenario, “2005 Technology Case,” in the Energy Information Administration’s Annual Energy Outlook 2006, in which freight 3

transportation energy use is estimated to increase approximately 52% from 2003 to 2025.4 Since energy use for freight transportation will increase significantly in the next quarter of this century, and GHG emissions are largely based on energy use, GHG emissions from freight transportation are also estimated to increase significantly in the future. According to the scenario, greenhouse gas emissions for freight transportation are estimated to increase approximately 52% from 2003 to 2025. Table 1- 2.

A Scenario of GHG Emissions from Freight Transportation from 2003 to 2025 Annual GHG Emissions (106 Tons CO2 eq.)

Mode of Freight Transportation

2003

2010

2015

2020

2025

Growth 2025 vs. 2003

Truck

432

520

588

649

721

67%

Rail

43

50

53

58

65

49%

Air

36

44

52

57

59

65%

Water

95

108

111

118

122

28%

Pipeline

113

107

121

131

130

14%

Total

720

828

925

1012

1096

52%

Governments and the freight industry recognize the need for technological and operational strategies as to meet future challenges.2 There are a growing number strategies, either existing or developing, that could reduce GHG emissions from the freight sector. There is a need to review and characterize these strategies in order to support decision making regarding their potential adoption. 1.3

Using This Guidebook

This guidebook presents a survey of potential best practices for reducing energy use and GHG emissions in freight transportation. The survey includes characterization of each potential best practice in order to serve the information needs of responsible parties and decision makers. The organization and contents of this guidebook are summarized in Figure 1-1. Brief descriptive information regarding each potential best practice, which are sorted by subgroup, are described in Chapters 4 to 8 for the truck, rail, air, water, and pipeline modes, respectively. The potential reductions in GHG emissions and energy or refrigerant use for all modes are summarized in Chapter 9. Intermodal comparisons and intermodal shifts are discussed in

4

Background and Methodology Definitions and Concepts Chapter 2

Methodology Chapter 3

Fuel Properties Appendix F

Assessments of Individual and Subgroups of Best Practices by Mode Mode Truck Rail Air Water Pipeline

Summary Material Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8

Supporting Details Appendix A Appendix B Appendix C Appendix D Appendix E

Summaries of and Comparisons Between Modes Chapter 9

Figure 1- 1.

Conclusions and Recommendations Chapter 10

Overview of the Organization and Content of This Guidebook.

Chapter 9. For the potential best practices for which quantitative cost data are not available, they are assessed qualitatively. Assessment results for these are given in simplified summary tables in Appendices A through E for the truck, rail, air, water, and pipeline modes, respectively. For the best practices for which quantitative cost data are available, they are assessed quantitatively. Assessment results are given in standardized reporting tables. Details of the analyses of these practices are given in Appendices A through E for the truck, rail, air, water, and pipeline modes, respectively. The properties, CO2 emissions coefficients and average unit costs of fuels discussed are given in Appendix F. This guidebook is intended as a starting point of choosing and implementing strategies for the freight transportation sector in order to reduce GHG emissions. This guidebook is aimed at providing useful information to responsible and target parties regarding opportunities for 5

reducing energy use, refrigerant use, and GHG emissions, as well as regarding the possible magnitude of such reductions. This guidebook contains brief information for many potential best practices in order to provide a comprehensive introduction to possible choices. This guidebook makes no recommendations regarding the use of specific strategies as best practices. Typically, information for best practices is incomplete and does not enable situation-specific assessment and comparison.

6

2.0 DEFINITION OF KEY CONCEPTS This Chapter defines key terms concepts pertaining to “best practices,” transportation modes, organizations responsible for adopting best practices, greenhouse gases, types of strategies of best practices, and the developmental status of these strategies. 2.1 “Best Practices” for Greenhouse Gas Reductions in Freight Transportation Best practices for greenhouse gas reductions in freight transportation are defined here as strategies within the freight transportation sector, whether they are technological or operational (see Section 2.4 for definitions), that are, or can be, implemented by responsible parties and that have been demonstrated to reduce, or have the potential to achieve reductions in, GHG emissions.14 Since the best practices identified are often of potential future applicability, they are referred to as potential best practices. Within the broad category of all best practices, there are distinguishing criteria that can be used to compare and evaluate specific practices. A framework for categorization and characterization of each best practice is described in Section 3.1. Best practices typically achieve GHG emissions reductions by reducing the use of energy, refrigerants, or both. Thus, this guidebook explicitly considers the capability of potential best practices to reduce GHG emissions, energy use, and refrigerant use. 2.2 Modes of Freight Transportation Freight transportation, defined as the transportation of commodities, is comprised of five major modes: truck, rail, air, water, and pipeline.15 Highway transportation of freight is usually referred to as the “truck” mode.16 The standard measure of the activity of the truck mode is vehicle miles traveled (VMT). FHWA breaks down VMT figures by vehicle types. FHWA defines two types of trucks: (1) single-unit, 2-axle 6-tire,or 3+ axle trucks; and (2) combination trucks (single trailer and multiple trailer).2,17 Trucks can also be classified based on other vehicle characteristics, such as cab type, body type, vehicle size, and gross vehicle weight, which are defined by U.S. Bureau of Census.18-19 Classifications by cab type include: conventional cab (with sleeper, without sleeper, and others); cab over engine (with sleeper, without sleeper, and others); and cab forward of engine (cab beside engine and others).18 Classifications by body type include: (1) single-unit trucks, such as van, tank, and crane; and (2) truck-tractors, which have many types of trailers, such as automobile carrier, livestock, van, tank, and mobile home toter.18 7

Classifications by vehicle size include: light, medium, light-heavy, and heavy-heavy.18 Classifications by gross vehicle weight (GVW) are summarized in Table 2-1.18-19 The relationship among vehicle size, gross vehicle weight, number of axles, and number of tires are summarized in Table 2-1.18,20-21 Following the definitions of FHWA and U.S. Bureau of Census, the truck mode excludes trucks which gross vehicle weights are smaller than 10,000 pounds (Class 1 and Class 2 trucks). Railroad freight transportation is referred to the “rail” mode. This mode includes freight transport on Classes I, II, and III railroads, as well as switching and terminal carriers.2 Class I railroads, which had operating revenues of at least $277.7 million in 2003, concentrate on long-haul, high-density intercity traffic lanes, and account for 93 percent of U.S. freight railroad revenue. Class II railroads are line-haul railroads with at least 350 route-miles, with revenues between $40 million and the Class I threshold, or both. Class II railroads are also called regional railroads because they typically serve a region located in two to four states. Class II railroads account for 3 percent of U.S. freight railroad revenue. Class III railroads operate less than 350 route-miles and earn less than $40 million per year. Class III railroads are also called local line-haul carriers because they typically serve a single state. Class III railroads account for 2 percent of U.S. freight railroad revenue. Switching and terminal carriers account for 2 percent of U.S. freight railroad revenue.22 Class I railroads consume more than 94 percent of railroad fuel.2 Thus, a priority for greenhouse gas reduction within the rail mode is the Class I railroads. Air freight is transported in dedicated cargo aircraft and in cargo space of passenger aircraft. The latter is referred to as belly cargo. Both types of aircraft carry a significant amount of air cargo. In order to estimate aircraft emissions attributable to freight alone, it is customary to apportion passenger aircraft into passenger and freight components based on passenger and cargo weight.2 Water (or waterborne) freight transportation includes domestic commerce and international trade,16 and includes ships, barges, shallow draft vessels and deep draft vessels.23 Foreign trade accounts for 58 percent of waterborne tonnage, with import tonnage nearly 2.7 times more than export tonnage. Domestic waterborne tonnage is primarily inland movements (rivers and canals), with smaller amounts moving along the coasts, in the Great Lakes, and within ports.2 In 2003, domestic water trade consumed 797 Tera BTU of energy, including 302 Tera BTU of distillate fuel oil and 495 Tera BTU of residual fuel oil.1, 3 Foreign water trade, at consumed 322 Tera BTU of energy, including 83 Tera BTU of distillate fuel oil and 239 Tera BTU of residual fuel oil.1 The pipeline mode includes the movement of natural gas and oil. However, this guidebook refers only to the movement of natural gas via the pipeline mode because of insufficient 8

Truck Classifications by Weight, Number of Axles, and Number of Tires19,21

Table 2- 1. Vehicle Size

Class Gross Vehicle Weight (lbs) Number of Axles

Number of Tires

Light

1

33,000

3

10

3+

10 +

Medium

information for the movement of oil.3 The well-to-use of the pipeline system includes several stages: production, processing, transmission and storage, and distribution.1 In this guidebook, the transmission and distribution stages of the pipeline mode are considered. The pipeline mode emits carbon dioxide from burning methane as the fuel for powering the pipeline systems, and it also directly emits methane to the atmosphere, which includes fugitive emissions and vented emissions. Most of the methane emissions in the freight transportation are from the pipeline mode. 2.3 Subgroup A subgroup within a mode is a collection of potential best practices in a mode that have either common goals or attributes. Subgroups are defined based on the factors that the practices can improve (e.g., in the case of the truck mode, idling, aerodynamics, rolling resistance, vehicle weight), or the technologies that vehicles or devices may apply (e.g., hybrid diesel-electric propulsion system, alternative fuels), to reduce GHG emissions. 2.4 Responsible Parties A responsible party is a person or organization who has the authority to develop, promote, or select a best practice. Responsible parties can be classified as individuals (vehicle owners or operators), companies (fleet owners or manufacturers), and governments (local, state, and central governments in the United States and in other countries). When the strategies are in conceptual or developmental stages, academic institutions and non-governmental organizations may be also involved as responsible parties. For example, many universities are involved in projects to 9

study strategies that have the potential to reduce energy use and GHG emissions, such as anti-idling, hybrid vehicles, and alternative fuels. 2.5 Target Parties A target party is a person or organization who may implement a best practice. Target parties are classified as individuals (vehicle owners or operators) and companies (fleet owners). 2.6

Greenhouse Gas Emissions

The operation of freight transportation is responsible for the emissions of four major greenhouse gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and hydrofluorocarbons (HFCs), which have different GWPs, as discussed in Section 1.2. These four gases are considered. However, priority is given to CO2 since it is emitted in the largest quantity with respect to global warming potential. 2.7 Strategy Types for Reducing Greenhouse Gas Emissions There are two general types of best practice strategies. A strategy can be either technolgical or operational.2 These two categories are defined here. 2.7.1 Technological Strategies Technological strategies modify, replace, or enhance a piece or system of equipment, its fuel, or its refrigerant to reduce GHG emissions. As examples, technological strategies may involve replacing an existing engine with a new one, converting diesel-powered equipment to electrical power, using alternative fuels or refrigerants, replacing older freight equipment, having an engine repaired or rebuilt, or improving fuel economy.2 2.7.2 Operational Strategies Operational strategies change the way that vehicles and freight transportation systems operate, resulting in fewer GHG emissions. These strategies may reduce fuel or refrigerant uses and result in lower operating costs for the equipment owner. These strategies may involve improving freight operating efficiency (e.g., minimizing “empty mileage,” which refers to the movement of empty commercial vehicles) through improved freight logistics results in greater fuel productivity and more ton-miles of freight moved per unit of fuel consumption),2 reducing congestion, reducing unnecessary idling, reducing empty mileage, increasing load factors, eliminating circuitous routing, and others. Assessing the effect of these operational strategies on emissions, however, can be difficult because there may be little relevant quantitative 10

information. In some cases, extensive modeling of the performance of an integrated freight transportation system could be required, which is beyond the scope of this work.2 2.8 Practice Goals Practice goals include the percentage reductions in GHG emissions, energy use or refrigerant use. The goals may be specific to particular transportation technologies or devices. A particular practice may only be applicable to a fraction of all devices within a mode. For example, anti-idling strategies for the truck mode are only applicable for long-haul trucks with sleeper cabs that typically have extended idling for mandatory driver rest periods. This particular type of trucks contributes only a fraction of all freight transport activity within the truck mode. Percentage reductions in GHG emissions, energy use or refrigerant use are estimated based on the difference in 2025 modal GHG emissions, energy use, or refrigerant use with and without the selected potential best practice, divided by the total modal emissions if no potential best practice is implemented. 2.9 Developmental Status Developmental status includes new concepts, pilot tests, and commercially available systems. New concepts include basic research activities, applied research activities, and experiments at the laboratory level. Pilot tests include prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now.

11

3.0 METHODOLOGY The methodology for characterizing and evaluating potential best practices includes: reviewing literature to identify existing or developing potential best practices and to develop a preliminary list of potential best practices; categorizing and characterizing potential best practices; assessing their reductions in GHG emissions, energy use or refrigerant use; assessing annualized practice costs, and energy or refrigerant costs reductions; assessing cost savings; and summarizing and reporting assessment results. The potential best practices identified here are often of potential future applicability, since many of them have not been implemented widely and some are preliminary concepts. Thus, in many cases, there is not adequate data available with which to quantify cost. Therefore, the methodology includes both qualitative and quantitative approaches. 3.1 Literature Review A list of potential best practices was identified, mostly based on literature review. Most data and information regarding potential best practices was taken from published technical and policy reports, books, and engineering journal papers, although some information was collected from websites. Some information was collected from personal communications with experts via email and telephone. 3.2 Reductions in GHG Emissions, and Energy or Refrigerant Use, for Individual Best Practices Quantitative assessments were made for reductions in GHG emissions, energy use or refrigerant use in all cases, and for practice cost, energy or refrigerant cost reduction, and cost savings, where sufficient data were available. Where quantitative cost data were not available, the resource implications of the practices are discussed qualitatively in a structured approach. The percentage contributions of CO2, CH4, N2O and HFCs emissions to the total GHG emissions in terms of CO2 equivalent for all five modes are listed in Table 3-1, based on the results of Table 1-1. The total GHG emissions for the truck mode are mainly contributed by CO2 emissions from fuel use. A small fraction of the total freight truck GHG emissions is contributed by HFCs emissions from refrigerant use. The contributions of CH4 emissions and N2O emissions to the total freight truck GHG emission are insignificant. Thus, the opportunities to significantly reduce freight truck GHG emissions are based on reductions in CO2 and HFC emissions. 12

Table 3-1.

a

Contribution of Selected Greenhouse Gases to Total Modal Greenhouse Gas Emissions

Greenhouse Gases

Percentage Contribution to Each Freight Transport Mode (%) Truck

Rail

Air

Water

Pipeline

CO2

97.1

99.1

99.2

99.7

33.8

CH4

0.0

0.2

0.0

0.1

66.2

N2O

0.4

0.7

0.8

0.2

N/Aa

HFC

2.4

N/Aa

N/Aa

N/Aa

N/Aa

No data are currently available. The total GHG emissions for the rail, air and water modes are mainly contributed by CO2

emissions from fuel use, which are also illustrated in Table 3-1. The contributions of CH4 emissions, N2O emissions and HFC emissions to the total GHG emission are either insignificant or having no available data currently. Thus, the opportunities to significantly reduce GHG emissions for these three modes are based on reductions in CO2 emissions. CH4 is larger contributor to total GHG emissions for the pipeline mode than CO2, as shown in Table 3-1. For potential best practices for the pipeline mode, the reductions in GHG emissions are based on reductions in CH4 emissions. Reductions in GHG emissions and energy use for all potential best practices, except those based on alternative fuel strategies, are estimated based on direct emissions inventories. Reductions for alternative fuel strategies are estimated based on life cycle inventories. Reductions in refrigerant use are estimated based on estimates of the refrigerant leakage rate reduction or the GWP difference between low global-warming-potential refrigerants and original refrigerants. While the scope of this work includes the estimate of GHG emissions, energy use, and refrigerant use, for simplicity and brevity we simply use the term “emissions” in this section. Per-device reductions for each potential best practice, except for alternative fuel strategies, are estimated based on the differences in per-device emissions with or without use this potential best practice divided by per-device emissions if no potential best practice is implemented. Reductions for alternative fuel strategies are estimated based on life cycle inventories. The potential reductions in modal GHG emissions and energy or refrigerant use for an identified potential best practice are estimated based on the difference in 2025 modal emissions with and without the selected potential best practice divided by the total modal emissions if no potential best practice is implemented. Since a particular practice may only be applicable to a fraction of all devices within a mode and these applicable devices contribute only a fraction of all 13

freight transport activity within this mode, the reductions in modal emissions for this practice is also a fraction of its per-device reductions. For example, trucks of all types are estimated to carry 2.1 trillion ton-miles per year. Long-haul trucks with sleeper cabs, which are a portion of all trucks, carry 450 billion ton-miles per year. Since strategies aimed at avoiding extended idling during rest periods can be only adopted by these long-haul trucks, these strategies are only applicable to, at most, 21 percent of total truck freight movement. The transport activity to which anti-idling strategies are applicable is, therefore, a portion of the transport activity of the freight truck industry. An assumption is made that each potential best practice can reach a potential best estimate of maximum market penetration by 2025. Technical, practical, and cost barriers are not quantified here. Actual market penetration may be lower than estimated. However, the estimates provide a useful upper bound as to what might be achieved if adoption of such practices is given practically. Details of these assumptions are given in Appendices A through E. 3.3 Quantitative Assessments of Best Practices For all potential best practices, quantitative estimates are given for reductions in GHG emissions, energy use, and refrigerant leakage or GWPs. Furthermore, where sufficient data are available, quantitative assessments for cost effectiveness are performed for: practice cost; energy or refrigerant cost reduction; net savings per unit of reductions in GHG emissions and energy or refrigerant use; and simple payback period. The characteristics and the assessment results of the potential best practices are summarized in standardized reporting tables. 3.3.1. Quantifying Cost Implications The methods for estimating the reductions in GHG emissions, energy use or refrigerant use are described in Section 3.2. Total net savings of implementing a potential best practice is the difference between annual energy or refrigerant costs savings and the annualized costs, the latter of which includes levelized capital costs and annual operation and maintenance costs. Net savings are normalized per unit of reduction in GHG emissions or energy or refrigerant use. A positive value of net savings means that the potential best practice will pay for itself over some period of time, whereas a negative value means that the annualized costs exceed savings associated with reductions in energy use, refrigerant use, or both. Simple payback periods are estimated based on the number of years required to recoup any additional capital or initial costs that lead to reductions in energy or refrigerant use (or any other cost-saving benefits). Such estimates are based on a discount rate of zero. These estimates are 14

made where adequate data are available. 3.3.2 Summarizing and Reporting the Results For each potential best practice for which sufficient information is available for a quantitative assessment, a standardized reporting table, which includes three parts, is used to report its quantitative characteristics and assessment results. The standardized reporting table is given in the format of Table 3-2. The first part of the table summarizes the characteristics of the potential best practice, including: practice name; applicable mode type; subgroup; responsible parties and target parties; targeted GHGs; strategy type; practice goals; developmental status; and practice summary. Each of these is briefly explained. (1) Practice name: The name of the technology or operation. (2) Mode type: Mode types are sorted by code: 1 = truck; 2 = rail; 3 = air; 4 = water; and 5 = pipeline. (3) Subgroup: Each mode type can be divided into two or more subgroups based on the factors that the practices can improve or the technologies that devices may apply. For example, the truck mode is divided into anti-idling, air conditioning system improvement, aerodynamics improvement, tire rolling resistance improvement, and other subgroups. (4) Responsible parties: These are categorized by individuals, companies, research institutions, local governments, state governments, and Federal government. A standardized list of responsible parties is given in Table 3-3. (5) Target parties: These are categorized by individuals and companies. As noted in Section 2.4, target parties may differ from responsible parties. A standardized list of target parties is also given in Table 3-3. (6) Target GHGs: CO2, CH4, N2O, HFCs, or combinations of these. (7) Strategy type: Technology, operational, or both. (8) Practice goals: Practice goals include the types of devices that can adopt this practice and percentage reductions in GHG emissions, energy use or refrigerant use. Devices that can adopt this practice may be only a portion of all devices in the industry. (9) Developmental status: Developmental stages are sorted by code: N = new concepts; P = pilot tests; and C = commercially available systems. (10) Practice summary: A brief description of the implementation of the practice.

15

Table 3- 2.

The Format of Standardized Reporting Table

Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP)a Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER)b Unit Energy Use Reduction (UER)c Unit Refrigerant Use Reduction (URR)d Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a)e Annual O & M Cost (AOM) Annualized Cost (AC)f Annual Energy Cost Saving (AECS) Annual Refrigerant Cost Saving (ARCS) Net Savings (NS)g Net Savings per Unit of GHG Emissions Reductions (NSGR)h Net Savings per Unit of Energy Use Reduction (NSER)i Net Savings per Unit of Refrigerant Use Reduction (NSRR)j Simple Payback Period (SPP)k

a:

Description

Unit 109 ton-miles/year

Value

109 ton-miles/year 106 ton CO2 eq./year 1012 BTU /year lbs/year 10-3 lb CO2 eq./ton-mile BTU /ton-mile lbs/ton-mile 106 USD ($) % years year-1 $106 /year $106 /year $106 /year $106 /year $106 /year

10%

$/ton CO2 eq. $/106 BTU $/lb years

Each practice may only be applicable to a fraction of all devices within a mode. Thus, annual transport activity to which a practice is applicable (ATAP) is the transport activity performed by the fraction of all devices within a mode to which a practice can be applied, and ATAP is a fraction of annual transport activity for the mode (ATAM).

b: Unit GHG Emissions Re ductions (UGER ) = (Continued on next page)

16

AGR ATAP

(Table 3-2. continued) AER ATAP ARR d: Unit Re frigerant Use Re duction (URR ) = ATAP

c: Unit Energy Use Re duction (UER ) =

e:

Fixed charge factor depends on the discount rate (r) and the technical lifetime (L). Fixed Ch arg e Factor (a ) =

1

  1   ∑   i=1  (1 + r )i      f: Annualized Cost (AC ) = (C × a ) + AOM g: Net Savings (NS ) = (AECS or ARCS ) − (C × a ) − AOM L

h: Net Savings per Unit of GHG Emissions Re ductions (NSGR ) = i: Net Savings per Unit of Energy Use Re duction (NSER ) =

NS AER

j: Net Savings per Unit of Refrigeran t Use Re duction (NSRR ) = k: Simple Payback Period (SPP ) =

C AECS or ARCS − AOM

(

)

17

NS AGR

NS ARR

The second part of the standardized reporting table includes: the magnitude of transport activity for the entire mode; the magnitude of transport activity to which the practice is applicable; total GHG emissions reductions per year; total energy use reduction per year; total refrigerant use reduction per year; and reductions per unit of freight transport (e.g., GHG emissions reductions per unit of freight transport, which has the unit of lb CO2 eq. per ton-mile). The third part of the standardized reporting table focuses on cost. This part includes: annualized costs; energy or refrigerant costs savings; net savings per unit of reduction in GHG emissions and energy or refrigerant use; and simple payback period. 3.4 Qualitative Assessments of Best Practices For each potential best practice for which there is a lack of adequate quantitative data and detailed information, qualitative assessments results are summarized in a simplified summary table, which is given in the format of Table 3-4. A simplified summary table includes: (a) technological information; (b) percentage reductions in GHG emissions, energy use or refrigerant use; (c) cost information; and (d) a description of benefits and drawbacks of the practice. Technological information includes: practice name; applicable mode type; subgroup; responsible parties; target parties; target GHGs of interest; strategy type; practice goals for GHG emissions reduction; developmental status; and a brief summary of the practice. The information for these items has been explained in Section 3.3.2. The second part of the table includes the potential reductions in modal GHG emissions, energy use or refrigerant use for individual potential best practices, which are quantitatively. Cost information is any available knowledge, such as capital cost assumptions, cost premiums or cost savings assumptions and retail price impacts reported in the literature. Benefits and drawbacks of the potential best practice are also discussed and summarized. However, typically such information is incomplete and does not enable estimation of net cost savings in the same manner as for those practices for which detailed quantitative information is available. 3.5 Aggregated Reductions in GHG Emissions, Energy or Refrigerant Use for Multiple Best Practices Aggregate reductions in modal GHG emissions, energy use, or refrigerant use for an individual subgroup are estimated based on a simple linear combination of the reductions for multiple best practices within the subgroup, except as noted below.

18

Table 3- 3. A Standardized List of Responsible Parties and Target Parties24 Mode Category Responsible Parties Target Parties Individuals

1. 2. 3. 4.

Individual truck drivers Fleet truck drivers Truck loading operators Truck maintenance workers

5. 6. 7. 8.

10. 11 . 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

Truck operating companies Truck manufacturing companies Truck trailer manufacturing companies Electrical and electronic equipment manufacturing companies Transmission and power train parts manufacturing companies Metal stamping companies Air-conditioning manufacturing companies Truck maintenance companies Truck stop or rest area owners Fuel companies Lubricant companies University Non-governmental organization National laboratory Private research institution Local governments State governments Federal government

23. 24. 25.

Locomotive drivers and crews Railroad operators Railroad maintenance workers

26. 27.

Railroad companies Railroad rolling stock manufacturing companies Railroad goods shippers Fuel companies Lubricant companies University Non-governmental organization National laboratory Private research institution Local governments State governments Federal government Aircraft pilots and crews Airport operators Aircraft maintenance workers

9. Companies Truck

Research Institutions

Governments

1. 2. 3. 4. 5.

Individual truck drivers Fleet truck drivers Truck loading operators Truck maintenance workers Truck goods shippers

6. 7.

Truck operating companies Truck maintenance companies Truck stop or rest area owners

8.

8. Individuals

Companies Rail


Governments

Air

Individuals

28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40.

Continued on Next Page.

19

9. 10. 11. 12. 13.

14. 15. 16.

Locomotive drivers and crews Railroad operators Railroad maintenance workers Railroad companies Railroad maintenance companies Railroad goods shippers

Aircraft pilots and crews Airport operators Aircraft maintenance workers

Table 3-3. Continued. Mode Category

Responsible Parties 41. 42. 43.

Companies

44.


45. 46. 47. 48. 49. 50. 51. 52. 53. 54.

Aircraft companies Aircraft manufacturing companies Aircraft engine and engine parts manufacturing companies Aircraft parts and auxiliary equipment manufacturing companies Airport operation companies Fuel companies Lubricant companies University Non-governmental organization National laboratory Private research institution Local governments State governments Federal government

55. 56. 57.

Ship captains and crews Port operators Ship maintenance workers

58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69.

Shipping companies Ship building and repairing companies Port operation companies Fuel companies Lubricant companies University Non-governmental organization National laboratory Private research institution Local governments State governments Federal government

70. 71.

Pipeline system operators Pipeline system maintenance workers

72.

Natural gas pipeline operation companies Natural gas pipeline system manufacturing companies University Non-governmental organization National laboratory Private research institution Local governments State governments Federal government

Air

Governments

Individuals

Companies

Water Research Institutions

Governments

Individuals

Companies

Pipeline Research Institutions

Governments

73. 74. 75. 76. 77. 78. 79. 80.

20

Target Parties

17. 18. 19.

Aircraft companies Airport operation companies Aircraft goods shippers

20. 21. 22.

Ship captains and crews Port operators Ship maintenance workers

23. 24. 25.

Shipping companies Port operation companies Ship goods shippers

26. 27.

Pipeline system operators Pipeline system maintenance workers

28.

Natural gas pipeline operation companies Natural gas shippers

29.

Table 3- 4. Attribute

The Format of Simplified Summary Tables Description

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks

Within a subgroup, it is possible that two or more best practices may be mutually exclusive in serving similar functions or requiring installation on the same location of a vehicle or system. In the case of mutual exclusion, the best practice with the highest estimated reduction is used in the estimate of total modal reductions for the subgroup. For example, three alternative refrigerants for air conditioning systems that could be used as best practices are mutually exclusive. Only one refrigerant can be used in an air conditioning system. CO2 is chosen here because it has the lowest GWP compared to the other candidate refrigerants and its potential reductions in modal GHG emissions are the highest. Thus, the estimates do not double count mutually exclusive best practices. In a subgroup, it is possible that several best practices are not mutually exclusive and could be implemented simultaneously. However, the total reduction may not be a simple linear combination of the reductions of each individual practice because the practices may have interactive effects. For example, the combined reduction in aerodynamic drags of several best practices would not be a linear sum of the drag reduction of each practice individually. Since there is a lack of data upon which to quantify the overall reduction associated with interactions among multiple best practices within a subgroup, each interactive effect are not quantified. The linear combination may tend to overestimate the maximum possible reductions for the subgroup. Total reductions in modal GHG emissions and energy or refrigerant use for all best practices are estimated based on summing the reductions of each subgroup. The contribution of a subgroup to total reductions in modal GHG emissions and energy or refrigerant use is 21

estimated, and it is normalized by dividing the aggregate reductions for a subgroup by total modal reductions for all best practices for this mode. 3.6 Intermodal Substitution In some situations, it may be possible to substitute one mode for another for a given shipment, either partially or fully. From the estimates of 2003 freight transport activities and GHG emissions for individual modes in Section 1.2, the unit GHG emissions of each of these modes are 0.69, 0.06, 2.15, 0.12, and 0.81 lb CO2 per ton-mile for truck, rail, air, water, and pipeline, respectively. If it were possible to substitute some or all of a trucking or air trip with transport by rail or water-borne vessel, there could be a reduction in GHG emissions. For example, instead of transporting goods by truck from the origin to the destination, it may be possible to transport the goods by truck from the origin to a rail terminal, continue the shipment by rail for most of the mileage of the trip, and offload the goods to a local truck for delivery at the destination. An upper-bound estimate of the reduction in GHG emissions from inter-modal substitution of rail for trucking can be developed by assuming that all of the truck transport ton-miles are replaced by the same amount of rail transport ton-miles. In reality, the substitution would not be complete, since some truck miles would likely be required at the origin, destination, or both. The methodology for assessment of intermodal substitutions is described in Section 9.6.3.

22

4.0.

BEST PRACTICES FOR THE TRUCK MODE

This chapter identifies and characterizes 33 potential best practices applicable to the truck mode. These best practices are divided into 11 subgroups, including: • reduction in fuel use and emissions during extended idling, • air conditioning system improvement, • reduction in aerodynamic drag, • reduction in tire rolling resistance, • hybrid propulsion, • weight reduction, • improved transmission efficiency, • improved diesel engine efficiency, • reduction in accessory load, • modifications in driver operational practices, and • alternative fuels. Additional details regarding all of these best practices are in Appendix A, including the basis for estimated reductions in GHG emissions, energy use, and refrigerant use. For five of these practices, sufficient data were available to quantify costs. 4.1

Anti-Idling

Long distance truck drivers are required to take mandatory rest stops. These rest stops are intended to promote safety by reducing driver fatigue. Approximately 0.68 million long-haul trucks are equipped sleeper cabs.3 Sleeper cabs contain a small living environment with sleeping accommodations. The advantage of a sleeper cab is that the driver can take rest stops at any location where the truck can be parked, rather than have to stay at a hotel. Such compartments require heating, ventilation or air conditioning (HVAC), often have small appliances such as refrigerators and microwave ovens, and have electrical outlets to support other auxiliary loads such as television or computers. Conventionally, the heating, cooling, and power requirements for the sleeper cab during driver rest time are supplied by the diesel-fueled base engine of the truck. These engines are run under extended idling conditions for continuous periods of many hours. According to the literature, a typical base engine may consume 0.85 gallons of fuel per hour during idle.25 The actual amount of fuel consumption varies among different engines and depends on the HVAC and electrical loads. A number of so-called “anti-idling” techniques have been introduced. The objective of these techniques is to avoid 23

use of the base engine during extended idle by substituting alternative sources of HVAC and electricity during rest stops. Some techniques involve installation and operation of on-board systems, while others require connecting the truck to a “shore-based” facility. 4.1.1 Best Practice 1-1: Off-Board Truck Stop Electrification Off-board truck stop electrification is a commercially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. This external system enables a truck driver to switch off the base engine by connecting the truck to a specially designed service module. This module provides heating, air conditioning and electricity to the truck cab, and it is installed temporarily through a window of the truck. This system is reported to consume less energy than the base engine and emits less CO2.26-29 A commercially available example of this is the IdleAire system.30 The projected 2025 modal GHG emissions are 721×106 tons of CO2 eq., and the potential reduction in modal GHG emissions are 2.4 ×106 tons of CO2 eq. Thus, the estimated potential reduction in modal GHG emissions are 0.3%. Trucks cannot use this alternative unless they are parked at a truck stop with this type of electrification system. 4.1.2 Best Practice 1-2: Truck-Board Truck Stop Electrification In contrast to Best Practice 1-1, which involves an external service module, truck stop electrification can be as simple as connecting the truck to a shore-based power supply via an electrical cable. This type of system is effective in situations where the HVAC system of the sleeper cab is entirely electrically operated and, thus, is independent of the base engine. This system is connected to the electrical grid. Thus, the energy use and emissions for this best practice are associated with those of the power grid. Compared to use of the base engine, this type of electrification is reported to consume less energy and emits less CO2.28-29,31 The estimated potential reduction in modal GHG emissions are 0.4%. Trucks cannot use this alternative unless they are parked at a truck stop with this type of electrification system. 4.1.3 Best Practice 1-3: Auxiliary Power Units Auxiliary power units (APUs) are commercially available systems that can avoid the need for idling of a truck’s base engine. An APU is installed on a truck and consists of a small diesel engine that provides power for an HVAC system and electrical outlets that service the sleeper cab. APUs are advertised as consuming less fuel under typical load conditions than the base engine. There are some practical questions regarding whether APUs are sufficiently quiet for use while a driver is sleeping, especially if they cycle on and off to meet intermittent A/C compressor demand, regarding their ability to rapidly cool-down the cab on very hot days, and 24

their actual fuel efficiency relative to base engines. Based on available information, APUs are estimated to consume less diesel fuel than the base engine and emit less CO2.27,32 The estimated potential reduction in modal GHG emissions are 2.1%. One disadvantage of this practice is its high capital cost. The capital cost of this practice may be even higher if it requires tailpipe emissions control devices. There is uncertainty regarding the real world relationship between fuel use rates of APUs compared to those of truck base engine, which confounds the ability to accurately estimate the fuel saving potential of this practice. 4.1.4 Best Practice 1-4: Direct-Fired Heaters Direct-fired heaters are commercially available systems for heating a sleeper cab by burning diesel fuel. Heat from combustion gases passes through a heat exchanger that warms the air inside the sleeper cab. In addition, these heater systems can be configured to provide heat for the base engine to maintain readiness for base engine restart in cold weather. Unlike the previous three best practices described above, this system is only applicable to heating in cold weather and does not provide cooling in hot weather. Furthermore, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. Direct-fired heaters are reported to consume less diesel fuel than the base diesel engines and to emit less CO2.27 The estimated potential reduction in modal GHG emissions are 1.1%. 4.1.5 Best Practice 1-5: Direct-Fired Heaters with Thermal Storage Units Thermal storage systems consist of a phase change material that can be heated or cooled from the truck cab air conditioning unit or heating system while the base engine is operating. These systems are demonstrated. The thermal storage system can be used as a means of providing warm or cool air to the sleeper cab via a heat exchanger and a blower unit when the base engine is off. In order to supplement the heating capability, thermal storage systems can be coupled with direct-fired heaters to store more thermal energy that is available for warming interior cabin air even when the direct-fired heater is not operating. This system supplies heating and cooling, but no electrical power, to the sleeper compartment when the base engine is off. Furthermore, similar to Best Practice 1-4, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. The combination of direct-fired heaters and thermal storage units is reported to consume less energy than the base diesel engines and to reduce CO2 emissions. The potential reduction in modal GHG emissions may be as large as 2.9%.27 The disadvantage of this practice is that it supplies no electricity, and requires power from the vehicle’s batteries.

25

4.2

Air Conditioning System Improvement

Mobile air conditioning systems cause "direct" and “indirect” GHG emissions. Direct GHG emissions are due to refrigerant leakage. Indirect GHG emissions are additional exhaust CO2 emissions that result from the engine load due to operation of the air conditioning system compressor. Refrigerant leakage rate reduction or use of low global-warming-potential (GWP) refrigerants can reduce direct emissions. Increasing the energy efficiency of air conditioning system can reduce indirect emissions. The estimates of potential reduction in modal GHG emissions for best practices within this subgroup are mainly based on a California governmental report.33 4.2.1

Best Practice 1-6: Enhanced Air Conditioning System I - for Direct Emissions Enhanced air conditioning systems, which are undergoing testing, can reduce direct GHG emissions by reducing the leakage rate of the commonly used HFC-134a refrigerant. The refrigerant leakage rates of these systems may be decreased through the use of low permeable hoses, improved hose ends and connectors, and improved compressor shaft seals.12,33-35 The estimated potential reductions in modal GHG emissions are 0.9%.33 There is not as yet a standard method for testing and certifying the leakage rate of an enhanced system is in the developmental stage. 4.2.2

Best Practice 1-7: Enhanced Air Conditioning System II - for Indirect Emissions Enhanced air conditioning systems for reducing indirect GHG emissions are commercially available. These systems can decrease base engine load requirements from mobile air conditioning systems by replacing fixed displacement compressors (FDCs) with externally controlled variable displacement compressors (VDC), using improved control systems, and using improved condensers and evaporators. By reducing the engine load requirements, exhaust CO2 emissions can be reduced.33,36-37 The benefit of reducing engine load is only available in hot weather when the A/C system is used. The estimated potential reductions in modal GHG emissions are 0.2%. 33 4.2.3 Best Practice 1-8: Alternative Refrigerants - CO2 The GWP of leaking refrigerant can be reduced by using an alternative low GWP refrigerant. The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas CO2 has GWP = 1. Therefore, CO2 is being investigated as an alternative refrigerant. This system 26

is in the developmental stage. Engineers are working to improve the reliability and efficiency of systems that use CO2 refrigerant.12,33-34,36 The estimated potential reductions in modal GHG emissions are 2.5%. 33 Safety assessment and potential risk mitigation may be needed because of different safety characteristics of this alternative refrigerant compared to HFC-134a. 4.2.4 Best Practice 1-9: Alternative Refrigerants - HFC-152a HFC-152a is another promising low GWP refrigerant. HFC-152a has a lower GWP (120) than that of HFC-134a. The transition from one HFC to another, such as from HFC-134a to HFC-152a, would be relatively easy (compared a transition to CO2) since these two refrigerants have similar properties and A/C system components would need less modification.26,27,42 The estimated potential reductions in modal GHG emissions are 2.4%.33 The flammability of this alternative refrigerant, although moderate, motivates the need for additional safety assessment and potential risk mitigation. 4.2.5 Best Practice 1-10: Alternative Refrigerants - HC Propane has been proposed as an alternative refrigerant for vehicle air conditioners. Propane has a lower GWP (20) than that of HFC-134a.38 This mobile hydrocarbon system has had more than 400,000 accumulated unit-years of operating experience in Australia. However, a propane-based refrigerant system uses more energy for operation and increases indirect GHG emissions, thus there is some trade-off.34 Furthermore, there is concern regarding its safety.36 If such systems are accepted for use in the U.S., the estimated potential reductions in modal GHG emissions are 2.5%. 33 The flammability of this alternative refrigerant motivates the need for additional safety assessment and potential risk mitigation. Release of propane to the atmosphere may also increase tropospheric ozone formation. 4.3

Aerodynamic Drag Reduction

Typical heavy-duty trucks need to use a significant portion of fuel to overcome aerodynamic drag. Since higher speed causes larger aerodynamic drag, the effect of aerodynamic drag on fuel economy is higher at highway speeds compared to local road speeds. Thus, reduction of aerodynamic drag may significantly improve the fuel efficiency of trucks, especially during highway speed operations.39 Aerodynamic drag can be significantly reduced by installing add-on devices to improve the vehicle profile, pneumatic blowing systems, and boat tail plates, or by improving vehicle load profile.

27

4.3.1

Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Truck tractor aerodynamic drag reduction options, including cab top deflector, sloping hood, and cab side flares, have been introduced into the market. These add-on devices are estimated to reduce the aerodynamic drag of medium- and heavy-duty trucks and increase their fuel efficiency and reduce GHG emissions.32 Taking into account that these devices reduce only a fraction of aerodynamic drag, the estimated potential reductions in modal GHG emissions are 1.4%. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account. 4.3.2

Best Practice 1-12: Vehicle Profile Improvement II - Closing and Covering of Gap between Cab and Trailer or Van, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Truck side and underside aerodynamic drag reduction options, including closing and covering the gap between a tractor and trailer (or van), aerodynamic bumper, underside air baffles, and wheel well covers, are commercially available technologies for medium- and heavy-duty trucks. Aerodynamic drag that results from the tractor-trailer gap can be reduced by installing gap covering add-on devices. Drag underneath the vehicle can be reduced by installing a lower bumper and underside air baffles. Wheel well covers enclose the open space between the wheels and the truck body, which streamlines the side of the truck. From the results of field tests, combining these options is estimated to reduce energy use and GHG emissions.11,32 The estimated potential reductions in modal GHG emissions are 2.4%. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account.

4.3.3

Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Truck trailer (or van) aerodynamic drag reduction options, including the improvement of their leading and trailing edge curvatures, are commercially available strategies. Aerodynamic drag can be reduced by the redesign of leading and trailing edges, such as rounded front corners and rounded aft corners.40 The estimated potential reductions in modal GHG emissions are 1.2%.32 4.3.4 Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction Pneumatic blowing systems are being tested as add-on devices that reduce aft-end 28

aerodynamic drag. This type of system blows air from slots at the rear of the trailers of heavy-duty vehicles in order to smooth air flow over the trailer surfaces and reduce aft-end aerodynamic drag. This results in reduction in vehicle fuel energy requirements. From the results of full-scaled tests, this system reduces energy use for an individual truck by 3.9% to 4.8%.32,41-42 However, based on the results of field tests, some truck configurations, such as the dimensions of the tractor-trailer gap, may inhibit the reduction of aerodynamic drag achievable via this system.43 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 2.2%. If used in combination with another best practice, such as Best Practice 1-12, there may be a negative synergistic effect in that the total improvement in aerodynamics is less than the linear sum of improvements from individual practices. 4.3.5 Best Practice 1-15: Planar Boat Tail Plates on a Tractor-Trailer Planar boat tail plates are being tested as add-on devices that reduce aft-end aerodynamic drag. These devices are rectangular plates mounted to the after-end of a trailer in an attempt to reduce the wake of trucks. The formation of a wake requires energy; thus, reducing the wake can energy consumption. From a full-scaled test for a tractor-van trailer, this practice significantly reduces aerodynamic drag, and it was found to reduce average energy use by approximately 8.3% over a 10,000 mile trip.44 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 3.8%. The drawback of this practice is that it may interfere with loading and unloading operations, depending on the design. 4.3.6 Best Practice 1-16: Vehicle Load Profile Improvement Aerodynamic drag can be reduced by the use of a streamlined load profile for a trailer, which is a low-tech option. This practice keeps the load profile of a trailer as low as possible and secures tarpaulins to smooth air flow and reduce energy use.11 The estimated potential reductions in modal GHG emissions are 0.4%. The drawback of this practice is that extra work for loading and unloading operations may be required. 4.4

Tire Rolling Resistance Improvement

Tire rolling resistance refers to a frictional effect associated with the contact of the tread of the tire with the road surface, and the flexing of the tread. Given that many trucks have a large number of tires in contact with the road (e.g., 18 wheels), this effect can be significant. Thus, rolling tire resistance is an important component of the total engine power demand on a 29

truck. Rolling resistance can be reduced by avoiding under-inflation of existing tires (to reduce unnecessary flexing), substituting one wide-tire for a pair of dual tires (leading to a net reduction in total tread area, sidewall flexing, or both), use of alternative tire materials to reduce rolling resistance, or use of pneumatic blowing. Each of these are discussed. To the extent that rolling resistance can be reduced, total engine power demand is also reduced. This, in turn, leads to reductions in fuel use and exhaust CO2 emission from the truck. 4.4.1 Best Practice 1-17: Automatic Tire Inflation Systems With properly inflated tires, tire rolling resistance is decreased and fuel use is reduced compared to under-inflation. Automatic tire inflation (ATI) systems are commercially available and are intended to keep vehicle tires properly inflated. These systems continually monitor and adjust the level of pressurized air in tires. The estimated potential reductions in modal GHG emissions are 0.6%.11,45 4.4.2 Best Practice 1-18: Wide-Base Tires Combination trucks usually have two sets of dual tires at each end of an axle. Dual tires are heavy and also produce high rolling resistance. Single wide-base tires, which are commercially available products, can replace these dual tires. Wide-base tires that have lower weight (e.g., there are only two sidewalls for one tire, versus four sidewalls for two tires) and produce lower rolling resistance reduce energy use. From the results of interstate field tests, using wide-base tires can increase fuel economy for a typical long-haul combination truck by 3%.11,32,46 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 2.0%. By using single instead of dual tires, there is a need for increased attention to tire inflation pressure for safety reasons. 4.4.3 Best Practice 1-19: Low-Rolling-Resistance Tires Compared to conventional tires, lower rolling resistance tires are commercially available from most tire companies, and trucks with these tires are more fuel-efficient because of the reduction of rolling resistance by the use of new materials, such as the combination of silica and synthetic elastomer.47 Based on the results of interstate field tests, using low-rolling-resistance tires can reduce energy use by 2.9%.32 Such tires could be used on any truck. Therefore, the estimated potential reduction in modal GHG emissions is 2.8%. The fuel saving advantage tends to be reduced when these low-resistance tires wear down.

30

4.4.4 Best Practice 1-20: Pneumatic Blowing to Reducing Rolling Resistance Pneumatic blowing is a technology under development that can reduce aerodynamic drag (Best Practice 1-14, Pneumatic Aerodynamic Drag Reduction) and tire rolling resistance. The system for Best Practice 1-14 can also blow streams of air under the truck. Since tire rolling resistance is directly proportional to loaded weight on the wheels times the tire friction coefficient, these air streams provide a slight lift that unloads the tires and reduces tire rolling resistance.48 Based on the results of full-scaled tests, this technology reduce energy use for a combination truck by 1.2% when accounting for the energy to compress and deliver pressurized air versus the benefits of reduced rolling resistance.32,42 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reductions in modal GHG emissions are 0.5%. However, this system may slightly increase dust pollution by dislodging particles on the road surface. 4.5

Hybrid Propulsion ― Best Practice 1-21: Hybrid trucks

Stop-and-go truck driving includes a fraction of idling conditions during which the truck base engine consumes fuel but produces no economically useful output (e.g., movement of goods, or repositioning of the truck to a new location). Hybrid propulsion systems, which are in the development stage for trucks, shut off the engine under idling conditions or situations of low engine power demand. They also recover or recycle energy from braking and deceleration. Trucks that have high fractions of stop-and-go freight transport activities within their driving cycles, such as medium-duty package and beverage delivery trucks, are good candidates for hybridization. Most heavy-duty trucks and a fraction of medium-duty trucks are long-haul trucks. Long-haul trucks have a lower proportion of short-term idling or low engine power demand in their duty cycles because of traffic conditions or frequency stops compared to medium-duty trucks in local services. Based on the results of hybridization effects modeling, medium-duty trucks in local service (e.g., delivery) can reduce energy use by 41.5%.20,49 This best practice is considered to be more suitable for medium duty trucks because of the characteristics of their duty cycles. Therefore, the estimated potential reductions in modal GHG emissions are 3.4%. The effect of additional weight associated with the battery set is accounted for in the estimates given here. A key disadvantage is the initial capital cost and uncertainty regarding the life of the battery pack and battery replacement costs. 4.6

Weight Reduction ― Best Practice 1-22:

Lightweight Materials

The energy consumed by a truck depends on many factors, including the tare weight of the vehicle itself. Substitution of light-weight materials for conventional materials (e.g., steel) 31

can reduce the total vehicle weight. High-strength, lightweight materials include aluminum, plastics, high strength steel alloys, and others. Since fuel use is directly proportional to truck weight, trimming 3,000 pounds (about 4% of truck weight) from a heavy-duty truck by using lighter-weight components improves fuel economy by 3%, and every 10% reduction in truck weight is estimated to reduce fuel use by 5 to 10%.50 In one study, mass reduction was estimated to reduce energy use by 4.8% or more.51 The estimated potential reductions in modal GHG emissions are 4.6%. However, current light-weight materials are costly and with no satisfied material characteristics. Further research and development for advanced materials are needed. 4.7

Transmission Improvement

Traditional truck transmissions are designed to provide discrete engine-wheel speed ratios. Transmission operation is associated with mechanical losses, leading to additional fuel consumption of the vehicle. Improving transmission systems, such as by using advanced high-efficiency transmission technologies and low-viscosity transmission lubricants, have the potential to reduce mechanical losses and reduce energy consumption.5,32 4.7.1 Best Practice 1-23: Advanced Transmission Advanced transmission technologies, such as the optimization of transmission engine-wheel speed ratios and reduction of mechanical losses, can reduce truck fuel use. A traditional transmission has a fixed number of gears that do not often achieve maximum efficiency. A continuously variable transmission (CVT) has belt-connected pulleys that can optimize transmission speed-load conditions and reduce fuel consumption. Mechanical losses in a transmission can be reduced by the reduction of gear surface roughness, the use of low-friction coatings, the use of new gear materials, and the use of a lock-up torque converter that eliminates slip at cruising speed. In one study, advanced transmission and improved lubricants were estimated to reduce energy use by 2%.51 Since improved transmission lubricants, which is described in Section 4.7.2, is estimated to reduce energy use by 1%,52 this practice is estimated to reduce fuel use by 1.0% on average for all conditions. The estimated potential reductions in modal GHG emissions are 1.0%. Driver training may be needed to avoid the confusion because the sound of the engine with traditional transmissions changes for acceleration operations but the sound of the engine with improved transmission does not change in the condition of acceleration.

32

4.7.2

Best Practice 1-24: Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Lubricants can reduce gear contact friction in transmissions, but they also reduce fuel efficiency because of their viscosity.53 Low-viscosity transmission fluid can be adopted to decrease transmission friction and also reduce fuel consumption. Assuming that all trucks can adopt low-viscosity transmission fluids, this practice is estimated to reduce energy use by approximately 1.0%.52 The estimated potential reductions in modal GHG emissions are 0.9%. Low-viscosity transmission fluid typically costs more than conventional lubricants. 4.8

Diesel Engine Improvement

The overall fuel efficiency of a diesel engine of a Class 8 trucks with a typical long-haul driving cycle is about 40%. The remaining 60% of fuel energy becomes waste heat. Some factors limit diesel engine efficiency, such as engine friction, peak cylinder pressure, combustion efficiency, and engine thermal management.53 Technologies that can improve the impacts of these factors can reduce fuel consumption significantly.5,32,51,53 4.8.1

Best Practice 1-25: Engine Friction Reduction through Low-Viscosity Engine Lubricants Some energy losses in an engine are because of mechanical friction. Reduction in internal engine friction can be achieved using improved lubricants. Low-viscosity engine lubricants are made from synthetic or mineral oil blends for the purpose of reducing internal engine friction. Low-viscosity engine lubricants can reduce energy use by 1.9%.32,52 The estimated potential reductions in modal GHG emissions are 1.8%. Low-viscosity engine fluid typically costs more than conventional lubricants.

4.8.2 Best Practice 1-26: Increased Peak Cylinder Pressures Diesel engine thermal efficiency is proportion to the peak pressures that can be achieved in the engine cylinders. However, the peak cylinder pressures are constrained by the strength and durability of the engine materials over the design service life of the engine. Measures that result in better materials that enable higher peak pressures can lead to higher engine efficiency.53-54 The development of new materials and associated new engine designs is an emerging area of work. This practice is commercially available and it is estimated to reduce energy use for heavy-duty trucks by 3.9%.51 Although this practice is likely to be applicable to all diesel engines in the long-run, its initial application is expected to focus on heavy-duty 33

trucks124

Therefore, the estimated potential reductions in modal GHG emissions are 3.1%.

4.8.3 Best Practice 1-27: Improved Fuel Injectors Incorrect fuel injection causes a reduction of combustion efficiency and an increase of emissions. The improvement of fuel injection via better control is expected to reduce truck fuel use. For example, advanced fuel injection systems, such as electronic unit injectors or common rail injectors with increased fuel injection pressure, are estimate to result in better control of the fuel injection rate and injection timing, and to produce finer vaporization of the fuel spray.32,51,54-55 The estimated potential reductions in modal GHG emissions are 5.5%. However, a drawback of higher injection pressures is the need to have stronger fuel-injection system and other engine components that withstand the higher pressures. The improved high pressure injectors may have leakage problem after a period of operation time. Regular diagnosis is needed to identify and address this problem. 4.8.4

Best Practice 1-28: Turbocharged, Direct Injection to Improved Thermal Management Turbocharging utilizes the exhaust air flow from engine to drive a turbine and then drive an air compressor to increase engine air intake. Advanced turbochargers that drive more air into the cylinder increase combustion efficiency and allow direct injectors to inject more fuel into cylinders. Most heavy-duty trucks have turbochargers, but medium-duty trucks do not. In one study, turbocharged, direct injection diesel engines was estimated to increase medium-duty truck fuel economy by 5 to 8%.51 Taking account that this practice is suitable for medium-duty trucks, the estimated potential reductions in modal GHG emissions are 0.8%. 4.8.5

Best Practice 1-29: Using Thermoelectric Technology to Recovery Waste Heat Overall engine thermal efficiency can be increased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Combining thermoelectric materials and advanced heat exchangers may recover waste heat in order to produce electricity. Based on the results of laboratory tests, a thermoelectric generator with a heat exchanger is projected to reduce energy use by 6.5%.56 The intended application of this best practice is for heavy duty trucks. The estimated potential reductions in modal GHG emissions are 5.2%.51 Thermoelectric converter technology needs further research and development (R & D) to increase its currently low conversion efficiency. The estimates reported here presume that such R & D will be successful. 34

4.9

Accessory Load Reduction

Truck auxiliary loads, such as the air-conditioning compressor, air compressor, fans, hydraulic pump, and coolant pump, are typically gear- or belt-driven and thus directly consume energy provided by the base engine. Full electrification of these mechanically driven auxiliaries can reduce engine load and use less energy.32 Using fuel cell units as the electricity source for electric auxiliaries can reduce more energy than using a generator to power electric auxiliaries.32,49 4.9.1 Best Practice 1-30: Electric Auxiliaries Most mechanical auxiliaries operate whenever truck base engines are running, which waste energy when the auxiliaries are not needed. The replacement of gear- or belt-driven auxiliaries by electrically driven systems can decouple mechanical loads from the base engine and reduce energy use. Since the average engine loads from mechanical auxiliaries are higher than those from a small generator that supplies electricity to electric auxiliaries, base engine fuel can be reduced. Based on a full-scale test of a prototype truck that used a small generator to produce electricity, full electrification of auxiliaries reduced fuel use by 2%.57 The estimated potential reductions in modal GHG emissions are 1.4%.32 The smaller generator for this practice may need pollution control devices in order to comply with future emissions standards. 4.9.2 Best Practice 1-31: Fuel-Cell-Operated Auxiliaries Fuel cells are an emerging technology for converting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is that they have substantially higher thermal efficiency. Among the barriers to practical use of fuel cells are the cost of precious materials used for their internal components and the need for conversion of readily available transportation fuels to a form that can be processed by the fuel cell. This best practice is based on the use of a small fuel cell sized to provide the requirements of all of the electrical auxiliaries, and is complementary to a base diesel engine used to supply the energy requirements of the power train. This best practice uses electrically-operated auxiliaries similar to those of Best Practice 1-30 (see Section 4.9.1). This system could be available in the market by 2012 with acceptable capital cost, according to some estimates.32,49 The estimated potential reductions in modal GHG emissions are 5.5%. This practice has high thermal efficiency, but further R & D is needed in order to reduce cost.

35

4.10

Modifications in Driver Operational Practice ―Best Practice 1-32: Truck Driver Training Program

The behavior of truck drivers can significantly impact fuel efficiency. For example, unnecessarily frequent shifting, rapid acceleration and stops and starts increase fuel use.58 Drivers can be encouraged to modify behaviors that unnecessarily increase fuel use via training programs that aim to convey better skills and habits. Furthermore, driver performance can be monitored and incentives can be provided to reward preferred behaviors. In one study, driver training and monitoring were estimated to reduce energy use by 3.8%.11 In several other studies in Europe and Canada, the effect of driver training, monitoring and incentive programs was estimated to increase fuel economy by 5 to 20%.11,58-59 Taking into account that a fraction of truck companies are likely to adopt these programs,11 the estimated potential reductions in modal GHG emissions are 3.1%. 4.11

Alternative Fuel ―Best Practice 1-33: B20 Biodiesel Fuel

An alternative fuel has the potential to reduce GHG emissions, although it may not lead to overall reductions in energy consumption. A fuel that is derived from renewable resources (e.g., biomass) can lead to reductions in the net amount of carbon dioxide released to the atmosphere. However, the substitution of one fuel for another leads to changes in emissions not only for the truck, but also for the entire fuel life cycle. Therefore, comparisons of different fuels must be done on a life cycle basis, which is the approach taken here. Some alternative fuels that have a lower ratio of carbon-to-hydrogen can also lead to reductions in the net amount of carbon dioxide released while trucks are operating. However, these fuels may not have reductions in the net amount of CO2 emissions on a life-cycle basis. For example, liquefied natural gas (LNG) contains less carbon per unit of heating value than diesel fuel, thereby reducing tailpipe CO2 emissions by approximately 15%. However, when fuel recovery, processing, transportation, and distribution are taken into account, the life-cycle CO2 emissions for LNG are estimated to increase by approximately 4% compared to that of petroleum diesel.60 For this reason, LNG is not further considered as a useful alternative fuel for purposes of GHG emissions reductions. However, if the fuel cycle emissions are reduced, then LNG could be reconsidered in the future. Biodiesel fuels are produced based on vegetable oils or animal fats that have been transesterized in order to achieve a viscosity similar to that of petroleum diesel. B100 refers to a biodiesel blend stock comprised of 100% vegetable or animal fat derived fuel. The carbon in B100 is essentially from renewable resources, depending on the configuration of the fuel production process. Thus, resultant CO2 emissions from combustion of biodiesel do not 36

contribute to a net increase in ambient CO2 concentrations, assuming that the amount of carbon sequestered to produce biofuels is equal to that emitted. However, under the current fuel infrastructure in the U.S., a significant portion of energy consumed in the production of biodiesel is based on consumption of petroleum diesel (e.g., for transport) or emissions associated with electrical energy consumption. Furthermore, B100 is not practical for direct use because of issues with handling. Instead, a more common approach is to use a blend of 20% blend stock and 80% petroleum diesel, referred to as B20. This blend has many of the handling advantages of petroleum diesel, while also offering some reduction in net CO2 emissions. The life-cycle CO2 emissions coefficient is estimated to decrease by 0.0069 tons CO2 eq. 6 per 10 BTU for B20 versus petroleum diesel. This alternative fuel is commercially available in limited amounts, but interest in biodiesel appears to be increasing. The estimated potential reductions in modal GHG emissions are 4.4%.61-64 The estimated potential modal increase in energy use from substitution of B20 for petroleum diesel is 4.3%.61 The potential disadvantages of biodiesel fuel depend on the percentage of blend stock used, the source of the blend stock, and whether the blend stock complies with the ASTM standard for B100. For B20 biodiesel based on a compliant B100 blend stock, the disadvantages to the vehicle operator are likely to be minor in warm climates, and include the need to replace and possibly enlarge the fuel filter and to manage fuel storage so as to avoid biofouling. In colder climates, there are potential problems with coagulation of biofuel because of its higher cloud point compared to petroleum diesel. However, the severity of this problem also depends on the percentage of blend stock used. Because biodiesel has a lower energy density than petroleum diesel, vehicle operators may experience a modest (approximately 5%) reduction in maximum power. 4.12

Summary of Potential Best Practices for the Truck Mode

All 33 potential best practices, sorted by 11 subgroups, for the truck mode are summarized in Table 4-1. They are in table format for the convenience of readers. 4.13

Comparisons of Modal GHG Emissions Reductions for the Best Practices

Figure 4-1 illustrates the variability among the potential best practices with respect to estimated reductions in modal GHG emissions. There percentage reductions in modal GHG emissions range from 0.2 to 5.5 percent when comparing individual best practices. However, these percentage reductions cannot be summed to obtain a total GHG emission reduction. Some best practices are mutually exclusive or have interactions with others. Furthermore, some practices may have substantial technical or 37

Table 4- 1. Subgroup

List and Description of Potential Best Practices for the Truck Mode. Type of Strategies

Technology

Technology Anti-Idling

Technology

Description 1-1. Off-Board Truck Stop Electrification Off-board truck stop electrification is a commercially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. This external system enables a truck driver to switch off the base engine by connecting the truck to a specially designed service module. This module provides heating, air conditioning and electricity to the truck cab, and it is installed temporarily through a window of the truck. This system is reported to consumes less energy than the base engines and emits less CO2.26-29 A commercially available example of this is the IdleAire system.30 The estimated potential reduction in modal GHG emissions is 0.3%. The operation charge for this system is approximately $1.25~$1.50 per hour per truck.5 1-2. Truck-Board Truck Stop Electrification Truck-board truck stop electrification, also called a shore power truck electrified parking system, is a commercially available system that can avoid the need for idling of the truck base engine while a truck is parked at a truck stop. In contrast to Best Practice 1-1, which involves an external service module, truck stop electrification can be as simple as connecting the truck to a shore-based power supply via an electrical cable. This type of system is effective in situations where the heating, ventilation and air conditioning (HVAC) system of the sleeper cab is entirely electrically operated and, thus, is independent of the base engine. This system enables a truck driver to switch off the base engine by connecting the truck to the electrical grid. Thus, the energy use and emissions for this best practice are associated with those of the power grid. Compared to use of the base engine, this type of electrification is reported to consume less energy and emits less CO2.28,29,31 The estimated potential reduction in modal GHG emissions is 0.4%. The operation charge for this system is $0.5~$1.00 per hour per truck.5 1-3. Auxiliary Power Units Auxiliary power units (APUs) are commercially available systems that can avoid the need for idling of a truck’s base engine wherever a truck driver parks for rest. An APU is installed externally on a truck and consists of a small diesel engine that provides power for an HVAC system and electrical outlets that service the sleeper cab. APUs are advertised as consuming less fuel under typical load conditions than the base engine. There are some practical questions regarding whether APUs are sufficiently quiet for use while a driver is sleeping, especially if they cycle on and off to meet intermittent A/C compressor demand, regarding their ability to rapidly cool-down the cab on very hot days, and their actual fuel efficiency relative to base engines. Based on available information, APUs are estimated to consume less diesel fuel than the base engine and emits less CO2.27,32 The estimated potential reduction in modal GHG emissions is 2.1%. The estimated incremental capital cost is $8,279.31

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Table 4-1. Continued Subgroup

Type of Strategies

Description

1-4. Direct-Fired Heaters Direct-fired heaters are commercially available systems for heating a sleeper cab by burning diesel fuel. Heat from combustion gases passes through a heat exchanger that warms the air inside the sleeper cab. In addition, these heater systems can be configured to provide heat for the base engine to maintain readiness for base engine restart in cold weather. Technology Unlike the previous three best practices described above, this system is only applicable to heating in cold weather and does not provide cooling in hot weather. Furthermore, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. Direct-fired heaters are reported to consume less diesel fuel than the base diesel engines and to emit less CO2. The estimated potential reduction in modal GHG emissions is 1.1%.27 1-5. Direct-Fired Heaters with Thermal Storage Units Direct-fired heaters are used to heat both the sleeper cab and engine when a truck is idling. Thermal storage systems consist of a phase Anti-Idling change material that can be heated or cooled from the truck cab air conditioning unit or heating system while the base engine is operating. These systems are demonstrated. The thermal storage system can be used as a means of providing warm or cool air via a heat exchanger and a blower unit to the sleeper cab for up to eight hours when the base engine is off. In order to supplement the heating capability, thermal storage Technology systems can be coupled with direct-fired heaters to store more thermal energy that is available for warming interior cabin air even when the direct-fired heater is not operating. This system supplies heating and cooling, but no electrical power, to the sleeper compartment when the base engine is off. Furthermore, similar to Best Practice 1-4, this system does not provide electrical power; instead, electrical power is drawn from the truck’s existing battery. The combination of direct-fired heaters and thermal storage units is reported to consume less energy than the base engines and to reduce CO2 emissions. The potential reduction in modal GHG emissions may be as large as 2.9%.27 1-6. Enhanced Air Conditioning System I - for Direct Emissions Direct GHG emissions of current HFC-134a mobile A/C systems are due to refrigerant leakage. Enhanced mobile A/C systems, which are undergoing testing, can reduce direct GHG emissions by reducing the leakage rate of the commonly used HFC-134a refrigerant. The refrigerant leakage Air rates of these system may be decreased through the use of low permeable conditioning improved hose ends and connectors, and improved compressor shaft Technology hoses,12,33-35 System HFC-134a emission from mobile A/C system is reported to seals. Improvement be approximately 8.5 g CO2 eq. per mile, including 6 g CO2 eq. per mile from direct leakage in normal operation conditions. Other emission is because of accidental release and dismantling emissions. Enhanced A/C systems are estimated to reduce direct leakage in normal operation conditions by 50%, which is about 3 g CO2 eq. per mile. The estimated potential reduction in modal GHG emissions is 0.9%.33



Type of Strategies

Description

1-7. Enhanced Air Conditioning System II - for Indirect Emissions Indirect GHG emissions of mobile A/C systems are additional exhaust CO2 emissions that result from the engine load due to operation of mobile A/C system. Mobile A/C systems operation time is about 34% of truck operation time. Based on the assessment results of a California government report that indirect emissions of running HFC-134a A/C systems are about 7.35 g CO2 eq. per mile, average indirect emissions are about 2.5 g CO2 eq. per mile in truck operation time. Enhanced A/C systems for reducing indirect GHG emissions are commercially available. These systems can decrease base engine load requirements from mobile A/C systems by replacing fixed displacement compressors (FDCs) with externally controlled variable displacement compressors (VDC), using improved control systems, and using improved condensers and evaporators. By reducing the engine load requirements, exhaust CO2 emissions for powering A/C system is reported to be reduced by 25%.33,36-37 The estimated potential reduction in modal GHG emissions is 0.2%. 1-8. Alternative Refrigerants - CO2 The GWP of leaking refrigerant can be reduced by using an alternative low Air GWP refrigerant. One of alternative low GWP refrigerant is CO2, which conditioning is called R744 while as a refrigerant. The current widely used refrigerant, System HFC-134a, has GWP = 1,300, whereas CO2 has GWP = 1. The Improvement Technology abundance of CO2 supply from many industries is also the advantage of this alternative refrigerant. Another advantage is that recovery and recycling of CO2 is not difficult. Vehicle industry is developing CO2-based air conditioning systems, and engineers are working to improve the reliability and efficiency of systems that use CO2 as refrigerant.12,33-34,36 The estimated potential reduction in modal GHG emissions is 2.5%.33 1-9. Alternative Refrigerants - HFC-152a 1,1-difluoroethane (C2H4F2), I is known as HFC-152a, is another promising low GWP refrigerant. HFC-152a has a lower GWP (120) than that of HFC-134a (1,300). The transition from one HFC to another, such as from HFC-134a to HFC-152a, would be relatively easy (compared a transition to CO2) since these two refrigerants have similar thermodynamic characteristics and A/C system components would need less modification. Technology However, its flammability causes additional safety considerations and the needs of risk mitigation approaches. For example, the evaporator may need to be located far from the passenger compartment. The design of the secondary heat exchange loop can enhance the safety of this system. HFC-152a systems is expected to be widely available within 4 years.12,33-34,36 The estimated potential reduction in modal GHG emissions is 2.4%.33

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40


Type of Strategies

Description

1-10.Alternative Refrigerants - HC Propane has been proposed as an alternative refrigerant for vehicle air conditioners. Propane is called R290 as an alternative refrigerant and has a lower GWP (20) than that of HFC-134a (1,300).38 This propane based refrigerant system has had more than 400,000 accumulated unit-years of operating experience in Australia. However, a propane based refrigerant Air system uses about 10% more energy for the operation of vehicle air conditioning Technology conditioners and increases indirect GHG emissions, thus there is some System tradeoff.34 Furthermore, there is concern regarding its safety because of Improvement the flammability of propane and the risk mitigation approaches are needed.36 The volatile organic compound properties of propane that increase tropospheric ozone formation is another concern.34,36,38 If such systems are accepted for use in the U.S., the estimated potential reduction in modal GHG emissions is 2.5%.33 1-11. Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Truck tractor aerodynamic drag reduction options, including cab top deflector, sloping hood, and cab side flares, have been introduced into the market. Cab deflectors are designed at the same height as the trailer. Flares or fairings on the side of cabs cover batteries, fuel tank and Technology suspension. These add-on devices are estimated to reduce the aerodynamic drag of medium- and heavy- duty trucks and increase their fuel efficiency by 2.0%. Taking into account that these devices reduce only a fraction of aerodynamic drag, the estimated potential reduction in modal GHG emissions is 1.4%. The estimated incremental capital cost is $750.32 1-12. Vehicle Profile Improvement II - Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Aerodynamic Baffles, and Wheel Well Covers Drag Truck side and underside aerodynamic drag reduction options, including Reduction closing and covering the gap between a tractor and trailer (or van), aerodynamic bumper, underside air baffles, and wheel well covers, are commercially available technologies for medium- and heavy-duty trucks. Aerodynamic drag that results from the tractor-trailer gap can be reduced by installing gap covering add-on devices, such as cab extenders, trailer Technology splitter plates, gap vortex stabilizer and gap seals. Drag underneath the vehicle can be reduced by installing lower bumper and underside air baffles. Wheel well covers enclose the open space between the wheels and the truck body, which streamlines the side of the truck. From the results of field tests, combining these options are estimated to reduce energy use and decrease GHG emissions.11,32 Taking into account that these devices reduce a fraction of aerodynamic drag, the estimated potential reduction in modal GHG emissions is 2.4%. The estimated incremental capital cost is approximately $1,500.32


41


Type of Strategies

Description

1-13. Vehicle Profile Improvement III - Trailer Leading and Trailing Edge Curvatures Truck trailer (or van) aerodynamic drag reduction options, including the improvement of their leading and trailing edge curvatures, are Technology commercially available strategies. Aerodynamic drag can be reduced by the redesign of leading edges and trailing edges of trailers or vans, such as rounded front corners and rounded aft corners.40 The estimated potential reduction in modal GHG emissions is 1.2%. The estimated incremental capital cost is $500.32,40 1-14 Pneumatic Aerodynamic Drag Reduction Pneumatic blowing systems are being tested as testing add-on devices that reduces aft-end aerodynamic drag. This type of system blows air from slots at the rear of the trailers of heavy-duty vehicles in order to smooth air flow over the trailer surfaces and reduce aft-end aerodynamic drag. This results in reduction in vehicle fuel energy requirements. From the results of full-scaled tests, this system reduces energy use for an individual truck Technology by 3.9% to 4.8%.32,41-42 However, based on the results of field tests, some truck configurations, such as the dimensions of the tractor-trailer gap, may inhibit the reduction of aerodynamic drag achievable via this system.43 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 2.2%. This system is Aerodynamic expected to be available in 2010 and the estimated incremental capital cost Drag is $2,500, but could be as high as $5,250.32,51 Reduction 1-15 Planar Boat Tail Plates on a Tractor-Trailer Planar boat tail plates are being tested as add-on devices that reduce aft-end aerodynamic drag. These devices are four rectangular plates mounted to the after-end of a trailer in an attempt to reduce the wake of trucks. The formation of a wake requires energy; thus, reducing the wake can energy consumption. To maintaining full-functional operation, rigid Technology composite sides with a flexible top and bottom are designed, and these plates can be folded. From a full-scaled test for a tractor-trailer, this practice was found to reduce average energy use by approximately 8.3% over a 10,000 mile trip.44 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 3.8%. 1-16. Vehicle Load Profile Improvement Aerodynamic drag can be reduced by the use of a streamlined load profile for a trailer, which is a low-tech option. This practice keeps the load profile of a trailer as low as possible and secures tarpaulins to smooth air Operation flow. For example, a suggested method for flatbed trailers is to arrange as low as possible and cover with a tarpaulin. A 2.4% energy reduction was reported for properly secured tarpaulins.11 Taking into account that it is suitable for combination trucks that have non-van trailers, the estimated potential reduction in modal GHG emissions is 0.4%.



Type of Strategies

Description

1-17. Automatic Tire Inflation Systems With properly inflated tires, tire rolling resistance is decreased and fuel use is reduced compared to under-inflation. Automatic tire inflation (ATI) systems are commercially available and are intended to keep vehicle tires properly inflated. These systems continually monitor and adjust the level Technology of pressurized air in tires. Installing ATI systems on a combination truck was reported to reduce 97 to 100 gallons of fuel per year, which is about 1.1 tons GHG emissions reduction per truck per year.11,45 The estimated potential reduction in modal GHG emissions is 0.6%. The estimated incremental capital cost is $900.5 1-18. Wide-Base Tires Combination trucks usually have two sets of dual tires at each end of an axle. Dual tires are heavy and also produce high rolling resistance. Single wide-base tires, which are commercially available products, can replace these dual tires on combination trucks. Wide-base tires that have lower weight (e.g., there are only two sidewalls for one tire, versus four sidewalls for two tires) and produce lower rolling resistance reduce energy use. From the results of field tests, wide-base tires increase fuel economy Technology Tire Rollin for a typical long-haul combination truck by 3.0% compared to equivalent Resistance dual tires.11,32,46 This best practice is suitable for combination trucks that Improvement have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 2.0%. New trucks with wide-base tires are possibly cheaper than with dual tires, but retrofitting existing trucks have higher cost. Averagely, the estimated incremental capital cost is $700.32 Increasing the frequency of monitoring tire pressure is probably needed for adopting wide-base tires. 1-19. Low-Rolling-Resistance Tires Conventional tires have high rolling resistance that increases energy use. Low-rolling-resistance tires are commercially available from most tire companies. Trucks with low-rolling resistance tires are more fuel-efficient because of the reduction of tire rolling resistance by the use of new materials, such as the combination of silica and synthetic Technology elastomer.47 Based on the results of interstate field tests, using low-rolling-resistance tires can reduce rolling resistance that reduce energy use by 2.9%.32 Such tires could be used on any truck. Therefore, the estimated potential reduction in modal GHG emissions is 2.8%. The estimated incremental capital cost is $550. The requirements for higher inflation pressure and high monitoring frequency may limit the extent of their market penetration.


43


Type of Strategies

Description

1-20 Pneumatic Blowing to Reducing Rolling Resistance Pneumatic blowing is a technology under development that can reduce aerodynamic drag, which is discussed in Best Practice 1-14: Pneumatic Aerodynamic Drag Reduction, and tire rolling resistance. The system for Best Practice 1-14 that is used for aerodynamic drag reduction, including compressor, piping, and blow control, can also be used to blow streams of air under trucks. Additional pipes, jets, valves, selective blowing, and control system may be needed to blow air under trucks. Since tire rolling resistance is directly proportional to loaded weight on the wheels times the tire friction coefficient, these air streams provide a slight lift that unloads Tire Rollin Resistance Technology the tires and reduces tire rolling resistance.48 Based on the results of full-scaled tests, this technology reduce energy use for a combination truck Improvement by 1.19% when accounting for the energy to compress and deliver pressurized air versus the benefits of reduced rolling resistance.32,42 This best practice is suitable for combination trucks that have van trailers, which are a portion of the total truck fleet. Therefore, the estimated potential reduction in modal GHG emissions is 0.5%. If the pneumatic blowing system for reducing aerodynamic drag has been installed on a combination truck, additional $500 capital cost for extra components would be needed.32 This technology is estimated to be available in 2015 for combination trucks.51 1-21. Hybrid Trucks Stop-and-go truck driving includes a significant fraction of idling conditions during which the truck base engine consumes fuel but produces no economically useful output (e.g., movement of goods, or repositioning of the truck to a new location). Hybrid propulsion systems, which are in the development stage for trucks, shut off the engine under idling conditions or situations of low engine power demand. They recover or recycle energy from braking or deceleration. Fuel use reduction potential of hybrid trucks is sensitive to their duty cycles. Trucks that have high fractions stop-and-go freight transport activities within their driving cycles, such as medium-duty package and beverage delivery trucks, are good candidates for hybridization. Most of heavy-duty trucks and a fraction of Hybrid Propulsion Technology medium-duty trucks are long-haul trucks. Long-haul trucks are not considered as good candidates because these trucks have a lower proportion of short-term idling or low engine power demand in their duty cycles because of traffic conditions or frequency stops compared to medium-duty trucks in local services. Based on the results of hybridization effects modeling, medium-duty trucks in local service (e.g., delivery) can reduce energy use by 41.5%.20,49 This best practice is considered to be more suitable for medium duty trucks because of the characteristics of their duty cycles. Therefore, t he estimated potential reduction in modal GHG emissions is 3.4%. Experts in a study estimated that this technology would be available in 2010.51,65 The estimated 2005 incremental capital cost is approximately $7,100, and the estimated 2025 incremental capital cost is expected to drop to approximately $3,100.49



Type of Strategies

Description

1-22. Lightweight Materials The energy consumed by a truck depends on many factors, including the tare weight of the vehicle itself. Substitution of light-weight materials for conventional materials (e.g., steel) can reduce the total vehicle weight. High-strength, lightweight materials include aluminum, plastics, and others. Since fuel use is directly proportional to truck weight, trimming Weight Technology 3,000 pounds (about 4% of truck weight) from a heavy-duty truck by using Reduction lighter-weight components improves fuel economy by 3%, and every 10% reduction in truck weight is estimated to reduce fuel use by 5 to 10%.50 In one study, mass reduction was estimated to reduce energy use by 4.6% or more.51 The estimated potential reductions in modal GHG emissions are 4.8% or more. The estimated incremental capital cost is $2,000. 1-23. Advanced Transmission Advanced transmission technologies, such as the optimization of engine-wheel speed ratios and reduction of mechanical losses in a transmission system can reduce truck fuel consumption. A traditional transmission has a fixed number of metal gears to provide several discrete speed ratios that do not often achieve maximum efficiency and increase fuel use. A continuously variable transmission (CVT) has belt-connected pulleys that provide an uninterrupted range of engine-wheel speed ratios to optimize transmission speed-load conditions and reduce fuel use. Adopting CVT for heavy-duty trucks needs new materials to withstand the high torque loads. Mechanical losses in a transmission, such as gear Technology contact friction, can be reduced by the reduction of gear surface roughness, the use of low-friction coatings, the use of new gear materials, and the use of a lock-up torque converter (a mechanical clutch locking the torque converter impeller and turbine together to eliminate slip at cruising speed). In one study, advanced transmission and improved lubricants were Transmission estimated to reduce energy use by 2%.51 Since improved transmission Improvement lubricants, which is described in Section 4.7.2, is estimated to reduce energy use by 1%,52 this practice is estimated to reduce fuel use by 1.0% on average for all conditions. The estimated potential reductions in modal GHG emissions are 1.0%. This practice is ready introduced into market and the estimated incremental capital cost is $1,000.32 . 1-24.Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Lubricants can reduce gear contact friction in transmission, but they also reduce fuel efficiency because of their viscosity.53 Low-viscosity transmission fluid, made from synthetic or mineral oil blends, are reported Technology to decrease transmission friction and also reduce fuel consumption. Assuming that all trucks can adopt low-viscosity transmission fluids, this practice is estimated to reduce energy use by 1% or more.52 The estimated potential reductions in modal GHG emissions are 0.9%. This practice is commercially available and the estimated incremental capital cost is $500.11,51



Type of Strategies

Description

1-25.Engine Friction Reduction through Low-Viscosity Engine Lubricants Some energy losses in an engine are because of mechanical friction. Reduction in internal engine friction can be achieved using improved lubricants. Low-viscosity engine lubricants are made from synthetic or Technology mineral oil blends for the purpose of reducing internal engine friction. Low-viscosity engine lubricants can reduce energy use by 1.86% or more.32,52 The estimated potential reductions in modal GHG emissions are 1.8%. This practice has commercially available products and the estimated incremental capital cost is $500.11,51 1-26. Increased Peak Cylinder Pressures Diesel engine thermal efficiency is proportion to the peak pressures that can be achieved in the engine cylinders. However, the peak cylinder pressures are constrained by the strength and durability of the engine materials over the design service life of the engine. Measures that result in better materials that enable higher peak pressures can lead to higher engine efficiency.53,54 The development of new materials and associated Technology new engine designs is an emerging area of work. This practice is commercially available and it is estimated to reduce energy use for heavy-duty trucks by 3.9%.51 Although this practice is likely to be Diesel Engine applicable to all diesel engines in the long-run, its initial application is Improvement expected to focus on heavy-duty trucks Therefore, the estimated potential reductions in modal GHG emissions are 3.1%. The incremental capital cost is $1,000. 1-27. Improved Fuel Injectors Incorrect fuel injection causes a reduction of combustion efficiency and an increase of emissions. The improvement of fuel injection, such as a better control of the fuel injection rate and injection timing, and the production of finer vaporization of the fuel spray, is expected to reduce truck fuel use. The developments of advanced fuel injection systems, such as electronic unit injectors, common rail injectors, electronic unit pump, and electronic distribution pump, can improve fuel injection and reduce fuel use. For Technology example, common rail injectors with electronic control use high-pressure pump to compress fuel into high-pressure accumulation chamber (Rail), and the pressure of fuel inside remains constant. Since high-pressure fuel is always available for injection, electronic injectors can easily optimize fuel injection rate and time, and improves fuel atomization and dispersal. Maximizing fuel injection pressure can also enhance fuel reduction by improving fuel vaporization and dispersal in the cylinder. 32,51,54-55 The estimated potential reductions in modal GHG emissions are 5.5%. The estimated incremental capital cost is $1,500.


46


Type of Strategies

Description 1-28. Turbocharged, Direct Injection to Improved Thermal Management Diesel engine power is proportional to air intake and fuel.

Turbocharging utilizes the exhaust air flow from engine to drive a turbine and then drive an air compressor to increase engine air intake. Advanced turbochargers that drive more air in the cylinder increase combustion efficiency and allow direct injectors to inject more Technology fuel into cylinders. Most heavy-duty trucks have turbochargers, but medium-duty trucks do not. In one study, turbocharged, direct injection diesel engines was estimated to increase medium-duty truck fuel economy by 5 to 8%.22,51 Taking account that this practice is suitable for medium-duty trucks, the estimated potential reductions in modal GHG emissions are 0.8%. This practice is already commercially available, and the estimated incremental capital cost is $700-1,000.51 Diesel Engine 1-29. Thermoelectric Technology to Recovery Waste Heat Improvement Overall engine thermal efficiency can be increased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Laboratory tests indicate that a small-scaled 5.54 kW thermoelectric generator can increase fuel economy by 2.2 to Technology 4.4%. Combining thermoelectric materials and heat exchangers may recovery waste heat in order to produce electricity. Based on the results of laboratory tests, a thermoelectric generator with a heat exchanger is projected to reduce energy use by 6.5%.56 The intended application of this best practice is for heavy duty trucks.51 The estimated potential reductions in modal GHG emissions are 5.2%. Those studies estimated that this technology would be introduced in 2010 and the estimated incremental capital cost is $2,000.51 1-30. Electric Auxiliaries Truck auxiliaries, such as air-conditioning compressor, air compressor, fans, hydraulic pump, and coolant pump, are gear- or belt-driven by truck base engine. Mechanical auxiliaries operate whenever base engines are running, which waste energy when the auxiliaries are not needed. The replacement of mechanical auxiliaries by electrically driven systems can decouple mechanical loads from the base engine and reduce energy use. Accessory Since the average engine loads from mechanical auxiliaries are higher than Load Technology those from a small generator that supplies electricity to electric auxiliaries, Reduction base engine fuel can be reduced. Based on a full-scaled test of a prototype truck that used a small generator to produce electricity, full electrification of auxiliaries reduces fuel use by 2%.57 The estimated potential reductions in modal GHG emissions are 1.4%.32,51 The estimated incremental capital cost is $500. The additional small generator can also supply electricity for trucks to avoid extended idling, which is discussed in Best Practices 1-3, “Auxiliary Power Units.”



Type of Strategies

Description

1-31. Fuel-Cell-Operated Auxiliaries Fuel cells are an emerging technology for converting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is that they have substantially higher thermal efficiency. Among the barriers to practical use of fuel cells are the cost of precious materials used for their internal components and the need for conversion of readily available transportation fuels to a form that Accessory can be processed by the fuel cell. This best practice is based on the use of Load Technology a small fuel cell sized to provide the requirements of all of the electrical Reduction auxiliaries, and is complementary to a base diesel engine used to supply the energy requirements of the power train. This best practice uses electrically-operated auxiliaries similar to those of Best Practice 1-30 (see Section 4.9.1). This system could be available in the market by 2012 with acceptable capital cost, according to some estimates.32,49 The estimated potential reductions in modal GHG emissions are 5.5%. The estimated incremental capital cost is $500.32,49 1-32. Truck Driver Training Program The behavior of truck drivers can significantly impact fuel efficiency. For example, unnecessarily frequent shifting, rapid acceleration and stops and starts increase fuel use.58 Drivers can be encouraged to modify behaviors that unnecessarily increase fuel use via training programs that aim to convey better skills and habits. For example, drivers can learn to improve their operation skills, such as acceleration and shifting technique. These programs can also change driving behaviors, such as route choice and unnecessary idling time. Furthermore, driver performance can be Modifications monitored and incentives can be provided to reward preferred behaviors. in Driver Operation In one study, driver training and monitoring were estimated to reduce Operational energy use by 3.8%.11 In several other studies in Europe and Canada, the Practice effect of driver training, monitoring and incentive programs was estimated to increase fuel economy by 5 to 20%.11,58-59 For example, a truck fleet company has reduce energy use by 19% by supplying fuel-saving information, using a driver incentive program and regularly reviewing engine printouts.59 Some other best practices, such as anti-idling practices, may inhibit the reduction of energy use for truck driver training program. Taking into account that only a fraction of truck companies are likely to adopt these programs,11 the estimated potential reductions in modal GHG emissions are 3.1%.


48

Table 4-1. Continued Type of Strategies

Subgroup

Description

1-33. B20 Biodiesel Fuel for Trucks Biodiesel fuels are produced based on vegetable oils or animal fats that have been transesterized in order to achieve a viscosity similar to that of petroleum diesel. The potential market share of B20 biodiesel is estimated as 51.2% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and Technology the distribution ratio among the truck, rail and water modes.63-64 The estimated potential reductions in modal GHG emissions are 4.4%.61-64 Based on life cycle inventories, the production of alternative fuels consumes more energy than the production of petroleum diesel. For example, processes for producing biodiesel, such as soybean crushing and soy oil conversion, are energy intensive.66 The estimated potential modal increase in energy use is 4.3%.61

Alternative Fuel

Modal GHG Emissions Reductions (%)

6 5 4 3 2 1 0 1

3

5

7

9

11 13 15 17 19 21 23 25 27 29 31 33

Best Practice Number for the Truck Mode (1 refers to Best Practice 1-1, 2 refers to Best Practice 1-2, and so on) Figure 4- 1.

Reductions in Modal GHG Emissions for the Best Practices for the Truck Mode

49

practical barriers to their acceptance, as described previously. 4.14

Quantitative Cost Results for Selected Best Practices

Quantitative cost results for the best practices for which sufficient information was available to perform such assessments are summarized in standardized reporting tables, which are given in Appendix A. In contrast, assessment results for the best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix A. To date, there is sufficient information for five best practices upon which to make quantitative assessments. The other 29 best practices are assessed qualitatively. The best practices assessed quantitatively include off-board truck stop electrification, auxiliary power units, direct-fired heaters, hybrid trucks, and B20 biodiesel. Table 4-2 summarizes the quantitative assessment results of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for these five selected best practices. Four of these five best practices produce net cost savings. These savings are the net result of substantial costs offset by substantial savings based on reduced energy usage. For one of the best practices, biodiesel, the net saving is negative, indicating that this practice do not pay for themselves. Its fuel cost is higher than that for petroleum diesel (based on current typical experience) and thus there is a net increase in total costs. Overall, there is substantial variability in the cost-effectiveness of these best practices when net cost savings are normalized based on the GHG emissions reductions. Direct-fired heater appears to be the most cost-effective, whereas the use of B20 biodiesel appears to be the least cost effective. However, the APU, hybrid, and biodiesel practices have the potential to achieve substantially larger magnitudes of GHG emissions reductions than the other two options. Off-board truck-stop electrification could only contribute small magnitude of GHG emissions reductions because 80% of truck idling is not at truck stops. Direct-fired heaters can be only used in cold weather; therefore, this restriction limits their potential for GHG emissions reductions and energy reduction.

50

Table 4- 2.

a

b c d

Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Truck Modea

Best Practice Number

1-1

1-3

1-4

1-21

1-34

Name

Off-Board Truck Stop Electrification

Auxiliary Power Units

Direct-Fired Heaters

Hybrid Trucks

B20 Biodiesel

Subgroup

Anti-idling

Anti-idling

Anti-idling

Responsible Parties

1, 2, 5, 13, 20, 21, 22

1, 2, 5, 6, 8, 11

1, 2, 5

1, 2, 6, 8 CO2 Technology C



Hybrid Propulsion 1, 2, 4, 5, 6, 8, 9, 12, 16, 18, 19, 20, 21, 22 1, 2, 4, 6, 7 CO2 Technology N

Alternative Fuel 1, 2, 4, 5, 6, 12, 14, 16, 18, 19, 20, 21, 22 1, 2, 4, 5, 6, 7 CO2 Technology C

2.4

15.0

7.6

24.5

30.8

27

185

94

300

-370.0

570

3,000

390

2430

3,300

900

3,400

1,740

5,600

0

330

440

1,350

3,190

-3,300

138

29

178

130

-108

12

2.3

14

10.6

N/A b

N/A c

3.2

0.6

2.1

N/A d

Target Parties Target GHGs Strategy Types Developmental Status Modal GHG Emission Reduction (106 ton CO2 eq./year) Modal Energy Use Reduction (1012 BTU/year) Annualized Costs ($ 106/year) Annual Energy Cost Saving ($ 106/year) Net Saving ($ 106/year) Net Saving per Unit of GHG Emissions Reductions ($/ton CO2 eq.) Net Saving per Unit of Energy Use Reduction ($/ton CO2 eq.) Simple Pay-back Period (years)

These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. Cost results are presented only for those best practices for which adequate data were available. This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. There is no pay-back period for this best practice because there is no initial capital cost to uses. There is no pay-back period for this best practice because there is no net saving.

51

5.0.

BEST PRACTICES FOR THE RAIL MODE

This chapter identified and characterizes six potential best practices applicable to the rail mode. These best practices are divided into four subgroups, including anti-idling, weight reduction, rolling resistance improvement, and alternative fuel. Additional details regarding these best practices are in Appendix B. For four of these best practices, sufficient data were available to quantify costs. 5.1

Anti-Idling

Line-haul locomotives and switchers are often idled for long periods of time to heat or cool the cab and to avoid the difficulty of restarting the engine. Over half (55%) of long-haul locomotive operation time and approximately 75% of switcher operation time are at idle.67 During idling, a typical locomotive consumes approximately 3 gallons of fuel per hour.67-68 Anti-idling technology can reduce long-duration locomotive idling, which in turn reduces fuel use and greenhouse gas emissions. 5.1.1

Best Practice 2-1: Combined Diesel Powered Heating and Auto Engine Start/Stop Systems A diesel powered heating system can keep the engine block temperature above 100 oF. Such systems utilize waste heat from a small diesel engine to heat the main engine and to generate electricity using by an alternator. An auto engine start/stop system can shutdown and restart both long-haul and switching locomotive engines automatically, based on a preprogrammed set of values (e.g., water and coolant temperature, battery voltage, and air brake cylinder pressure).69 For example, a driver can set the system to the restart engine and turn on heat when the ambient temperature falls below 65° F.70 Both of these systems can be used simultaneously to shut down the engine when not needed while also keep the engine warm in preparation for a restart and while maintaining batteries in a ready status. This practice, which includes both of these systems, can reduce locomotive energy use at idling by approximately 80%.67 This practice has been demonstrated in terms of installation on a locomotive and realization of reduced idling.68 Based on the results of field tests, this practice was found to reduce overall long-haul idling time by 70% and overall switcher idling time by 80%.67-68 The estimated potential reductions in modal GHG emissions and energy use are both 3.6%.

52

5.1.2 Best Practice 2-2: Battery-Diesel Hybrid Switching Locomotive Battery-diesel hybrid switchers are commercially available locomotives that can replace traditional switching locomotives. Traditional switchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 125 to 300 hp) and large (60,000 lbs) lead-acid batteries. This small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomotive non-use. At full load, the batteries account for 95% of the horsepower and the small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/stop system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteries are fully charged based on battery voltage values. From the results of field tests, a battery-diesel hybrid switcher was found to reduce daily fuel use by 35 to 57%.71 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reductions in modal GHG emissions and energy use are both 1.8%. The drawback of this practice is that only yard switchers can apply this practice. 5.1.3 Best Practice 2-3: Plug-In Units Plug-in units are commercially available systems that can avoid the need for idling of switcher engines while switchers are parked in switching yards. These systems, which require both on-board and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomotive into an external electrical power source. These systems can use electricity powered systems to supply heat, circulate and heat coolant and oil, and keep batteries charged. The use of a plug-in unit with a switching locomotive is estimated to consume 14% less energy than without a plug-in unit, when taking into account avoided direct diesel fuel use for operating the locomotive and production of electricity for the external power supply.72 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.4%, respectively. The drawback of this practice is that only yard switchers can apply this practice at appropriately equipped locations. 5.2

Weight Reduction ― Best Practice 2-4:


The use of lighter-weight components to reduce the weight of locomotives and railcars has the potential to reduce fuel use. High-strength, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. For example, newly designed coil steel cars have lighter tare weight and extra carrying capacity. Redesigned railcars for hauling steel slabs, which are lighter than conventional railcars, can carry 53

more goods and also reduce energy use. Higher-capacity railcars that have better design and that use lightweight materials were introduced by Canadian Pacific Railway.73-74 Based on a Canadian study, light-weight coal cars are estimated to reduce energy use by 10 percent, and light-weight grain cars are estimated to reduce energy use by 5 percent. The estimated potential reductions in modal GHG emissions and energy use are both 4.8%. However, current light-weight materials may be costly and may not have satisfactory material characteristics, such as strength. Further research and development for advanced materials is needed. 5.3

Rolling Resistance Improvement ― Best Practice 2-5: Lubrication Improvement

Some energy expended by the locomotive is lost to wheel-to-rail friction. Reductions in wheel-to-rail resistance can be made via improved lubrication. Efficient lubrication systems, such as top-of-rail lubrication systems, reduce wheel and rail wear and reduce fuel consumption. These systems can avoid wheel slippage by distributing a proper amount of lubricants on the rail, so as to reduce wheel-to-rail resistance without causing slippage.75 Based on the results of field tests, this practice can reduce fuel consumption by 4% to 6%.76-77 The estimated potential reductions in modal GHG emissions and energy use are both 4.0%. 5.4

Alternative Fuel ― Best Practice 2-6:


B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for diesel locomotives. Based on a life cycle analysis, the CO2 emissions are estimated to decrease by 0.0069 tons CO2 eq. per 106 BTU for B20 compared to petroleum diesel. The estimated potential reduction in modal GHG emissions is 5.5%.61,63-64,78-79 Based on life cycle inventories, the production of biodiesel consumes more energy than the production of petroleum diesel.66 The estimated potential modal increase in energy use is 5.3%.61 . 5.5

Summary of Potential Best Practices for the Rail Mode

The six potential best practices for the rail mode are summarized in Table 5-1. in table format for the convenience of readers. 5.6

They are

Comparisons of the Modal GHG Emissions Reductions for the Best Practices

Figure 5-1 illustrates the variability among the potential best practices with respect to estimated reductions in modal GHG emissions. Some best practices are mutually exclusive or have interactions with others. Thus, these percentage reductions cannot be summed to obtain a total aggregated emission reduction. 54


Anti-Idling

List and Description of Potential Best Practices for the Rail Mode

Type of Strategies

Description

2-1. Combined Diesel Powered Heating System and Auto Engine Start/stop System A small diesel powered heating system can keep the engine block temperature above 100 oF. Such systems utilize waste heat from a small diesel engine to heat the main engine and to generate electricity using by an alternator. An auto engine start/stop system can shutdown and restart both long-haul and switching locomotive engines automatically, based on a preprogrammed set of values (e.g., throttle position, water and coolant temperature, battery voltage, and air brake cylinder pressure), by using a microprocessor.69 For example, a driver can set the system to the restart engine and turn on heat when the ambient temperature falls below 65° F.70 Technology Both of these systems can be used simultaneously to shut down the engine when not needed while also keep the engine warm in preparation for a restart and while maintaining batteries in a ready status. This practice, which includes both of these systems, can reduce locomotive energy use at idling by approximately 80%.67 This practice has been demonstrated in terms of installation on a locomotive and realization of reduced idling.16 Based on the results of field tests, this practice was found to reduce overall long-haul idling time by 70% and overall switcher idling time by 80%.67-68 The estimated potential reduction in modal GHG emissions and energy use are both 3.6%. The estimated incremental capital cost is $28,000 for diesel powered heating system and $7,500 for auto engine start stop system.68 2-2. Battery-Diesel Hybrid Switching Locomotive Battery-diesel hybrid switchers are commercially available locomotives that can replace traditional switching locomotives. Traditional switchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 125 to 300 hp) and large (60,000 lbs) lead-acid batteries. The lifetime of these Pb-acid batteries are expected to be 10–15 years.69,72 The small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomotive non-use. At full load, the batteries account for 95% of the horsepower and Technology the small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/stop system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteries are fully charged based on battery voltage values.71 From the results of field tests, a battery-diesel hybrid switcher was found to reduce daily fuel use by 35 to 57%.71 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reduction in modal GHG emissions is 1.8%. The estimated capital cost is $200,000.


55


Type of Strategies

Description

2-3. Plug-In Units Plug-in units are commercially available rail yard electrification systems that can avoid the need for idling of switcher engines while switchers are parked in switching yards. These systems, which require both on-board and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomotive into an external power source of three-phase AC. These systems can use electricity powered systems to supply heat, circulate and heat coolant and oil, and keep batteries charged. Anti-Idling Technology They are only available at specific locations, such as switching yard. The use of a plug-in unit with a switching locomotive is estimated to consume 14% less energy than without a plug-in unit, when taking into account avoided direct diesel fuel use for operating the locomotive and production of electricity for the external power supply.72 Since switching locomotives are responsible for only a small portion (5%) of total rail fuel use, the estimated potential reduction in modal GHG emissions and energy use are 0.6% and 0.4%, respectively. The estimated capital cost is $8,000. 2-4. Lightweight Materials The use of lighter-weight components to reduce the weight of locomotives and railcars has the potential to reduce fuel use. High-strength, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. For example, newly designed coil steel cars have lighter tare weight by up to 55,200 pounds and extra carrying capacity. Redesigned railcars for Weight Technology hauling steel slabs, which are lighter than conventional railcars by 20,000 Reduction pounds, can carry more goods and also reduce energy use. Higher-capacity railcars that have better design and that use lightweight materials were introduced by Canadian Pacific Railway.73-74 Based on a Canadian study, light-weight coal cars are estimated to reduce energy use by 10 percent, and light-weight grain cars are estimated to reduce energy use by 5 percent. The estimated potential reduction in modal GHG emissions is 4.8% or more. 2-5. Lubrication Improvement Some energy expended by the locomotive is lost to wheel-to-rail friction. Reductions in wheel-to-rail resistance can be made via improved lubrication. Efficient lubrication systems, such as top-of-rail lubrication Rolling systems, reduce wheel and rail wear and reduce fuel consumption. These Resistance Technology systems can avoid wheel slippage by distributing a proper amount of Improvement lubricants on the rail, so as to reduce wheel-to-rail resistance without causing slippage.75 Based on the results of field tests, this practice can reduce fuel consumption by 4% to 6%, depending on the grade and curvature.76-77 The estimated potential reduction in modal GHG emissions and energy use are both 4.0%.


56

Table 5-1. Continued Type of Strategies

Subgroup

Description 2-6. B20 Biodiesel Fuel for Locomotives

B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for diesel locomotives. Based on a life cycle analysis, the CO2 emissions are estimated to decrease by 0.0069 tons CO2

Alternative Fuel

eq. per 106 BTU for B20 compared to petroleum diesel.61 Although this alternative fuel has been a commercially available product for trucks, it is being tested for the suitability for the use as locomotive fuel. The Technology potential market share of B20 biodiesel is estimated as 64% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes.63-64 The estimated potential reduction in modal GHG emissions is 5.5%.61,63-64,78-79 Based on life cycle inventories, the production of biodiesel consumes more energy than the production of petroleum diesel.66 The estimated potential modal increase in energy use is 5.3%.61


6 5 4 3 2 1 0 2-1

2-2

2-3

2-4

2-5

2-6

Best Practice Number for the Rail Mode Figure 5- 1.

Reductions in Modal GHG Emissions for the Best Practices for the Rail Mode

57

The percentage reductions in modal GHG emissions range from 0.6 to 5.5 percent when comparing individual best practices. Some best practices are mutually exclusive or have interactions with others. Thus, these percentage reductions cannot be summed to obtain a total aggregated emission reduction. 5.7

Quantitative Cost Results for the Selected Best Practices

Quantitative cost results for the best practices with sufficient information are summarized in individualized standardized reporting tables, which are given in Appendix B. In contrast, assessment results for the best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix B. To date, there is sufficient information for four best practices upon which to make quantitative assessments. The other three best practices are assessed qualitatively. The best practices assessed quantitatively include combined diesel powered heating and start/stop system, battery-diesel hybrid switching locomotive, plug-in units, and B20 biodiesel. Table 5-2 summarizes the quantitative assessment results of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for these four selected best practices. Three of these four best practices produce net cost savings. These savings are the net result of substantial costs offset by substantial savings based on reduced energy usage. For one of the best practices, B20 biodiesel, the net savings are negative, indicating that these practices do not pay for themselves. It is because that B20 biodiesel fuel cost is higher than that for petroleum diesel (based on current typical experience) and thus there is a net increase in total costs. When net cost savings are normalized based on the GHG emissions reductions, combined diesel powered heating and start/stop system, battery-diesel hybrid switching locomotive, and plug-in units appear to be more cost-effective, whereas the use of B20 biodiesel appears to be less cost effective. However, combined diesel powered heating and start/stop system, battery-diesel hybrid switching locomotive, and biodiesel practices have the potential to achieve large magnitudes of GHG emissions reductions, but plug-in units could only contribute small magnitude of GHG emissions reductions because this practice can be only used in switching yard; therefore, this restriction limits its potential for GHG emissions reductions and energy reduction.

58

Table 5- 2.

a

b c

Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Rail Modea


2-1

2-2

2-3

2-6

Name

Combined Diesel Powered Heating System and Auto Engine Start/stop System

Battery Diesel Hybrid Switching Locomotive

Plug-In Unit

B20 Biodiesel

Subgroup

Anti-idling

Anti-idling

Anti-idling

Responsible Parties

26, 27, 28, 35, 36, 37

26, 27

26, 27

Target Parties Target GHGs Strategy Types Developmental Status Modal GHG Emission Reduction (106 ton CO2 eq./year) Modal Energy Use Reduction (1012 BTU/year) Annualized Costs ($ 106/year) Annual Energy Cost Saving ($ 106/year) Net Saving ($ 106/year) Net Saving per Unit of GHG Emissions Reductions ($/ton CO2 eq.) Net Saving per Unit of Energy Use Reduction ($/ton CO2 eq.) Simple Pay-back Period (years)

11, 13 CO2 Technology P

11 CO2 Technology C

11 CO2 Technology P

Alternative Fuel 23, 25, 26, 28, 29 8, 10 CO2 Technology N

2.3

1.1

0.4

3.5

29

14

4

-42

140

180

91

380

530

260

230

0

390

70

135

-380

167

65

364

-109

13.5

5.2

38

N/Ab

2.1

5.5

0.8

N/Ac

These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. Cost results are presented only for those best practices for which adequate data were available. This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. There is no pay-back period for this best practice because there is no net saving.

59

6.0.

BEST PRACTICES FOR THE AIR MODE

This chapter identifies and characterizes 10 potential best practices applicable to the air mode. These best practices are divided into 5 subgroups, including: aerodynamic drag reduction; air traffic management; weight reduction; ground support equipment improvement; and engine improvement. Details regarding these best practices are in Appendix C. This chapter provides an overview of several potential best practices for greenhouse gas emissions reductions for the aviation freight transportation mode. However, this work is merely illustrative of possible best practices. Potential best practices were identified based on literature review. However, there may be other potential best practices that are not addressed here. Furthermore, in some cases, although potential best practices might be identified in the literature qualitatively, there is a lack of quantitative estimates of the possible impact of these potential best practices on emissions reductions. In general, there is a lack of reliable cost data for aviation potential best practices. Therefore, the information provided here is considered to be an initial but limited starting point for further identification and characterization of aviation freight potential best practices. For aviation freight, there are many means by which to achieve reductions in fuel use and greenhouse gas emissions. These include potential changes in operations, aircraft design, engine design, fuels, and ground support, among others. For example, operations includes air traffic control, standard procedures for operation and movement of the aircraft on the ground, take-off and landing procedures, and so on. For example, take-off procedures with derated or reduced thrust are estimated to reduce emissions of criteria air pollutants, such as NOx, but may slightly increase the fuel consumption and GHG emissions.80 In some cases, the potential best practices may be many years from realization, and thus there is limited information upon which to base an assessment at this time (e.g., IPCC, 1999).81 In addition to technical options for potential best practices, there are policy options for strategies that potentially could reduce energy use and greenhouse gas emissions. For example, policy options for reducing the growth of emissions from the air mode may include more stringent regulations, reductions of subsidies and incentives that currently lead to negative environmental impacts, market-based mechanisms (e.g., carbon tax and emissions trading), voluntary agreements, research programs, and inter-modal shifts. However, the efficacy and costs of such approaches are not adequately characterized for purposes of analysis here.81

60

6.1


Most of the fuel consumed by airplanes is needed to overcome aerodynamic drag, since they fly at very high speed. Reduction of aerodynamic drag can significantly improve the fuel efficiency of airplanes.82 Aerodynamic drag can be reduced by installing add-on devices, such as film surface grooves, hybrid laminar flow technology, blended winglets, and spiroid tips. 6.1.1 Best Practice 3-1: Surface Grooves Skin friction drag, also referred to as viscous drag, is caused by the contact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesive-backed film with micro-grooves that is placed on the exterior surfaces of the wings and the fuselage of the airplane. The series of microscopic grooves produces a drag-reducing surface. The reduction in skin friction drag results in a decrease in fuel use. Based upon results of wind tunnel and flight tests, this device is estimated to reduce total aerodynamic drag by up to 1.6%.82 The estimated potential reduction in modal GHG emissions is 1.6%. The disadvantage of this practice is that the lifetime of the film with micro-grooves is only 2 to 3 years. Thus, research is needed to improve the durability of the materials for the film. 6.1.2 Best Practice 3-2: Hybrid Laminar Flow Technology Aerodynamic drag associated with skin friction can be reduced if turbulent air flow can be replaced by laminar airflow over the aircraft skin surface. Laminar flow is a smooth air flow moving across an airfoil without turbulence, but it is usually destroyed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surface, such as the accumulation of ice, insects or other debris, degrades laminar flow. A newly developed concept, hybrid laminar flow technology, integrates both passive and active approaches to maintain laminar flow. A passive device requires no energy for its operation. An active device requires a source of energy for its operation. Passive anti-contamination devices are used to prevent or minimize contamination. Examples of such devices include: design of the wing surface geometry to have favorable pressure gradient; insect shields, removable coverings, continuous liquid dischargers and deflectors to prevent insect contamination; and anti-freeze agent dischargers and heat application techniques to avoid ice accumulation.83 An example of a passive anti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be used for ice and insect-contamination prevention.84 An active approach, a suction system, is comprised of a multi-layer panel on a wing 61

surface. The multi-layer panel includes a thin outer layer with fine pores and a thicker inner layer. The space between these two layers is divided into chambers. Air is sucked through the pores on the outer layer, then is vented through ducts out of the aircraft.84 The ducts are located to avoid negative impact to the aerodynamic performance of the aircraft. The air suction process can reduce air flow turbulence to maintain laminar flow on the surface of a wing.82,84-85 Taking into account the power used for suction, the combination of these passive and active approaches can reduce fuel use by 6% to 10%.82 The estimated potential reduction in modal GHG emissions is 6.0%. 6.1.3 Best Practice 3-3: Blended Winglet Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially available wing-tip device that can reduce lift-induced drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a smooth blended shape that can decrease the tip vortex intensity. From the results of field tests, the weakened vortex intensity caused by a blended winglet decreases lift-induced drag by 4% and reduces energy use by 2%.82 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the surface area increase is accounted for in the estimate given here. 6.1.4 Best Practice 3-4: Spiroid Tip An alternative type of wing-tip device is a spiroid tip. This device has been pilot tested and, like blended winglets, is intended to reduce lift-induced drag. A spiroid tip is a spiral loop formed by joining vertical and horizontal winglets. This technique can decrease tip vortex intensity and, therefore, reduce lift-induced drag. From the results of model simulations, spiroid tip can reduced lift-induced drag by 3.3% and reduce energy use by 1.7%.82 The estimated potential reduction in modal GHG emissions and energy use are both 1.7%. This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the surface area increase is accounted for in the estimate given here. 6.2

Air Traffic Management ― Best Practice 3-5

Optimized air traffic management systems are in the development stage. Compared to the current air traffic control system, there are opportunities to reduce congestion and improve 62

aircraft routing in order to reduce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient route options, and increase situation awareness. These systems are expected to reduce aviation fuel use by 6 to 12 percent, depending on the implementation of international arrangements.81 The estimated potential reduction in modal GHG emissions and energy use are both 6.0%. Air traffic management improvement is a potential best practice. An example of such an approach is the implementation of Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM). The concept of CNS/ATM, formerly known as the future air navigation systems (FANS) concept, was created by the International Civil Aviation Organization (ICAO), in cooperation with the aviation civil community. This concept aims at improving traffic control and airline management by applying new technologies, such as satellites and advanced computers, data links, and advanced flight avionics, to enhance capabilities of satellite-based navigation and digital data link communication systems. With the enhanced capabilities, the combination of new CNS technologies and the next generation of ATM systems will reduce fuel use, emissions, noise, and airspace congestion.86 In the US, the Federal inter-agency Joint Planning and Development Office (JPDO) has been established based on “Vision-100” legislation (Public Law 108-176) signed by the President in December 2003. JPDO is designing an advanced air transportation system, the Next Generation Air Transportation System (NextGen), which is intended for deployment by 2025.87 Many technologies are being developed for NextGen, such as the Automatic Dependent Surveillance Broadcast (ADS-B) and the System Wide Information Management (SWIM).88 ADS-B is a satellite-based surveillance and control systems intended to replace traditional ground-based surveillance and control systems. ADS-B includes aircraft on-board navigation systems and data-links. The former collects aircraft position and velocity data. The later automatically transmits data to air traffic control radar systems. The application of ADS-B will enhance operational efficiency and reduce fuel use by reducing visibility restrictions because pilots will be able to see what air traffic controllers see.86,88 SWIM is a networking-based initiative that will link needed information, such as position, weather, and restricted airspace notices, and will deliver high-quality, timely data to users involved in the NextGen system. SWIM will reduce the number and types of interfaces and systems, thereby enhancing operational efficiency and expanding system capacity.88 The implementation of CNS/ATM or the NextGen systems will provide new capabilities.88,89 Three examples of new capabilities are: (1) Reduced Vertical Separation Minimum (RVSM): The RVSM is a procedure that allows air traffic controllers and pilots to reduce the standard required vertical separation from 2,000 feet to 1,000 feet between aircraft 63

flying at altitudes between 29,000 and 41,000 feet. The RVSM will enhance aircraft operating efficiency by increasing the number of more fuel and time efficient flight altitudes.90,91 (2) Continuous Descent Approach (CDA): The conventional “dive-and-drive” aircraft arrival and approach procedures requires the use of high thrust, the deployment of flaps and landing gear to slow the aircraft while it levels off at different stages, which results in additional fuel consumption, noise and pollution. The CDA is a procedure that optimizes the aircraft landing. CDA involves a continuous descent of the aircraft on a constant slope without need to deploy flaps and landing gear. CDA flight tests in 2004 demonstrated reductions in fuel consumption of 900 lb to 1,500 lb compared to a conventional approach.88,92 (3) Oceanic Trajectory-Based Operations: Aircraft currently use designated routes to fly over oceanic airspace. Trajectory-based operations would enable pilots to tailor their individual flight paths based on four-dimensional trajectories, which include altitude, longitude, latitude, and time, of other aircraft. The advantages of trajectory-based operations are avoided congestion, more efficient use of airspace, and reduction in fuel use.88 6.3

Weight Reduction

Reductions in the weight of aircraft through the use of light-weight materials and weight reduction of non-essential components could lead to significant reductions in fuel use.81 6.3.1 Best Practice 3-6: Airframe Weight Reduction The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced lighter and stronger materials in the structural components of the airframe, such as aluminum alloy, titanium alloy, and composite materials for non-load-bearing structures, can reduce airframe weight, thereby leading to a reduction in fuel use.81 The International Civil Aviation Organization (ICAO) estimated that adoption of such materials can reduce structural weight by 4%.93 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. More research and development is needed to reach the projected structure weight reduction target. 6.3.2 Best Practice 3-7: Non-Essential Weight Reduction Trimming non-essential weight from aircraft can reduce fuel use. Adjustments to the amount of fuel, water, and emergency equipment onboard with respect to anticipated 64

requirements and a contingency allowance can reduce fuel use by no more than 1%.81 estimated potential reduction in modal GHG emissions is 1.0%. 6.4

The

Ground Support Equipment Improvement

Ground support equipment can be designed and deployed to help reduce energy use on-board aircraft, or can be redesigned to be more fuel efficient. Potential best practices for ground support equipment include supplying energy for aircraft operation on the ground and substation of electric and hybrid delivery trucks for conventional trucks.81,94-97 6.4.1

Best Practice 3-8: Ground-Based Equipment as an Alternative to Auxiliary Power Units Aircraft auxiliary power units (APUs) are engine-driven generators that supply electricity for use aboard the plane while at a cargo loading area. An alternative method for supplying electricity is to connect the aircraft to shore-based power or to use ground-based equipment to generate power for delivery to the aircraft. Such ground-based equipment has been pilot tested. Ground-based equipment can reduce APU fuel use significantly while the aircraft is at the gate.94 The reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-9. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%.96-97 6.4.2 Best Practice 3-9: Electric or Hybrid Heavy Duty Delivery Trucks Off-road electric or hybrid vehicles for supporting airport operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicle can operate for 100 miles after a single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles per hour, and climb grades up to 10%. These capabilities are suitable for ground equipment service. Other alternative ground support equipment propulsion systems can be based on LPG or gasoline powered hybrid vehicles.94-95 As explained in Section 6.4.1, the reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-8. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%.96-97 Reduction in cost is needed to expand the market penetration potential of this practice. 6.5

Engine Improvement ― Best Practice 3-10: Improved Engine Overall Efficiency

Current aircraft energy efficiency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile.98 Aircraft fuel consumption can be 65

reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure ratio of compressor and better mixing of fuel and air prior to combustion. A new jet engine with several advanced technologies is being developed and is scheduled to enter the market in 2008. One of the engine technologies features larger fan sizes to reach high engine bypass ratio by 9.5,99 which is higher than 5 to 9 bypass ratios of today’s most advanced engines.81 The increased fan weight caused by larger size is offset by a reduced number of fan blades and the use of composite materials. This engine is also equipped with a high-pressure compressor that produces a 23:1 pressure ratio. Engine efficiency can be improved further by better mixing of fuel and air, which leads to a more homogenous lean fuel/air mixture that burns more evenly, thereby reducing local pockets of incomplete combustion. Moreover, a fuel-efficient technology that runs the high-pressure turbine clockwise and the low-pressure turbine counterclockwise has been demonstrated in tests and is also included in the new engine design. Based on vendor information, this technology is estimated to reduce fuel use by 13.0%.99-100 The estimated potential reduction in modal GHG emissions and energy use are both 13.0%. 6.6

Summary of Potential Best Practices for the Air Mode

All 10 potential best practices, sorted by 5 subgroups, for the air mode are summarized in Table 6-1. They are in table format for the convenience of readers. 6.7


Figure 6-1 illustrates the variability among the potential best practices with respect to estimated reductions in modal GHG emissions. The percentage reductions in modal GHG emissions range from 1.0 to 13.0 percent when comparing individual best practices. However, these percentage reductions cannot be summed to obtain a total emission reduction. Some best practices are mutually exclusive or have interactions with others. For all of the 10 identified best practices for the air mode, there is a lack of sufficient information to support quantitative assessments. For these strategies, qualitative assessments are summarized in simplified summary tables individually. If sufficient information becomes available in the future, best practices that are assessed here qualitatively could be reassessed quantitatively.

66

Table 6- 1. List and Description of Potential Best Practices for the Air Mode Type of Description Subgroup Strategies 3-1. Surface Grooves Skin friction drag, also referred to as viscous drag, is caused by the contact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesive-backed film with micro-grooves, each a few thousandths of an inch wide, that is placed on the exterior surfaces of the wings and the Technology fuselage of the airplane. These grooves are called V-groove riblets. Riblets produce a drag-reducing surface. The reduction in skin friction drag results in a decrease in fuel use. Based upon results of wind tunnel and flight tests, this device is estimated to reduce total aerodynamic drag by up to 1.6%.82 The estimated potential reduction in modal GHG emissions and energy use are both 1.6%. One disadvantage of the riblet is that its lifetime is only 2 to 3 years.82 3-2. Hybrid Laminar Flow Technology Aerodynamic drag associated with skin friction can be reduced if turbulent air flow can be replaced by laminar airflow over the aircraft skin surface. Laminar flow is a smooth air flow moving across an airfoil without turbulence, but it is usually destroyed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surface, such as the accumulation of ice, insects or other debris, degrades laminar flow. A newly developed concept, hybrid laminar flow technology, integrates both passive and active Aerodynamic approaches to maintain laminar flow. A passive device requires no energy Drag for its operation. An active device requires a source of energy for its Reduction operation. Passive anti-contamination devices are used to prevent or minimize contamination. Examples of such devices include: design of the wing surface geometry to have favorable pressure gradient; insect shields, removable coverings, continuous liquid dischargers and deflectors to Technology prevent insect contamination; and anti-freeze agent dischargers and heat application techniques to avoid ice accumulation.83 An example of a passive anti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be used for ice and insect-contamination prevention.84 An active approach, a suction system, is comprised of a multi-layer panel on a wing surface. The multi-layer panel includes a thin outer layer with fine pores and a thicker inner layer. The space between these two layers is divided into chambers. Air is sucked through the pores on the outer layer, then is vented through ducts out of the aircraft.84 The ducts are located to avoid negative impact to the aerodynamic performance of the aircraft. The air suction process can reduce air flow turbulence to maintain laminar flow on the surface of a wing.82,84-85 Taking into account that the power used for suction is approximately 1% of aircraft fuel use, the combination of these passive and active approaches can reduce fuel use by 6% to 10%.82 The estimated potential reduction in modal GHG emissions is 6.0%.


Table 6-1. Continued Type of Subgroup Strategies

Description

3-3. Blended Winglet Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially available wing-tip device that can reduce lift-induced drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a Technology smooth blended shape that can decrease the tip vortex intensity. From the results of field tests, the weakened vortex intensity caused by a blended winglet decreases lift-induced drag by 4% and reduces energy use by 2%.82,101 This practice, however, increases surface area that increases the Aerodynamic viscous drag.82 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. Drag Reduction 3-4. Spiroid Tip An alternative type of wing-tip device is a spiroid tip. This device has been pilot tested and, like blended winglets, is intended to reduce lift-induced drag. A spiroid tip is a spiral loop formed by joining vertical and horizontal winglets. This technique can decrease tip vortex intensity Technology and, therefore, reduce lift-induced drag. From the results of model simulations, spiroid tip can reduced lift-induced drag by 3.3% and reduce energy use by 1.7% or more.82 This practice, however, increases surface area that increases the viscous drag.82 The estimated potential reduction in modal GHG emissions and energy use are both 1.7%. 3-5. Air Traffic Management Improvement Air traffic management systems are designed for the guidance, separation, coordination, and control of aircraft movements. Today’s air traffic control systems have limitations which result in traffic congestion and inefficient routings. For example, aircraft operators in existing system need to follow established, inefficient airways. These limitations result in the increase of fuel use, air pollutants emissions, and GHG emissions. Air Traffic Optimized air traffic management systems are in the development stage. Operation Management Compared to the current air traffic control system, there are opportunities to reduce congestion and improve aircraft routing in order to reduce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient route options, and increase situation awareness. These systems are expected to reduce aviation fuel use by 6 to 12 percent, depending on the implementation of international arrangements.84 The estimated potential reduction in modal GHG emissions and energy use are both 6.0%.


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Description

3-6. Airframe Weight Reduction The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced lighter and stronger materials in the structural components non-load-bearing structures of the airframe, such as aluminum alloy, titanium alloy, and composite materials for, can reduce airframe weight, thereby leading to a reduction in fuel use. Some design technologies, such as high-fidelity finite element models (FEMs), can be used for strength analysis to understand safety load-factor margins and reduce structural weight.81 Historical trends demonstrated that airplane manufactures keep decreasing structural weight of airframes. For Technology example, the Boeing 777, which is developed a decade ago, had an airframe with 10% composite structure by weight. The newly introduced Airbus 380 has an airframe with 25% composite structure by weight. The Boeing 787, scheduled for delivery beginning in 2008, will have an airframe with 50% composite structure by weight.102 The International Civil Aviation Organization (ICAO) estimated that adoption of such materials can reduce structural weight by 4%.93 Weight However, improved techniques for Reduction investigating the airframe with composite material are needed to avoid structure failure.102 The estimated potential reduction in modal GHG emissions and energy use are both 2.0%. 3-7. Non-Essential Weight Reduction Trimming non-essential weight from aircraft can reduce fuel use. Additional non-essential weight has several sources, such as extra aviation fuel, potable water and emergency equipments. Aviation fuel onboard is usually more than that required by the flight plan. Carrying extra fuel is because of several reasons, such as safety concern, fuel price difference among two places, fuel availability at some remote sites, fuel quality Operation concern at some locations, or insufficient time for refueling. Carrying extra potable water and emergency equipment also increase non-essential weight of aircrafts. Adjustments to the amount of fuel, water, and emergency equipment onboard with respect to anticipated requirements and a contingency allowance can reduce fuel use by no more than 1%.81 The estimated potential reduction in modal GHG emissions and energy use are both 1.0%. 3-8. Ground-Based Equipment as Alternative to Auxiliary Power Units Aircraft auxiliary power units are engine-driven generators that supply electricity for use aboard the plane while at a cargo loading area. An alternative is to connect the aircraft to shore-based power or to use Ground ground-based equipment to generate power for delivery to the aircraft. Support Technology Such equipment has been pilot tested. Ground-based equipment can Equipment reduce APU fuel use significantly while the aircraft is at the gate.81 The Improvement reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-9. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%.96-97



Description

3-9. Electric or Hybrid Heavy Duty Delivery Trucks Off-road electric or hybrid vehicles for supporting airport operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicle, equipped with a 320 volt AC drive train, can operate for 100 miles after a Ground single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles Support Technology per hour, and climb grades up to 10%. These capabilities are suitable for Equipment ground equipment service. Other alternative ground support equipment Improvement propulsion systems can be based on LPG or gasoline powered hybrid vehicles.94-95 As explained in Section 6.4.1, the reported estimates of fuel use and GHG emissions reductions for this best practice are combined with those of Best Practice 3-8. The estimated combined reduction in modal fuel use and GHG emissions for Best Practices 3-8 and 3-9 are 2.9%.96-97 3-10. Improved Engine Overall Efficiency Current aircraft energy efficiency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile.98 Aircraft fuel consumption can be reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure ratio of compressor and better mixing of fuel and air prior to combustion. A new jet engine with several advanced technologies is being developed and is scheduled to enter the market in 2008. One of the engine technologies features larger fan sizes to reach high engine bypass ratio by 9.5,99 which is higher than 5 to 9 bypass ratios of today’s most advanced Engine Technology engines.81 The increased fan weight caused by larger size is offset by a Improvement reduced number of fan blades and the use of composite materials. This engine is also equipped with a high-pressure compressor that produces a 23:1 pressure ratio. Engine efficiency can be improved further by better mixing of fuel and air, which leads to a more homogenous lean fuel/air mixture that burns more evenly, thereby reducing local pockets of incomplete combustion. Moreover, a fuel-efficient technology that runs the high-pressure turbine clockwise and the low-pressure turbine counterclockwise has been demonstrated in tests and is also included in the new engine design. Based on vendor information, this technology is estimated to reduce fuel use by 13.0%.99-100 The estimated potential reduction in modal GHG emissions and energy use are both 13.0%.

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14 12 10 8 6 4 2 0 3-1

3-2

3-3

3-4

3-5

3-6

3-7

3-8 *

3-9 * 3-10

Best Practice Number for the Air Mode *The reduction in modal GHG emissions for Best Practice 3-9 represents the estimated combined reduction in modal GHG emissions for Best Practices 3-8 and 3-9

Figure 6- 1. Reductions in Modal GHG Emissions for the Best Practices for the Air Mode

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7.0

BEST PRACTICES FOR THE WATER MODE

This chapter identifies and characterizes five potential best practices applicable to the water mode. These best practices are divided into three subgroups, including: • improved propeller system; • anti-idling; and • alternative fuel. Additional details regarding all of these best practices are in Appendix D. For one of these best practices, sufficient data were available to quantify costs. 7.1

Propeller System Improvement

A ship uses a propeller to convert ship engine power into thrust for propulsion of the ship. As ships move through the water, they produce energy-consuming turbulent vortices depending on speed, ship hull geometry, and propeller design. A number of modified propeller systems have been introduced in order to improve the overall energy efficiency of ship propulsion. These systems are designed based on attempts to recover energy from turbulent vortices in the water, or to prevent the formation of such vortices. This, in turn, leads to reduction in ship fuel use and exhaust CO2 emissions.103-105 7.1.1 Best Practice 4-1: Off-Center Propeller The movement of the ship through water produces vortices in the water. The formation of such vortices requires energy. Thus, a portion of the energy expended to move the ship is transferred to the creation of such vortices. For example, vortices that are formed along the rear part of the ship and that flow into the wake are the result of turbulence. Such vortices are referred to as “bilge vortices” and they effectively increase the resistance of water movement around the ship hull. An off-center propeller is a commercially available device that attempts to capture some of the flow and energy contained within the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder and properly shaft located away from the longitudinal centerline of the ship. From the result of tank tests, an off-center propeller was estimated to reduce ship propulsion energy use by 3% or more. This practice can be implemented for new ships but is difficult or impractical to retrofit to existing ships. This practice was combined with a refined hull shape and other energy-saving measures in a large ore carrier, which lead to a total estimated reduction in energy use of 14%.103 The estimated potential reduction in modal GHG emissions is 1.5%, assuming that the off-center 72

propeller alone contributed only partially to the total estimated reduction in energy use of the ore carrier, as well as implementation on only a portion of freight ships. This practice can be implemented for new ships but it is difficult or impractical to retrofit to existing ships. 7.1.2 Best Practice 4-2: Propeller Boss Cap with Fins (PBCF) Turbulent vortices are generated by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy efficiency of the propulsion system. A method for reducing the formation of vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF).104 PBCF is commercially available, and approximately 1,000 ships have adopted this practice as of 2006.106 The PBCF includes small fins installed behind the propeller and that rotates in the same direction as the propeller. The purpose of these fins is to avoid the formation of vortices. From the results of field tests, this device appears to be able to reduce propulsion fuel use by 4 to 5 percent.104 The estimated potential reduction in modal GHG emissions is 2.0%, assuming either less effectiveness in practice or implementation on only a portion of freight ships. 7.1.3

Best Practice 4-3: Auxiliary Free-Rotating Propulsion Device behind the Main Propeller As noted in the previous section, propeller rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. An alternative to PBCF is a grim vane wheel (GVW). GVW is a commercially available device, and approximately 59 ships had adopted this practice as of 2000.107 It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is located immediately behind the main propeller. The rotation of GVW modifies the accelerated flow of water that is leaving the propeller, recovers a portion of the energy embodied in the accelerated flow of water, and in so doing provides extra propulsion. A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability. From the results of field tests, GVW techniques may reduce propulsion fuel use by 6% or more.105107 Taking into account that not all ships will adopt this technique, the estimated potential reduction in modal GHG emissions is 3.0%. 7.2

Anti-Idling ― Best Practice 4-4: Shoreside Power for Marine Vessels at Ports

Shoreside power is being tested as ship anti-idling system that can avoid the need for running the ship auxiliary engine continuously while a ship is docked at a port. Shoreside 73

power is a system that connects the ship to an external electrical power source, thereby avoiding the need for use of the auxiliary engine. Thus, this system can reduce ship fuel use and GHG emissions. Taking into account reduced shipboard energy use and emissions, and increased shoreside energy use and emissions to produce electricity, shoreside power can reduce overall GHG emissions compared to an auxiliary engine by 13%.108-109 However, the fuel use for the auxiliary engine is only a small fraction of total marine fuel use. Assuming that only a fraction of all ships adopts this technique and that ship auxiliary engines only use a small fraction of marine fuel, the estimated potential reduction in modal GHG emissions is 0.2%. 7.3

Alternative Fuel ―Best Practice 4-5:

B20 Biodiesel Fuel for Ships

Large ocean-going ships usually have multiple engines, including main engines and auxiliary engines. Since 1980, all marine engines have been diesel-powered engines. Main marine engines usually burn residual fuel or blends of residual and distillate fuels.110 Auxiliary engines usually burn marine gas oil, a high sulfur diesel fuel that is usually the fuel for small and medium sized marine engines. Thus, ocean-going ships often carry both residual fuel oil and marine gas oil.111 For marine fuel consumption, residual fuel oil for freight ships is about 60% of total marine fuel use. Distillate fuel for freight ships is about 11% of total marine fuel use. Distillate fuel for other ships (such as passenger ships, fish ships, military ships) accounts for other 29% of marine fuel use.112 B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for marine gas oil powered diesel engines.113 Based on a life cycle analysis, the CO2 emissions are estimated to decrease by 0.0069 tons CO2 eq. per 106 BTU for B20 biodiesel compared to land-use diesel fuel. Land-use diesel fuel and marine gas oil are both distillate fuels but differ in that land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO2.111 Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. The difference of life cycle GHG emission analysis results between B20 biodiesel and marine gas oil should be lower than the difference between B20 biodiesel and land-use diesel fuel. Thus, the latter provides a useful upper bound of the former. Taking into account that only a fraction of marine fuel is marine gas oil, the estimated potential reductions in modal GHG emissions are 1.2%.13,63-64,112,114-115 The estimated potential modal energy use increases by 1.3%.61

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7.4

Summary of Potential Best Practices for the Water Mode

All five potential best practices, sorted by three subgroups, for the water mode are summarized in Table 7-1. They are in table format for the convenience of readers. 7.6


Figure 7-1 illustrates the variability among the potential best practices with respect to estimated reductions in modal GHG emissions. These percentage reductions in modal GHG emissions range from 0.2 to 3.0 percent when comparing individual best practices. However, these percentage reductions cannot be summed to obtain a total GHG emission reduction. Some best practices are mutually exclusive with others, as described later in Chapter 9. 7.7

Quantitative Cost Results for the Water Mode

Quantitative cost results for the best practices for which sufficient information was available to perform such assessments are summarized in standardized reporting tables, which are given in Appendix D. In contrast, assessment results for the best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix D. To date, there is sufficient information for one best practice upon which to make quantitative assessments. The other four best practices are assessed qualitatively. The best practice assessed quantitatively is B20 biodiesel for ships. Table 7-2 summarizes the quantitative assessment results of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for this selected best practice. For B20 biodiesel, the net savings are negative. B20 biodiesel fuel cost is higher than that for marine gas oil, and thus there is a net increase in total costs. The use of B20 has the potential to achieve a larger magnitude of total GHG emissions reductions.

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Table 7- 1. List and Description of Potential Best Practices for the Water Mode Subgroup

Type of Strategies

Description

4-1. Off-Center Propeller The movement of the ship through water produces vortices in the water. The formation of such vortices requires energy. Thus, a portion of the energy expended to move the ship is transferred to the creation of such vortices. For example, vortices that are formed along the rear part of the ship and that flow into the wake are the result of turbulence. Such vortices are referred to as “bilge vortices” and they effectively increase the resistance of water movement around the ship hull. An off-center propeller is a commercially available device that attempts to capture some of the flow and energy contained within the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder and properly shaft located away from Propeller System Technology the longitudinal centerline of the ship. For a ship with clockwise rotating propeller, the propeller is moved to starboard of the ship. For Improvement a ship with anti-clockwise rotating propeller, the propeller is moved to port of the ship. From the result of tank tests, an off-center propeller was estimated to reduce ship propulsion energy use by 3% or more. This practice can be implemented for new ships but is difficult or impractical to retrofit to existing ships. This practice was combined with a refined hull shape and other energy-saving measures in a large ore carrier, which lead to a total estimated reduction in energy use of 14%.103 The estimated potential reduction in modal GHG emissions is 1.5%, assuming that the off-center propeller alone contributed only partially to the total estimated reduction in energy use of the ore carrier, as well as implementation on only a portion of freight ships.


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Type of Strategies

Description

4-2. Propeller Boss Cap with Fins Turbulent vortices are generated by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy efficiency of the propulsion system. A ship propeller generates hub vortices behind it during operation. Water very close to the hub (e.g., 3 mm) flows along the direction of propeller rotation, but water that has a small distance from the hub (e.g., 10 mm) flows in the opposite direction. These conflicting flows produce hub vortices that consume more energy. A method for reducing the formation of hub vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF).104 Propeller PBCF is commercially available, and System Technology approximately 1,000 ships have adopted this practice as of 2006.106 Improvement The PBCF includes small fins that the number of fins is as the same as that of propeller blades. It is installed behind the propeller and that rotates in the same direction as the propeller. The purpose of these fins is to block water in hub vortices, move water along the direction of propeller rotation, and produce a straight slip stream behind the propeller. From the results of field tests, this device appears to be able to reduce propulsion fuel use by 4 to 5 percent.104 The estimated potential reduction in modal GHG emissions is 2.0%, assuming either less effectiveness in practice or implementation on only a portion of freight ships. The estimated capital cost of PBCF ranges from $20,000 for 735 kW engine to $146,000 for 22,050 kW engine, which can be recovered within two years by fuel cost savings.


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Type of Strategies

Description

4-3. Auxiliary Free-Rotating Propulsion Device behind the Main Propeller As noted in the previous section, propeller rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. Ship propeller produces accelerated flow in the propeller wake that consumes energy. An alternative to PBCF is a grim vane wheel (GVW). GVW is a commercially available device that transfers accelerated flow in the wake into extra propulsion and increases fuel efficiency. Approximately 59 ships had adopted this practice as of 2000.107 It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is Propeller located immediately behind the main propeller. The rotation of GVW Technology System modifies the accelerated flow of water that is leaving the propeller, Improvement recovers a portion of the energy embodied in the accelerated flow of water, and in so doing provides extra propulsion. Older designs of GVW are mounted on the propeller shaft, but can have problems with mechanical failure. A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability.105 From the results of field tests, GVW techniques may reduce propulsion fuel use by 6% or more.107 Taking into account that not all ships will adopt this technique, the estimated potential reduction in modal GHG emissions is 3.0%. The estimated capital cost of new-designed GVW is approximately $1.2 million dollars, which can be recovered in about three years based on fuel cost savings. 4-4. Shoreside Power for Marine Vessels at Ports Shoreside power is being tested as ship anti-idling system that can avoid the need for running the ship auxiliary engine while a ship is docked at a port. A docked ship usually runs its on-board auxiliary engine continuously, which consumes energy and emits criteria air pollutants and GHGs at the port. Shoreside power at the port allows for shut down of the auxiliary engine and reduces fuel use and emissions. From the result of a report for European Commission, CO2 emitted from the ship auxiliary engine ranges from 690 to 720 g/kWh,109 Average CO2 emissions from electricity production in the Anti-Idling Technology US are approximately 615 g/kWh.108 Taking into account reduced shipboard energy use and emissions, and increased shoreside energy use and emissions to produce electricity, this system reduces overall GHG emissions compared to auxiliary engine by approximately 13%. European Commission report estimates that 60% of marine vessels are suitable for use of shore-side electricity.109 Taking into account that only a fraction of all ships adopts this technique and the ship auxiliary engines only use a small fraction of marine fuel, the estimated potential reduction in modal GHG emissions is 0.2%. The installation of shoreside power for marine vessels at ports is likely to be phased-in over 5 to 10 years.116



Alternative Fuel

Type of Strategies

Description

4-5. B20 Biodiesel Fuel for Ships Large ocean-going ships usually have multiple engines, including main engines and auxiliary engines. Since 1980, all marine engines have been diesel-powered engines. Main marine engines usually burn residual fuel or blends of residual and distillate fuels.110 Auxiliary engines usually burn marine gas oil, a high sulfur diesel fuel that is usually the fuel for small and medium sized marine engines. Thus, ocean-going ships often carry both residual fuel oil and marine gas oil.111 For marine fuel consumption, residual fuel oil for freight ships is about 60% of total marine fuel use. Marine gas oil for freight ships is about 11% of total marine fuel use. Marine gas oil for other ships (such as passenger ships, fish ships, military ships) accounts for other 29% of marine fuel use. Thus, marine gas oil accounts for 15% of marine fuel for freight ships.112 B20 biodiesel, which is described in Section 4.11.2, is a potential alternative fuel for marine gas oil powered diesel engines.113 Based on Technology a life cycle analysis, the CO2 emissions are estimated to decrease by 0.0069 tons CO2 eq. per 106 BTU for B20 biodiesel compared to land-use diesel fuel. Land-use diesel fuel and marine gas oil belong to distillate fuel except that the land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO2.111 Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. The difference of life cycle GHG emission analysis results between B20 biodiesel and marine gas oil should be lower than the difference between B20 biodiesel and land-use diesel fuel. Thus, the latter provides a useful upper bound of the former. Taking into account that only a fraction of marine fuel is marine gas oil, the estimated potential reductions in modal GHG emissions are 1.2%.13,63-64,114-115 The estimated potential modal energy use increases by 1.3%.61

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3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 4-1

4-2

4-3

4-4

4-5

Best Practice Number for the Water Mode Figure 7- 1.

Reductions in Modal GHG Emissions for the Best Practices for the Water Mode

80

Table 7- 2.

a

b

c

Summary Table for the Comparison of the Quantitative Cost Results for A Selected Best Practices for the Water Modea Best Practice Number

4-5

Name Subgroup Responsible Parties Target Parties Target GHGs Strategy Types Developmental Status Modal GHG Emissions Reductions (106 ton CO2 eq./year) Modal Energy Use Reduction (1012 BTU/year) Annualized Costs ($ 106/year) Annual Energy Cost Saving ($ 106/year) Net Saving ($ 106/year) Net Saving per Unit of GHG Emissions Reductions ($/ton CO2 eq.) Net Saving per Unit of Energy Use Reduction ($/ton CO2 eq.) Simple Pay-back Period (years)

B20 Biodiesel Alternative Fuel 58, 61, 23, 25 CO2 Technology N 1.5 -18 180 0 -180 -120 N/Ab N/Ac

These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. Cost results are presented only for this best practice for which adequate data were available. This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving.

There is no pay-back period for this best practice because there is no net saving.

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8.0

BEST PRACTICES FOR THE PIPELINE MODE

This chapter identifies and characterizes 5 potential best practices applicable to the pipeline mode. The pipeline mode best practices focus on techniques or strategies applicable to natural gas pipelines. The main source of GHG emissions from these pipelines is leakage of natural gas, which is comprised mostly of methane. These best practices are divided into 3 subgroups, including: • Improved process control devices; • connecting method; and • maintenance. Additional details regarding all of these best practices are in Appendix E. these best practices, sufficient data were available to quantify costs. 8.1

For three of

Process Control Device Improvement

Natural gas pneumatic controls are used for pipeline operations. These controls are a source of methane leakage. Conversion of these controls to compressed instrument air systems or replacement of high-bleed with low-bleed devices, can reduce methane emissions significantly.117-119 8.1.1

Best Practice 5-1: Convert Natural Gas Pneumatic Controls to Instrument Air Pneumatic control systems for pipelines are currently operated using pressurized natural gas. However, pneumatic controls based on compressed air could be used instead. Since natural gas is continuously bled from the current control devices, they are one of the largest methane emissions sources in the natural gas industry.1,117 Conversion of pneumatic control systems from natural gas to compressed air would reduce methane emissions.117 Taking into account the electricity energy needed for powering the compressed instrument air powered systems, the estimated potential reductions in modal GHG emissions and energy use are 0.5% and 0.1%, respectively. Since this practice needs electricity for its operation, it can be applied only in locations near electricity grids or by installing engine-generator sets at remote sites. The estimates given here are based on use of electricity from the grid, not from an engine-generator set.

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8.1.2

Best Practice 5-2: Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Current high-bleed pneumatic control systems, which are approximately 26% of current installed pneumatic control systems for pipelines, are based on high-bleed compressed methane. An alternative designed is based on low-bleed. Replacing high-bleed with low-bleed devices is estimated to reduce methane emissions from the control system by 90%.118-119 Taking into account that methane vented from high-bleed pneumatic control systems is a small fraction of total methane emissions from the pipeline mode, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.2%, respectively. 8.2

Connecting Method ―Best Practice 5-3:

“Hot Tap” Pipeline Connecting Method

Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. This method avoids the need for venting natural gas. It involves attaching a branch pipeline connection on the outside of an operating pipeline and cutting out the inside pipeline wall. This practice would reduce natural gas emission.120-122 The estimated potential reductions in modal GHG emissions and energy use are 1.9% and 0.5%, respectively. 8.3

Maintenance

In the natural gas industry, fugitive emissions of methane are due to leaking pipelines, meters and regulating equipment. The improvement of inspection and maintenance processes can be a cost-effective way to reduce methane emissions. 8.3.1 Best Practice 5-4: Transfer Compression During the pipeline maintenance process, a section of pipe is often isolated and taken out for maintenance, and methane is vented from the isolated section. An alternative to venting is to transfer the natural gas in the isolated section to an operating section of the pipeline, thereby avoiding loss of methane. A system for doing this is a transfer compressor unit, which is commercially available. Several transfer compressors can be operated simultaneously to increase the methane recovery rate.121-123 The estimated potential reductions in modal GHG emissions and energy use are 0.1% and 0.02%, respectively. 8.3.2 Best Practice 5-5: Inline Inspection Pipeline flaws, especially stress corrosion cracking (SCC), cause pipeline failure that are 83

of safety concern and that lead to fugitive methane emissions. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” was originally designed to inspect internal pipeline conditions, such as dents or metal loss, by using ultrasound.124 A ultrasound inline inspection tool based on a newer design can detect not only dents or metal loss, but also SCC. This new tool is able to locate more pipeline flaws. By identifying and correcting such flaws sooner, fugitive methane emissions can be reduced.121 The estimated potential reductions in modal GHG emissions and energy use are 1.3% and 0.4%, respectively. 8.4

Summary of Potential Best Practices for the Pipeline Mode

All five potential best practices for the pipeline mode, organized by three subgroups, are summarized in Table 8-1. They are in table format for the convenience of readers. 8.5


Figure 8-1 summarizes the variability among the potential best practices with respect to estimated reductions in modal GHG emissions. These percentage reductions in modal GHG emissions range from 0.1 to 1.9 percent when comparing individual best practices. 8.6

Quantitative Cost Results for the Pipeline Mode

Quantitative cost results for the best practices for which sufficient information was available to perform such assessments are summarized in standardized reporting tables, which are given in Appendix E. In contrast, qualitative assessment results for the best practices which have a lack of sufficient information from which to quantify costs are summarized in simplified summary tables individually, which are also given in Appendix E. To date, there is sufficient information for three best practices upon which to make quantitative assessments. The other two best practices are assessed qualitatively. The best practices assessed quantitatively include: convert natural gas pneumatic controls to instrument air; replace high bleed natural gas pneumatic devices with low bleed pneumatic devices; and “hot tap” pipeline connecting method. Table 8-2 summarizes the quantitative assessment results of modal GHG emissions reductions, modal energy use reductions, annualized cost, energy cost saving, net savings, net savings per unit of GHG emissions reductions, net savings per unit of energy use reduction, and simple pay-back periods for these three selected best practices.

84


List and Description of Potential Best Practices for the Pipeline Mode Type of Strategies

Description

5-1. Convert Natural Gas Pneumatic Controls to Instrument Air Compressed air powered pneumatic control systems, which are the alternative to currently used natural gas powered systems, are commercially available devices that reduce GHG emissions. There are approximately 90,000 to 130,000 pneumatic control devices used in natural gas pipelines. They are used to actuate isolation valves, control liquid level, and regulate gas flow and pressure at compressor stations, pipelines, and storage facilities. These systems are usually powered by readily available high-pressure natural gas, and natural gas is constantly bled from these Technology devices. Thus, these devices contribute to GHG emissions.117 EPA estimates that approximately 8.46×109 tons methane were emitted in 2003 for pipeline operation.1 Conversion of natural gas-powered pneumatic control systems to compressed instrument air powered systems can reduce Process methane emissions.117 Taking into account the electricity energy needed Control for powering the compressed instrument air powered systems, the estimated Device Improvement potential reductions in modal GHG emissions and energy use are 0.5% and 0.1%, respectively. However, to implement instrument air systems, utility or self-generated electrical power should be available on site. 5-2. Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Low-bleed natural gas powered pneumatic control systems are commercially available. Of the existing natural gas powered control devices, 26% of them are high-bleed devices. Most high-bleed devices can be replaced or Technology retrofitted with low-bleed devices, thereby reducing the per-device methane emissions by 90%.118-119 Taking into account that methane vented from high-bleed pneumatic control systems is a fraction of total methane emission from the pipeline mode, the estimated potential reductions in modal GHG emissions and energy use are 0.6% and 0.2%, respectively. 5-3. “Hot Tap” Pipeline Connecting Method Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. Traditional connecting methods usually vent a significant amount of natural gas into atmosphere during their operation. This method avoids the need for venting natural Connecting Technology gas. It involves attaching a branch pipeline connection on the outside of an Method operating pipeline and cutting out the inside pipeline wall. This practice would reduce natural gas emission.120-122 The estimated potential reductions in modal GHG emissions and energy use are 1.9% and 0.5%, respectively. Natural gas cost saving is generally sufficient to justify the costs for hot tap method instead of the costs for traditional connecting methods. The simple pay-back period for this practice is approximately 12 months.


85


Type of Strategies

Description

5-4. Transfer Compression During the pipeline maintenance process, a section of pipe is often isolated and taken out for maintenance, and a significant amount of methane is vented into the atmosphere. A transfer compressor is a commercial available system that reduces methane emissions in this process. It pumps Technology natural gas from the isolated pipeline section to an operational section of the pipeline section, thereby decreasing the amount of vented methane. Several transfer compressors, which can be mounted on trucks, are operated at the same time.121,123 The estimated potential reductions in modal GHG emissions and energy use are 0.1% and 0.02%, respectively. 5-5. Inline Inspection Pipeline flaws, especially stress corrosion cracking (SCC), cause pipeline Maintenance failures that are of safety concern and that increase fugitive methane emissions. In order to ensure the integrity of the pipeline systems, these flaws must be detected and repaired. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” is a commercially available device that helps in detection of pipeline flaws.124 By correcting such flaws, fugitive methane Technology emissions are avoided. A newer design for an ultrasound inline inspection tool has been developed. This new-designed tool can detect not only dents or metal loss, but also SCC. The new tool is more sensitive in detecting problems, thereby enabling identification of problems sooner. This upgraded tool can find more flaws in the pipeline system and, therefore, enable quickly corrective action lead to larger reductions in fugitive methane emissions.121 The estimated potential reductions in modal GHG emissions and energy use are 1.3% and 0.4%, respectively.

86


2.5

2

1.5

1

0.5

0 5-1

5-2

5-3

5-4

5-5

Best Practice Number for the Pipeline Mode Figure 8- 1.

Reductions in Modal GHG Emissions for Best Practices for the Pipeline Mode

All three best practices produce net cost savings. These savings are the net result of substantial costs offset by substantial savings based on reduced energy usage. Although the hot tap method has the potential to achieve larger magnitudes of GHG emissions reductions and higher amount of net savings than those of the other two practices, all three practices appear to have a similar magnitude of cost-effectiveness when normalized by GHG emissions reductions.

87

Table 8- 2.

Summary Table for the Comparison of the Quantitative Cost Results for Selected Best Practices for the Pipeline Mode.a


Name

Subgroup

a

Responsible Parties Target Parties Target GHGs Strategy Types Developmental Status Modal GHG Emission Reduction (106 ton CO2 eq./year) Modal Energy Use Reduction (1012 BTU/year) Annualized Costs ($ 106/year) Annual Energy Cost Saving ($ 106/year) Net Saving ($ 106/year) Net Saving per Unit of GHG Emissions Reductions ($/ton CO2 eq.) Net Saving per Unit of Energy Use Reduction ($/ton CO2 eq.) Simple Pay-back Period (years)

5-1

5-2

Convert Natural Gas Pneumatic Controls to Instrument Air

70, 71, 72, 73 26, 27, 28 CH4 Technology C

Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Process Control Device Improvement 70, 71, 72, 73 26, 27, 28 CH4 Technology C

0.7

0.8

2.5

1

2

5

1.7

1.8

11

13

15

51

12

13

40

18

18

16

9.6

8.8

7.8

0.3

0.9

0.2


5-3

“Hot Tap” Method

Connecting Method 70, 71, 72, 73 26, 27, 28, 29 CH4 Technology C

These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. Cost results are presented only for those best practices for which adequate data were available.

88

9.0

SUMMARY AND COMPARISON OF GHG EMISSIONS REDUCTIONS FOR ALL FREIGHT TRANSPORTATION MODES

A total of 59 strategies have been identified as best practices in freight transportation. There are 33, 6, 10, 5, and 5 best practices for the truck, rail, air, water, and pipeline modes, respectively. Approximately half of the total number of best practices are for the truck mode. The purpose of this Chapter is to: z summarize the potential for reductions in GHG emissions, Energy use or Refrigerant Use (GERU) for individual best practices and subgroups; z summarize and evaluate the variability in GERU reductions and cost-effectiveness of the best practices among different modes, based on quantitative assessment results; and z

9.1

evaluate the potential impact of intermodal substitutions.

Truck Mode

Total GHG emissions reductions for all five modes are mainly attributable to reductions in energy use. However, a small portion of emissions reductions for the truck mode are contributed by reductions in refrigerant use or leakage. Table 9-1 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practices for the truck mode. These reductions are summarized in four ways: (1) The potential per-device reductions in GHG emissions and energy use for an individual best practice, which are the percentage reductions compared to emissions and energy use of a device that does not use the practice. (2) The potential reductions in modal GHG emissions and energy use for an individual best practice, which are the percentage reductions for a practice when it is used on all applicable devices for a mode. These reductions are compared to modal total emissions and energy use without use of this practice. (3) Percentage contributions of a subgroup to total reductions in modal GHG emissions and energy use if all best practices are implemented. (4) The magnitude of aggregate reductions in modal GHG emissions and energy use in 2025 if all best practices are used for each subgroup. The reductions in refrigerant use for best practices within the air conditioning improvement subgroup (I.D. No. 1-6 to 1-10) are not included in Table 9-1. Four of the five best practices in this subgroup have the potential to reduce GHG emissions by reducing 89

refrigerant leakage rate or use of low global-warming-potential refrigerants. Their potential modal GHG emissions reductions range from 0.9% to 2.5%. A small portion of the potential total GHG emissions reduction by 2025 for all 33 best practices for the truck mode is attributed to reduced refrigerant leakage rate or use of low GWP refrigerants. Some subgroups include best practices with complex conditions, such as mutual exclusion, interaction, and technological barriers. Some interactions exist not only among best practices within a subgroup, but also among best practices from different subgroups. (1) Anti-Idling (I.D. Nos. 1-1 to 1-5 in Table 9-1) Auxiliary power units are the basis for the estimated GHG emissions reductions for the anti-idling subgroup. Five best practices are mutually exclusive. The top two practices are auxiliary power units and direct-fired heaters with thermal storage units. The former is chosen here because operation of the later requires battery power and inhibits its acceptance by the market. (2) Air Conditioning System Improvement (I.D. Nos. 1-6 to 1-10 in Table 9-1) The assessment results of the estimated GHG emissions reductions for this subgroup are based on the choice of CO2 as a refrigerant. Three alternative refrigerants that could be used as best practices are mutually exclusive, since only one refrigerant can be used in an air conditioning system. CO2 is chosen here because it has the lowest GWP compared to the other candidate refrigerants and its potential reductions in modal GHG emissions are the highest. There is interaction between enhanced air conditioning systems with respect to direct emissions and low-GWP refrigerants. At a given leakage rate, the systems using low-GWP refrigerant contribute less GHG emissions than those using CFC-152a. Thus, the potential GHG emissions for enhanced air conditioning systems for direct emission are reduced if CFC-152a refrigerant is replaced by any of the low-GWP refrigerants. There is also interaction between enhanced air conditioning systems for indirect emissions and low-GWP refrigerants. More energy may be needed to operate some low-GWP refrigerant systems. For example, a propane based refrigerant system uses about 10% more energy for the operation of vehicle air conditioners and increases indirect GHG emissions The potential GHG emissions reduction for enhanced air conditioning systems for indirect emission may increase if alternative refrigerants are used. (3) Aerodynamic Drag Reduction (I.D. Nos. 1-11 to 1-16 in Table 9-1) This subgroup includes two best practices, pneumatic aerodynamic drag reduction (I.D. No. 1-14) and planar boat tail plates on tractor-trailers (I.D. No. 1-15), which are 90

mutually exclusive. They are mutually exclusive because both of these best practices are installed on the tails of tractor-trailer for aft-end drag reduction. They cannot both be implemented on the same truck. The former is chosen here because reductions by the former are estimated to be higher than the reductions by the latter. There is interaction between pneumatic aerodynamic drag reduction systems and some truck configurations. For example, the dimensions of the tractor-trailer gap may inhibit the reduction of aerodynamic drag achievable via this system. Thus, adopting another best practice that reduces the tractor-trailer gap may enhance the reduction potential of this practice. The available data for the effectiveness of aerodynamic drag reductions are based on individual field tests that do not take into account these interactions, and thus there is not an empirical basis for quantitatively estimating the effect of such interactions on reductions in vehicle fuel consumption.43 (4) Tire Rolling Resistance Improvement (I.D. Nos. 1-17 to 1-20 in Table 9-1) This subgroup includes two best practices, low rolling-resistance tires (I.D. No. 1-19) and wide-base tires (I.D. No. 1-20), which are mutually exclusive. They are mutually exclusive, since they cannot both be implemented on the same truck. Both of them can reduce GHG emissions by the same magnitude, so the results of the assessment are not sensitive to the choice between these two approaches. The estimates for low rolling-resistance tires are used here. (5) Transmission Improvement (I.D. Nos. 1-23 to 1-24 in Table 9-1) There is interaction between advanced transmissions (I.D. No. 1-23) and transmission friction reduction through low-viscosity transmission lubricants (I.D. No. 1-24). Advanced transmissions are designed to reduce internal friction, such as by reduction of gear surface roughness and by the use of low-friction coatings. Lubricants are also used to reduce gear contact friction. Thus, the total reduction may not be a simple linear combination of the reductions of these two practices. However, there is a lack of data with which to quantify the impact of the interaction. Thus, a simple linear combination of the reductions is applied. (6) Diesel Engine Improvement (I.D. Nos. 1-25 to 1-29 in Table 9-1) For the diesel engine improvement subgroup, there is an interaction between two practices: improved fuel injectors (I.D. No. 1-27); and turbocharged, direct injection to improved thermal management (I.D. No. 1-28). The former improves the fuel injection systems for all trucks. The latter improves the fuel injection systems for medium-duty trucks. Most heavy-duty trucks already have turbocharged systems. Since the former focuses on the improvement of fuel injection system and the latter also involves a change in the fuel injection system, the combined reduction may not be a 91

simple linear combination of the reductions of these two practices if implemented on the same. However, there is a lack of data with which to quantify the impact of the interaction. Thus, a simple linear combination of the reductions is applied for the former practice for heavy duty trucks and the latter practice for medium duty trucks. (7) Accessory Load Reduction (I.D. Nos. 1-30 to 1-31 in Table 9-1) Accessory load reduction can be achieved by conversion of mechanical auxiliary loads to electrically-operated ones. Furthermore, the electric power for auxiliaries can be obtained from an source separate from the truck base engine, such as a small fuel cell system or a small diesel engine with an alternator. Thus, these two best practices have common technology with respect to auxiliary loads, but differ in terms of the electric power supply system for the auxiliaries. Therefore, although the same kinds of electrically-operated auxiliary components can be used for both best practices, they differ in a mutually exclusive way because they are a based on different energy conversion systems. For purpose of making an upper bound estimate of the potential for auxiliary load reduction, the fuel cell-based energy conversion system with electrically operated auxiliaries is chosen, since this practice has the potential to reduce GHG emissions more than the small diesel engine-based system. The two most important subgroups for GHG emissions reduction are diesel engine improvement (I.D. Nos. 1-25 to 1-29) and aerodynamic drag reduction (I.D. Nos. 1-11 to 1-16). These two subgroups contribute 29 and 16 percent, respectively, to the estimated total modal GHG emissions reductions. 9.2

Rail Mode

Table 9-2 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practice for the rail mode. These reductions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, anti-idling (I.D. Nos. 2-1 to 2-3), includes best practices that are mutually exclusive. Rail companies usually use different types of locomotives for long-haul versus yard switching service. The latter locomotives typically have larger engines (e.g., 5,000 hp) than the former (e.g., 2,000 hp). Assuming that the national ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), the largest railroad company in the U.S., approximately 71% of locomotives are long-haul.125 The remainder are switchers. Best practice 2-1 is applicable to both long-haul locomotives and switchers. Best practices 2-2 and 2-3 are applicable only to switchers. Although best practice 2-2 has the potential to reduce

92

Air Conditioning System Improvement

1-7 1-8 1-9 1-10

0.33

0.31

C

1.83

1.88

0.39

0.41

C C

9.62 4.85

9.87 5.00

2.08 1.05

2.13 1.08

P

13.33

13.74

2.88

2.97

P

0.88

-f

0.88

-f

C

0.18

0.19

0.18

0.19

f

2.47

-

f

N

2.47

-

N

2.35

-f

2.35

-f

N

2.46

-f

2.46

-f


93

Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (1015 BTU) e

1-6

1.45

Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (106 Tons CO2 eq.) e

1-5

1.53

Percentage Contribution of a Subgroup to Total Reductions in Modal Energy Use (%)d

1-3 1-4

C

Percentage Contribution of a Subgroup to Total Reductions in Modal GHG Emissions (%)d

1-2 Anti-Idling

Off-Board Truck Stop Electrification Truck-Board Truck Stop Electrification Auxiliary Power Units Direct-Fired Heaters Direct-Fired Heaters with Thermal Storage Units Enhanced Air Conditioning System I - for Direct Emissions Enhanced Air Conditioning System II - for Indirect Emissions Alternative Refrigerants - CO2 Alternative Refrigerants HFC-152a Alternative Refrigerants - HC

Potential Reductions in Modal Energy Use (%)c

1-1

Brief Name of Best Practice

Potential Reductions in Modal GHG Emissions (%)c

I.D. No.

Potential Per-device Reductions in Energy Use (%)b

Subgroup

Potential Per-device Reductions in GHG Emissions (%)b

Potential Best Practices for the Truck Mode and the Estimated Reductions in GHG Emissions and Energy Use Developmental Status a

Table 9- 1.

3.64

4.50

15.00

0.19

4.65

0.40

19.15g

0.02

1-16 Tire Rolling Resistance Improvement Hybrid Propulsion Weight Reduction Transmission Improvement

1-17 1-18 1-19 1-20 1-21 1-22 1-23 1-24

1.43

1.47

C

2.37

2.44

2.37

2.44

C

1.24

1.28

1.24

1.28

N

4.62

4.76

2.17

2.24

N

8.01

8.26

3.76

3.88

C

2.37

2.44

0.43

0.44

C C C

0.78 2.83 2.83

0.80 2.91 2.91

0.56 2.03 2.83

0.58 2.10 2.91

N

1.15

1.19

0.54

0.56

N P P

40.27 4.62 0.97

41.52 4.76 1.00

3.40 4.62 0.97

3.50 4.76 1.00

C

0.97

1.00

0.92

0.95


94


1-15

1.96


1-14

1.90


1-13

C




1-12

Cab Top Deflector, Sloping Hood and Cab Side Flares Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Trailer or Van Leading and Trailing Edge Curvatures Pneumatic Aerodynamic Drag Reduction Planar Boat Tail Plates on a Tractor-Trailer Vehicle Load Profile Improvement Automatic Tire Inflation Systems Wide-Base Tires Low-Rolling-Resistance Tires Pneumatic Blowing to Reducing Rolling Resistance Hybrid trucks Lightweight Materials Advanced Transmission Transmission Friction Reduction through Low-Viscosity Transmission Lubricants


1-11


I.D. Brief Name of Best Practice No.


Subgroup

Developmental Status a

Table 9-1. Continued

16.17

19.98

66.56

0.83

6.88

8.50

28.33

0.35

5.95 8.10

7.36 10.00

24.50 33.32

0.30 0.41

3.31

4.10

13.64

0.17

a

b c d e f g h

1.81

1.86

C

3.73

3.85

3.07

3.16

P

5.49

5.66

5.49

5.66

C

4.62

4.76

0.82

0.85

N

6.35

6.54

5.22

5.38

C N

1.43 5.49

1.48 5.66

1.43 5.49

C

3.69

3.80

3.10

Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (1015 BTU)e

1.96

Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (106 Tons CO2 eq.)e

1.90


C



1-32 Truck Driver Training Program


Accessory Load Reduction Modifications in Driver Operational Practice

Engine Friction Reduction 1-25 through Low-Viscosity Engine Lubricants Increased Peak Cylinder 1-26 Pressures 1-27 Improved Fuel Injectors Turbocharged, Direct Injection to 1-28 Improved Thermal Management Thermoelectric Technology to 1-29 Recovery Waste Heat 1-30 Electric Auxiliaries 1-31 Fuel-Cell-Operated Auxiliaries


Diesel Engine Improvement



Subgroup



28.75

35.52

118.31

1.47

1.48 5.66

9.62

11.89

39.60

0.49

3.19

5.43

6.70

22.33

0.28

1-33 B20 Biodiesel Fuel for Trucks C 8.34 -8.30 4.27 -4.25 7.49 -8.92 30.81 -0.37 Total for the Truck h h 57.06 47.61 100.00 100.00 411.54 4.14 Mode Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now. Potential per-device reductions in GHG emissions or energy use are percentage reductions compared to GHG emissions (energy use) of a device without using this practice. Potential reductions in modal GHG emissions or energy use are estimated based on the difference in 2025 modal GHG emissions or energy use with and without the selected best practice divided by the total modal GHG emissions or energy use if no best practices are implemented. Percentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices. These reductions are estimated based on the difference between 2025 modal GHG emissions or energy use with and without implementation of the representative best practices of the subgroup.. These best practices reduce refrigerant leakage rate or use low GWP refrigerants. GHG emission reduction here are contributed by both energy use reduction and refrigerant leakage rate reduction or using low GWP refrigerants. Total potential reductions in GHG emissions and energy use exclude the reductions contributed by the strategies that are not the highest one in the cases of mutual exclusion.

95

a

b c d e f

2-6


60.90

3.43

0.042

0.44 4.76

24.25

53.98

3.05

0.038

4.00

4.00

20.38

45.36

2.56

0.032

5.50

-5.31

28.04

-60.24

3.52

-0.042

P

3.81

3.81

3.62

3.62

C

35.00

35.00

1.75

1.75

C C

11.50 4.76

8.80 4.76

0.58 4.76

P

4.00

4.00

N

8.60

-8.30

Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (106 Tons CO2 eq.) e Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (1015 BTU) e


2-5 Lubrication Improvement

27.34


Alternative Fuel

Combined Diesel Powered 2-1 Heating System and Auto Engine Start/stop System Battery-Diesel Hybrid Switching 2-2 Locomotive 2-3 Plug-In Units 2-4 Light Weight Materials


Weight Reduction Rolling Resistance Improvement



Anti-Idling

I.D. No.


Subgroup


Potential Best Practices for the Rail Mode and the Estimated Reductions in GHG Emissions and Energy Use Developmental Status a

Table 9- 2.

Total for the Rail 19.63f 8.82f 100.00 100.00 12.56 0.070 Mode Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now. Potential per-device reductions in GHG emissions or energy use are percentage reductions compared to GHG emissions (energy use) of a device without using this practice. Potential reductions in modal GHG emissions or energy use are estimated based on the difference in 2025 modal GHG emissions or energy use with and without the selected best practice divided by the total modal GHG emissions or energy use if no best practices are implemented. Percentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices. These reductions are estimated based on the difference between 2025 modal GHG emissions or energy use with and without implementation of the representative best practices of the subgroup.. Total potential reductions in GHG emissions and energy use for the rail mode exclude the reductions contributed by the strategies that are not the highest one in the cases of mutual exclusion.

96

per-vehicle GHG emissions more than the other two best practices, it is only applicable to switchers, which are estimated to account for only 5% of total locomotive fuel use.117 Best practice 2-1 has a larger over-all impact even though the per locomotive reduction is not as large, because it can be applied to all locomotives. The two most important subgroups for GHG emissions reduction are alternative fuel (I.D. No. 2-6) and anti-idling (I.D. Nos. 2-1 to 2-3). These two subgroups both contribute 28 and 27 percent, respectively, to the estimated total reduction in modal GHG emissions. 9.3

Air Mode

Table 9-3 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practices for the air mode. These reductions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, aerodynamic drag reduction (I.D. Nos. 3-1 to 3-4), includes two best practices that are mutually exclusive. Blended winglet (I.D. No. 3-3) and spiroid tip (I.D. No. 3-4) are mutually exclusive because both of these best practices are designed to reduce lift-induced drag and cannot both be implemented on the same airplane. The reductions by the former are estimated to be higher than the reductions by the latter. Therefore, the former is used as the basis for the analysis. The two most important subgroups for GHG emissions reduction are engine improvement (I.D. No. 3-10) and aerodynamic drag reduction (I.D. Nos. 3-1 to 3-4). These two subgroups contribute 38 and 28 percent, respectively, to the estimated total modal GHG emissions reductions. 9.4

Water Mode

Table 9-4 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practices for the water mode. These reductions are summarized in four ways, which are the same as those for Table 9-1. A subgroup, propeller system improvement (I.D. Nos. 4-1 to 4-3), includes best practices that are mutually exclusive. Each of them are based on different propeller designs. They cannot be implemented simultaneously on the same ship. To provide an upper bound on the potential benefits of this subgroup, the best practice that has the largest estimated reductions in fuel use and GHG emissions is selected as the basis for the analysis of modal reductions. The selected best practice is an auxiliary free-rotating propulsion device behind the main propeller.

97

1.60

1.60

1.60

N

6.00

6.00

6.00

6.00

C P

2.00 1.65

2.00 1.65

2.00 1.65

2.00 1.65

N

6.00

6.00

6.00

N N

2.00 1.00

2.00 1.00

2.94

2.94


1.60


Ground Support Equipment Improvement

P


Weight Reduction

3-1 Surface Grooves Hybrid Laminar Flow 3-2 Technology 3-3 Blended Winglet 3-4 Spiroid Tip Air traffic Management 3-5 Improvement 3-6 Airframe Weight Reduction 3-7 Non-Essential Weight Reduction Ground-Based Equipment as an 3-8 Alternative to Auxiliary Power Units Electric or Hybrid Heavy Duty 3-9 Delivery Trucks


Air Traffic Management




I.D. No.


Subgroup


Potential Best Practices for the Air Mode and the Estimated Reductions in GHG Emissions and Energy Use


Table 9- 3.

27.79

27.79

5.66

0.059

6.00

17.37

17.37

3.54

0.037

2.00 1.00

2.00 1.00

8.69

8.69

1.77

0.018

2.94

2.94

8.51

8.51

1.73

0.018

P P


98

a

b c d e f



C

13.00

13.00

13.00

13.00

37.64

37.64



Improved Engine Overall Efficiency


Engine Improvement 3-10




Subgroup



7.66

0.079

Total for the Air 34.54f 34.54f 100.00 100.00 20.35 0.211 Mode Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now. Potential per-device reductions in GHG emissions or energy use are percentage reductions compared to GHG emissions (energy use) of a device without using this practice. Potential reductions in modal GHG emissions or energy use are estimated based on the difference in 2025 modal GHG emissions or energy use with and without the selected best practice divided by the total modal GHG emissions or energy use if no best practices are implemented. Percentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices. These reductions are estimated based on the difference between 2025 modal GHG emissions or energy use with and without implementation of the representative best practices of the subgroup.. Total potential reductions in GHG emissions and energy use for the air mode exclude the reductions contributed by the strategies that are not the highest one in the cases of mutual exclusion.

99

a

c d e f

1.50 2.00

1.50 2.00

C

6.00

6.00

3.00

3.00

P

13.00

-3.20

0.16

-0.04


3.00 4.00


3.00 4.00


C C


4-1 Off-Center Propeller 4-2 Propeller Boss Cap with Fins Auxiliary Free-Rotating 4-3 Propulsion Device behind the Main Propeller Shoreside Power for Marine 4-4 Vessels at Ports 4-5 B20 Biodiesel Fuel for Ships


Anti-Idling



Propeller System Improvement

I.D. No.


Subgroup


Potential Best Practices for the Water Mode and the Estimated Reductions in GHG Emissions and Energy Use Developmental Status a

Table 9- 4.

68.44

174.93

3.65

0.043

3.71

-2.33

0.20

> -0.001

Alternative Fuel N 8.14 -8.30 1.22 -1.25 27.85 -72.59 1.48 -0.018 Total for the Water f f 4.38 1.72 100.00 100.00 5.33 0.025 Mode Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now.b Potential per-device reductions in GHG emissions or energy use are percentage reductions compared to GHG emissions (energy use) of a device without using this practice. Potential reductions in modal GHG emissions or energy use are estimated based on the difference in 2025 modal GHG emissions or energy use with and without the selected best practice divided by the total modal GHG emissions or energy use if no best practices are implemented. Percentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices. These reductions are estimated based on the difference between 2025 modal GHG emissions or energy use with and without implementation of the representative best practices of the subgroup.. Total potential reductions in GHG emissions and energy use for the water mode exclude the reductions contributed by the strategies that are not the highest one in the cases of mutual exclusion.

100

The two most important subgroups for GHG emissions reduction are propeller system improvement (I.D. Nos. 4-1 to 4-3) and alternative fuel (I.D. No. 4-5). These two subgroups contribute 68 and 28 percent, respectively, to the estimated total modal GHG emissions reductions. 9.5

Pipeline Mode

GHG emissions reductions for the pipeline mode are based upon energy use reductions, which include petroleum fuel use reductions and natural gas emission reductions. Table 9-5 summarizes potential individual and aggregate reductions in GHG emissions and energy use for best practices for the pipeline mode. These reductions are summarized in four ways, which are the same as those for Table 9-1. The most important subgroup for GHG emissions reduction is connecting method (I.D. Nos. 5-3). This subgroup contributes 44 percent to the estimated total modal GHG emissions reductions. 9.6

Intermodal Comparisons The purpose of this section is to summarize and discuss: •

comparisons of total reductions in relative and absolute modal GHG emissions in 2025 for multiple best practices for all modes;

•

annual reductions in modal GHG emissions, energy use reduction, and cost-effectiveness of selected best practices for which there is sufficient information for quantitative analysis; and

•

impacts of intermodal substitutes if intermodal shifts are available.

9.6.1 Total Modal GHG Emissions Reductions Modal GHG emissions reductions in this section are estimated based on the difference between 2025 modal emissions with or without implementation of the representative best practices. There is substantial variability among the best practices in terms of their potential percentage reductions in modal GHG emissions. The variations in reductions among individual practices range from 0.2 to 5.5 percent for the truck mode, 0.6 to 5.5 percent for the rail mode, 1.0 to 13.0 percent for the air mode, 0.2 to 3.0 percent for the water mode, and 0.1 to 1.9 percent for the pipeline mode. The average reductions for a best practice are 2.2, 3.4, 2.3, 1.6, and 0.9 percent for the truck, rail, air, water, and pipeline modes, respectively.

101

a

b c d e

0.50

0.13

C

90.00

90.00

0.57

0.16

C C C

1.93 0.11 1.32

0.54 0.02 0.37

1.93 0.07 1.32

0.54 0.02 0.37

Potential Aggregate Energy Use Reduction in 2025 for Each Subgroup (1015 BTU)e

9.02

Potential Aggregate GHG Emission Reduction in 2025 for Each Subgroup (106 Tons CO2 eq.)e

10.00


5-3 “Hot Tap” Method 5-4 Transfer Compression 5-5 Inline Inspection

C


Maintenance

Convert Natural Gas Pneumatic Controls to Instrument Air Replace High-Bleed Natural Gas 5-2 Pneumatic Devices with Low-Bleed Pneumatic Devices

5-1


Connecting Method




I.D. No.


Subgroup


Potential Best Practices for the Pipeline Mode and the Estimated Reductions in GHG Emissions and Energy Use


Table 9- 5.

24.52

23.64

1.40

0.003

43.83

44.35

2.50

0.005

31.65

32.01

1.81

0.004

Total for the Pipeline 4.40 1.22 100.00 100.00 5.70 0.011 Mode Developmental status: N = new concepts; P = pilot tests; C = commercially available systems. New concepts include basic research activities, applied research activities, and experiments at laboratory level. Pilot tests include testing prototype vehicles and demonstration projects. Commercially available systems can be purchased or implemented now. Potential per-device reductions in GHG emissions or energy use are percentage reductions compared to GHG emissions (energy use) of a device without using this practice. Potential reductions in modal GHG emissions or energy use are estimated based on the difference in 2025 modal GHG emissions or energy use with and without the selected best practice divided by the total modal GHG emissions or energy use if no best practices are implemented. Percentage contribution of a subgroup to total reductions is defined by dividing the percentage reductions for a subgroup by total modal reductions for all best practices. These reductions are estimated based on the difference between 2025 modal GHG emissions or energy use with and without implementation of the representative best practices of the subgroup..

102

Within each mode, multiple best practices can be applied simultaneously to achieve total 2025 modal GHG emissions reductions (compared to projected emissions if no best practices are used) of 57, 19, 34, 4, and 4 percent for the truck, rail, air, water, and pipeline modes, respectively, depending on the mode, as summarized in Figure 9-1 (a) and (b), which illustrate modal percentage reductions categorized by developmental status and target GHGs, respectively. N2O emission is not included because its contribution is less than 0.4% of total GHG emissions. The truck mode is the biggest GHG emissions contributor, and it also has the highest GHG emissions reduction potential. The truck mode is estimated to contribute 66 percent of freight transportation GHG emissions in 2025 if none of the best practices are adopted. The total GHG emissions of this mode in 2025 are estimated to increase 67 percent over 2003 levels. If all identified best practices are implemented aggressively, 2025 GHG emissions could be reduced by as much as 28 percent compared to 2003 levels. Furthermore, such reductions would amount to a 57 percent reduction compared to 2025 GHG emissions if none of the best practices are used. Each of the other four modes is estimated to contribute 12 percent or less to total freight GHG emissions in 2025. If no best practices are implemented, modal GHG emissions in 2025 from the rail, air, water, and pipeline modes are estimated to increase 49, 65, 28, and 15 percent, respectively, compared to 2003 levels. If all identified best practices are implemented aggressively, 2025 GHG emissions could increase by 20, 8, 22, and 9 percent, respectively, compared to 2003 levels, which is a smaller increase. If all identified best practices are implemented aggressively, 2025 GHG emissions could be reduced by 19, 34, 4, and 4 percent, respectively, compared to 2025 GHG emissions if none of the best practices are used. The magnitude of the estimated potential GHG emissions reductions for each mode in 2025 ranges from approximately 5 million to 412 million tons CO2 eq., as summarized in Figure 9-2. The magnitude of the estimated potential GHG emissions reductions for the truck mode in 2025 is significantly higher than for any of the other four modes. Both the total relative and absolute modal 2025 GHG emissions reductions possibilities for the truck mode are significantly higher than for the other four modes. The truck mode currently contributes more than 60 percent of total energy use and GHG emissions in freight transportation. There are more research and development programs focusing on the truck mode. Furthermore, an individual strategy for this mode can achieve higher absolute reductions even if the percentage reduction is comparable to that of best practices in other modes. For example, anti-idling practices for the truck mode are estimated to reduce truck mode GHG emissions by 2.1%. Anti-idling practices for the rail mode are estimated to reduce rail mode emissions by 5.4%. However, the magnitude of the truck model GHG emissions reductions is several times of the magnitude of the rail mode reductions, even though the percentage reduction is smaller. 103

60

GHG Emissions Reductions (%)

New Concepts 50

Pilot Tests Commercially Available Systems

40

30

20

10

0 Truck

Rail

Air

Water

Pipeline

(a) Categorized by Developmental Status

GHG Emissions Reductions (%)

60 HFC

50 40

CH4

30

CO2

20 10 0 Truck

Rail

Air

Water

Pipeline

(b) Categorized by Target GHGs Figure 9- 1. Total Modal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Multiple Best Practices in Each Mode

104

450

New Concepts

GHG Emissions Reductions (Million Tons CO2 eq.)

400

Pilot Tests

350

Commercially Available Systems 300 250 200 150 100 50 0 Truck

Rail

Air

Water

Pipeline

Figure 9- 2. Magnitudes of the Total Modal 2025 GHG Emissions Reductions Based on Simultaneous Implementation of Multiple Best Practices for Each Mode 9.6.2 Comparisons of Best Practices Whose Costs Are Assessed Quantitatively Current available cost information for best practices whose costs are not sufficient to be assessed quantitatively is summarized in simplified summary tables in Appendices. It is critical to have cost data for quantitative assessments. While it is clear that many best practices will not be considered by potential adopters until adequate cost data is available upon which to estimate costs reliably, at this time insufficient data are available to characterize costs reliably for most of the best practices identified here. Thus, there is a critical need for future work to better characterize these costs. To date, sufficient information has been obtained to assess 13 best practices quantitatively. Table 9-6 provides quantitative estimates of reductions in 2025 modal GHG emissions and energy use, as well as regarding costs. There is substantial variability among these 13 best practices in terms of annual reductions in modal 2025 GHG emissions and energy use within their individual modes, which is compared to 2025 GHG emissions and energy use without using these best practices. Three best practices for the truck mode, which include auxiliary power units, hybrid trucks, and B20 biodiesel, have the potential to achieve substantial GHG emissions reductions (15×106 ton CO2 eq./year or more). Two best practices for the truck mode, auxiliary power units and hybrid trucks, also have the potential to reduce energy use substantially, by 185×1012 BTU or more. 105

Water 4-5

5-1

Pipeline 5-2

5-3 “Hot Tap” Method

Battery Diesel Hybrid Switching Locomotive

2-6

Replace High Bleed Natural Gas Pneumatic Devices with Low Bleed Pneumatic Devices

Combined Diesel Powered Heating System and Auto Engine Start/Stop System

2-3

Convert Natural Gas Pneumatic Controls to Instrument Air

Rail 2-2

B20 Biodiesel

2-1

B20 Biodiesel

1-33

Plug-In Unit

1-21

B20 Biodiesel

Truck 1-4

Hybrid Trucks

1-3

Direct Fire Heaters

Practice Name

1-1


Mode I.D. No.

Quantitative Summary of Reductions in GHG Emissions, Energy Use, and Costs of Selected Best Practices a

Off-Board Truck Stop Electrification

Table 9- 6.

Annual GHG Emissions Reductions 2.4 15.0 7.6 24.5 30.8 2.3 1.1 0.4 3.5 1.5 0.7 0.8 2.5 (106 ton CO2 eq./year) Annual Energy Use Reduction 27 185 94 300 -370 29 14 4 -42 -18 1 2 5 (1012 BTU /year) Unit GHG Emissions Reductions 11 66 34 130 29 2.0 1.0 0.3 3.0 5.0 3.4 3.9 13 (10-3 lb CO2 eq./ton-mile) Unit Energy Use Reduction 60 409 207 804 -176 12 6 2 -18 -31 3 4 13 (BTU /ton-mile) 6 Annualized Cost ($10 /year) 570 3000 390 2430 3300 140 180 91 380 180 1.7 1.8 11 Annual Energy Cost Saving 900 3400 1740 5600 0 530 260 230 0 0 13 15 51 ($106/year) 6 Net Saving ($10 /year) 330 440 1350 3190 -3300 390 70 135 -380 -180 12 13 40 Net Savings per Unit of GHG 138 29 178 130 -108 167 65 364 -109 -120 18 18 16 Emissions Reductions ($/ton CO2 eq.) Net Savings per Unit of Energy Use 12 2.3 14 10.6 N/A b 13.5 5.2 38 N/A b N/A b 9.6 8.8 7.8 Reduction 6 ($/10 BTU) Simple Pay- back period (years) N/A c 3.2 0.6 2.1 N/A d 2.1 5.5 0.8 N/A d N/A d 0.3 0.9 0.2 a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. c There is no pay-back period for this best practice because there is no initial capital cost to uses. d There is no pay-back period for this best practice because there is no net saving.

106

There is substantial variability among these 13 best practices regarding their net cost savings. Ten best practices produce net cost savings. Many of these have very high capital costs, annual costs, or both but these are offset by even greater savings, typically for reduced fuel cost savings. For three of the best practices, the net savings are negative. Thus, these practices do not pay for themselves. These three practices, based on the use of B20 biodiesel, have a net increase in total costs because the fuel cost is higher than that for petroleum diesel, based on current typical experience. There is substantial variability among these 13 best practices regarding their cost-effectiveness. The top three most cost-effective best practices are: plug-in units for the rail mode; direct-fired heaters for the truck mode; and combined diesel powered heating system and auto engine start/stop system for the rail mode. The least cost-effective best practices are B20 biodiesel for the truck, rail and water modes. The variability of fuel prices, capital costs and operation and maintenance costs strongly impacts the accuracy of the cost-effectiveness results. Volatile fuel prices could cause the practices that do not correctly pay for themselves to produce net cost savings. For example, if diesel fuel price is reduced by 12%, the net savings of auxiliary power units for the truck mode would be negative. Changes in capital cost, such as an expected decrease over time in the capital cost for hybrid trucks, could cause practices that do not yet pay for themselves to produce a net cost saving. If petroleum oil prices continue to increase, it is possible that biodiesel fuel price might become lower than petroleum diesel fuel price, in which case the use of B20 Biodiesel might produce a net cost saving. There is substantial variability among these 13 best practices regarding their simple pay-back periods. Eight best practices have simple pay-back periods of less than 5 years, and five among these seven practices have simple payback periods of a year or less. One best practice produces a net savings but has no pay-back period because there is no initial capital cost. There is no pay-back period for the three best practices because they do not produce a net saving. From a national policy perspective, consideration of the potential magnitude of reductions is important. From an individual owner or operator perspective, consideration of cost savings and cost effectiveness may tend to be more important. 9.6.3 Intermodal Substitutions Intermodal shifts, such as from modes with high emissions per unit of freight transport (e.g., airplanes and trucks), to lower-emission modes, such as rail and sea-going ships, are attractive options for GHG emissions reductions, if feasible. The typical unit GHG emissions per unit of freight activity of each of these modes range from 0.06 to 2.16 lb CO2 per ton-mile, as illustrated in Figure 9-3. For example, the GHG emissions per ton-mile for rail are only 8 percent of those for trucks, implying a maximum GHG emissions reduction of 92 percent if rail 107

GHG Emissions per Unit of Freight Transport (lb CO2 eq. per ton-mile)

2.5 2.0 1.5 1.0 0.5 0.0 Truck Figure 9- 3.

Rail

Air

Water

Pipeline

Estimated GHG Emissions per Unit of Freight Transport of Each Mode

could substitute completely for trucking. The GHG emissions per ton-mile for ships are only 17 percent those of trucks, implying a maximum GHG emissions reduction of 83 percent if ships could substitute completely for trucking. There have been some recent evaluations of the effectiveness of inter-modal shifts as a GHG emissions reduction strategy. A Germany mail-order company reduced its annual CO2 emissions by 40% from 1993 to 1999, based on substituting sea-going ships for truck and air transport.126 For example, five percent of its consignments were transported by ship instead of truck in its Turkish market, and led to a savings of 0.16 tonnes of CO2 per tonne of merchandise. Furthermore, eight percent of air freight in the Hong Kong market was shifted to a combined sea-air transportation sequence, leading to reductions of 2.8 tonnes of CO2 per tonne of merchandise. A Canadian study estimated that a shift of one-third of truck freight to rail could decrease emissions by 19% between 2000 and 2010 in Ontario. This analysis was based on both vehicle and fuel cycle emissions.127 However, whether freight can be shifted from trucks to rail or ships may depend on a number of factors. These factors include distance, availability of infrastructure (e.g., port terminals, rail/truck intermodal facilities), size of the cargo, schedule, durability of the cargo, relative costs,127 and the need for new logistics systems.126 For example, some amount of truck activities, such as pick up and delivery, are likely to be needed even if most of the ton-miles involved rail,. According to one estimate, seven percent of the freight ton-miles require 108

shipment by truck for pick up and delivery, with the balance shipped by rail.128 For this scenario, the rail-truck inter-modal shift would reduce GHG emissions by approximately 85 percent, instead of the maximum possible 92 percent. Of course, the actual reductions are also affected by implementation of best practices for GHG reduction in both the truck and rail modes, which can lead to a differing percentage difference for the inter-modal shift. Thus, whether one mode of shipping can be a substitute for another depends on site-specific characteristics, and system-level intermodal analysis will be needed.

109

10.0. CONCLUSIONS AND RECOMMENDATIONS The purpose of the guidebook is to identify and characterize potential best practices for reducing energy use and refrigerant use in freight transportation, which could lead to reductions in GHG emissions. Some best practices for which sufficient information is available are assessed quantitatively based on several criteria. There is a lack of quantitative data for most of the identified best practices, and these best practices are assessed qualitatively. This research represents a “first step” in identifying best practices in the freight industry. Qualitative assessments are accompanied by preliminary estimates of overall reductions based on various assumptions that are detailed in the appendices. This Chapter presents key conclusions and recommendations. 10.1

Conclusions

If current trends continue, the increase in modal GHG emissions could range from 15 to 67 percent from 2003 to 2025, depending on the mode. If best practices are aggressively implemented, it is possible to achieve a net decrease in total GHG emissions and energy use, even if intermodal substitutions (e.g., truck to rail) do not occur. Even larger percentage reductions are possible if intermodal shifts are encouraged, particularly away from trucking and air and toward rail and water-borne modes. Of course, as best practices are implemented that reduce GHG emissions from each mode, the relative reduction associated with inter-modal shifts will also change. Many best practices are in early stages of development or commercialization. Therefore, there is limited cost data upon which to assess these best practices quantitatively. For thirteen best practices for which adequate cost data are available for quantitative assessment, the modal reductions in GHG emissions and energy use were highly variable. The normalized cost savings per unit of GHG emissions reduction was also highly variable. Ten of these practices offer net cost savings, while three of them have net cost increases. There is also substantial variability regarding the simple pay-back periods of best practices that have net savings. However, five of them have simple payback periods of a year or less. Governments and individual owners or operators should carefully identify and compare their options. From a national policy perspective, some best practices, such as direct fired heaters and B20 biodiesel for trucks, offer greater potential for large magnitudes in reduction of total GHG emissions, but may not be as cost-effective. There may be targeted opportunities for the Federal government to promote research and development of such options in order to reduce 110

their costs or to provide other incentives for their adoption. Of course, consideration must be given to co-benefits or adverse consequences of any given policy option. From an individual owner or operator perspective, consideration of cost savings and cost effectiveness may tend to be more important. Some best practices may be a “no regrets” proposition, in that the owner or operator can realize a net cost savings. This guidebook makes no recommendations about the use of specific strategies as best practices. Typically information regarding many best practices is incomplete and does not enable situation-specific assessment and comparison. While it is clear that many best practices will not be considered by potential adopters until adequate cost data is available upon which to estimate costs reliably, at this time insufficient data are available to characterize costs reliably for most of the best practices identified here. Potential best practices assessed qualitatively can be assessed quantitatively after sufficient information is available for quantitative assessment. Potential best practices assessed quantitatively can be further analyzed taking into account the variability or uncertainty of key assumptions, such as market penetration rates, fuel prices, discount rates, capital costs, and operation and maintenance costs. 10.2

Recommendations for Future Research Needs

To further inform decisions regarding adoption of suitable best practices, the following work is recommended: (1) Update information Many technologies are currently in the developmental stage and there is not sufficient information available yet for quantitative assessments. There is a critical need for future work to better characterize the costs data. Information given here may be updated as new information becomes available. (2) Revise or Develop Cost Estimates as New Data Become Available In this work, costs could be assessed for only 13 best practices. However, potential adopters of best practices need cost data for all of the possible best practices that could be applied to their situation. Thus, there is a critical need for more cost information. Ongoing work is recommended to obtain or develop cost estimates for best practices for which costs are not reported here, as well as to update cost estimates reported here as new data become available. (3) Evaluate key assumptions and other factors that influence the selection of best practices The impact of variations of key assumptions, such as market penetration rates, fuel prices, capital costs, and operation and maintenance costs, may be assessed via 111

sensitivity analysis. It is also important to understand the impacts of other factors, such as: the applicability and practical barriers of new technologies; policies and regulations; governmental incentives, such as financial, data, and analytical support, and costs and benefits seen by operators versus overall national reductions. (4) Develop tools to support decision making regarding best practices i. Develop a web-based decision tree: A decision tree is helpful when faced with a complex multistage decision problem. Thus, a decision tree is a useful tool to help inform decision making regarding the choice of best practices. A decision tree involves a hierarchical cascade of questions to guide responsible and target parties toward promising best practices appropriate to their situations. Decision trees include choice nodes, uncertainty nodes, and valuation. Choice nodes represent discrete actions that can be taken by a decision maker. Uncertainty nodes represent the range of possible outcomes associated with a particular decision option. Decisions can be made in a sequence, leading to a complete design for vehicle or modal technology and operations. The value of each alternative strategy can be quantified in a multiple attribute framework, including monetized attributes (e.g., cost savings) and non-monetized attributes (e.g., percentage reduction in energy use, emissions). The decision tree may be implemented in an interactive web-based format and could be publicly accessible. ii. Develop a decision tool Conditions of a specific responsible or target party, such as local fuel costs are critical considerations in choosing a best practice to adopt. Therefore, there is a critical need to develop a decision support that will allow such parties to compare multiple best practices on the basis of representative and relevant important assumptions. For such a tool, a user should be able to enter his or her own data and assumptions.

112

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128. Caceres, J. and D. Richards (2002). “Secure, Efficient and Sustainable Trade under NAFTA,” Proceedings of the 37th Annual Conference of Canadian Transportation Research Forum, Newfoundland, Canada, pp. 501-515. 129. Gaines, L. (2004), “Truck Idling: Implications and Solutions,” Argonne National Laboratory, presented at Alternatives to Truck Engine Idling Workshop, Des Moines, Iowa, June 22-23, Sponsored by the Iowa Energy Center and the Iowa State University Center for Transportation Research and Education, http://www.ctre.iastate.edu/pubs/truck_idling/ (Access 11/25/05). 130. Van den Berg, A.J. (1996), “Truckstop Electrification: Reducing CO2 Emissions from Mobile Sources While They are Stationary,” Energy Conversion and Management, 37(6-8):879-884, August. 131. Frey, H.C. and K. Kim (2005), “Operational Evaluation of Emissions and Fuel Use of B20 Versus Diesel Fueled Dump Trucks,” HWY 2004-18, Prepared by Department of Civil Engineering at North Carolina State University for North Carolina Department of Transportation, Raleigh, NC, September 30. 132. EERE, “Alternative Fuels: General Table of Fuel Properties,” Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy, Washington, DC, http://www.eere.energy.gov/afdc/altfuel/fuel_properties.html (Accessed 11/25/05). 133. EIA (2006), “Annual Energy Review 2005,” DOE/EIA-0384(2005), Energy Information Administration, Department of Energy, Washington, D.C., July 27, http://www.eia.doe.gov/emeu/aer/pdf/aer.pdf (Accessed 1/17/06). 134. EPA (2006), “EPA SmartWay Transport Partnership – Idle Reduction Technologies,” U.S. Environmental Protection Agency, August 11th, http://www.epa.gov/otaq/smartway/idlingtechnologies.htm (Accessed 10/13/06). 135. Cheryl Bynum (2007), Presented in Talking Freight – Strategies to Reduce Greenhouse Gas Emissions from Freight Transportation Seminar, Federal Highway Administration, 130

Department of Transportation, Washington, D.C., January 17, http://www.ops.fhwa.dot.gov/freight/fpd/talking_freight.htm (Accessed 1/17/07). 136. ATRI (2006), “Idle Reduction Technology: Fleet Preferences Survey,” Prepared by the American Transportation Research Institute, Alexandria, VA for New York State Energy Research and Development Authority, Albany, NY, February, http://www.westcoastdiesel.org/files/sector-trucking/fleet-preferences-survey.pdf (Accessed 1/18/07). 137. OPIS (2005), “Fuel Ethanol & Biodiesel Report: Volume 2, Issue 18,” Oil Price Information Service, Rockville, MD, May 2, http://www.opisnet.com/news/sample/ethanol.pdf (Accessed 01/14/06). 138. BNSF (2004), “Two-tech Fuel Cost Taming,” Railway Age, 205(7):26, July. 139. Gaines, L. (2005), “Heavy Vehicle Idling Reduction,” Presented at NASEO Annual Meeting, New York, NY, September 13, http://www.naseo.org/events/annual/2005/presentations/Gaines.pdf (Accessed 1/20/07). 140. EIA (2006), “Electric Power Annual 2005,” DOE/EIA-0348(2005), Energy Information Administration, Department of Energy, Washington, D.C., November, http://www.eia.doe.gov/cneaf/electricity/epa/epa.pdf (Accessed 1/20/07). 141. MARAD (2005), “U.S. Waterborne Foreign Trade Statistics: U.S. Waterborne Commerce,” Maritime Administration of US Department of Transportation, Washington, DC, April 7, http://www.marad.dot.gov/Marad_Statistics/WBC_1983_2003.pdf (Accessed 6/23/06). 142. BTS (2005), “National Transportation Statistics 2005: Water Transport Profile”, Bureau of Transportation Statistics of U.S. Department of Transportation, Washington, DC, April, http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_water_t ransport_profile.html (Accessed 6/23/06). 143. UNCTAD (2005), “Review of Maritime Transport, 2005,” UNCTAD/RMT/2005, United Nations Conference on Trade and Development, Geneva, Switzerland, July, http://www.unctad.org/en/docs/rmt2005_en.pdf (Accessed 6/23/06). 131

144. Corbett, J. J. (2004), “Marine Transportation and Energy Use,” Encyclopedia of Energy, 3: pp. 745-758, Elsevier Inc., San Diego, CA. 145. EIA, “Energy Calculator - Common Units and Conversions,” U.S. Energy Information Administration, Washington, DC, http://www.eia.doe.gov/kids/energyfacts/science/energy_calculator.html#natgascalc (Accessed 01/14/06). 146. HEI (2002), “Research Directions to Improve Estimates of Human Exposure and Risk from Diesel Exhaust: A Special Report of the Institute’s Diesel Epidemiology Working Group,” Health Effects Institute, Boston MA, April, http://www.healtheffects.org/Pubs/DieselSpecialReport02.pdf (Accessed 11/24/05). 147. EIA (2005), “Weekly Petroleum Status Report Glossary,” Energy Information Administration, Washington, DC, May, http://www.eia.doe.gov/pub/oil_gas/petroleum/data_publications/weekly_petroleum_status_r eport/current/pdf/glossary.pdf (Accessed 12/18/05). 148. Denton, J.E. (2004), “Used Oil in Bunker Fuel: A Review of Potential Human Health Implication,” California Environmental Protection Agency, December, http://www.oehha.ca.gov/risk/pdf/UsedOilInBunkerFuel.pdf (Accessed 01/11/06). 149. RTI International (2003), “Generic Verification Protocol for Determination of Emissions Reductions Obtained by Use of Alternative or Reformulated Liquid Fuels, Fuel Additives, Fuel Emulsions, and Lubricants for Highway and Nonroad Use Diesel Engines,” CR829434-01-1, Prepared by RTI International for U. S. Environmental Protection Agency, September, http://www.epa.gov/etv/pdfs/vp/05_vp_fuel.pdf (Accessed 11/24/05). 150. EIA “Energy Glossary,” Energy Information Administration, Washington, DC, http://www.eia.doe.gov/glossary/glossary_main_page.htm (Accessed 11/13/05). 151. NIBS, “Whole Building Design Guide: Standards Library: Federal and Military Specifications and Standards,” National Institute of Building Sciences, Washington, DC, 132

http://www.wbdg.org/ccb/index.php (Accessed 01/05/06). 152. US Naval Academy (2005), “Naval Applications of Chemistry: Fuels and Lubricants,” Chemistry Department, U. S. Naval Academy, Annapolis, MD, August 18, 2005, http://www.chemistry.usna.edu/navapps/pdf/fuels_01.pdf (Accessed 12/18/05). 153. ARAC (1998), “Fuel Properties - Effect on Aircraft and Infrastructure: Final Report,” Prepared by The Fuels Properties Task Group for the Fuel Tank Harmonization Working Group of the FAA Aviation Rulemaking Advisory Committee, Revised on July 15, http://www.fire.tc.faa.gov/pdf/TG67.pdf (Accessed 04/27/07). 154. NREL (2005), “Advanced Vehicles & Fuel Research: Advanced Fuels Properties Database,” National Renewable Energy Laboratory, Golden, CO, http://www.nrel.gov/vehiclesandfuels/fuels_database.html (Accessed 12/18/05). 155. Henderson, S. (2000), “Assessment of Net Emissions of Greenhouse Gases from Ethanol-Gasoline Blends in Southern Ontario,” R-2000-1, Prepared by Levelton Engineering Ltd. for Agriculture and Agri-Food Canada, Ottawa, Canada January, http://www.tc.gc.ca/programmes/environnement/changementclimatique/docs/ETOH-FNL-RP TAug30-1999.doc (Accessed 01/12/06). 156. AGA (2005), “Natural Gas Glossary,” American Gas Association, Washington, DC, http://www.aga.org/Content/NavigationMenu/About_Natural_Gas/Natural_Gas_Glossary/ (Accessed 12/18/05). 157. Tse, L. (2004), “Natural Gas Properties,” Vision Engineer Ltd., May 28, http://www.visionengineer.com/env/alt_ng_prop.php (Accessed 01/14/06). 158. EIA (2006), “Refiner Petroleum Product Prices by Sales Type: US Area,” U.S. Energy Information Administration, Washington, DC, January 5, http://tonto.eia.doe.gov/dnav/pet/pet_pri_refoth_dcu_nus_m.htm (Accessed 01/12/06). 159. EIA (2006), “Residual Fuel Oil Prices by Sales Type: US Area,” U.S. Energy Information Administration, Washington, DC, January 5, 133

http://tonto.eia.doe.gov/dnav/pet/pet_pri_resid_dcu_nus_m.htm (Accessed 01/12/06).

134

APPENDIX A.

DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR TRUCK MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 4, including the standardized reporting tables, if their corresponding best practices can be assessed quantitatively, or the simplified summary tables, if their corresponding best practices are assessed qualitatively. For those assessed quantitatively, the methods for the estimation of data in the standardized reporting tables are also described. Appendix A.1

Best Practice 1-1: Off-Board Truck Stop Electrification

This best practice is assessed quantitatively. Table A-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained. A.

Estimate of total number of vehicles or devices: (a)

Assumption:

i. Total number of trucks with sleeper cab is equal to the number of trucks having conventional cab with sleeper plus the number of trucks having cab over engine with sleeper. ii. Total truck number in 2002 is equal to total truck number in 2003. iii. Annual per-truck energy use in 2025 is the same as annual per-truck energy use in 2003.

(b) Calculation:

i. The 2002 Vehicle Inventory and Use Survey reported that 568,600 trucks had conventional cab with sleeper, and 109,000 trucks had cab over engine with sleeper.18 Thus, there were 677,600 trucks with sleeper cab in 2003.

(568,600 trucks ) + (109,000 trucks ) = 677,600 trucks ii. Since per-truck energy use is the same and modal energy use are estimated to grow by 67% from 2003 to 2025,4 total truck number increases by 67% from 2003 to 2025. 677,600 trucks × (1 + 67%) = 1,131,500 trucks

135

Table A-1. Standardized Reporting Table for Best Practice 1-1, Off-Board Truck Stop Electrification.a Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description Off-Board Truck Stop Electrification Truck Anti-Idling 1, 2, 5, 13, 20, 21, 22 1, 2, 6, 8 CO2 Technology

Practice Goals

Developmental Status Practice Summary

Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER)

Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.33% (2.4 ×106 tons of CO2 eq.) and 0.31% (27.3 ×1012 Btu), respectively. C This practice enables truck drivers to switch off their base engines by connecting to a service module, which includes heating, air conditioning and electricity, at a truck stop. Unit Value 109 ton-miles/year 2,098 109 ton-miles/year

453

106 ton CO2 eq./year 1012 BTU /year lbs/year 10-3 lb CO2 eq./ton-mile BTU /ton-mile lbs/ton-mile

2.4 27.3 N/A 11

Unit Energy Use Reduction (UER) 60 Unit Refrigerant Use Reduction (URR) N/A Practice Costs Capital Cost ® 106 USD ($) N/A Discount Rate ® % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year-1 N/A Annual O & M Cost (AOM) $106 /year N/A Annualized Cost (AC) $106 /year 570 Annual Energy Cost Saving (AECS) $106 /year 900 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year 330 Net Savings per Unit of GHG Emissions Reductions $/ton CO2 eq. 140 (NSGR) 6 Net Savings per Unit of Energy Use Reduction (NSER) $/10 BTU 12 Net Savings per Unit of Refrigerant Use Reduction (NSRR) $/lb N/A Simple Payback Period (SPP) years N/Ab a These assessments are based on the assumptions that these best practices reach their potential 136

b

maximum market shares in 2025. There is no pay-back period for this best practice because there is no initial capital cost to uses.

(d) Results:

B.

Estimate of annual transport activity for the mode: (a)

C.

Assumption:

The growth rate of total transport activity is the same as the growth rate of energy use for the truck mode.

(b) 2003 Results:

The estimated total transport activity for the truck mode in the U.S. in 2003 is 1,256 ×109 ton-miles.3

(c)

Since total energy use for the truck mode is estimated to grow by 67% from 2003 to 2025,4 the estimated total transport activity for the truck mode in the U.S. in 2025 will be 2,098 ×109 ton-miles.

2025 Results:

Estimate of annual transport activity to which a practice is applicable: (a)

D.

There will be 1,131,500 trucks with sleeper cab in 2025.

Assumption:

The ratio of annual transport activity of trucks with sleeper cab to annual transport activity of all trucks is proportional to the ratio of energy use for trucks with sleeper cab to energy use for all trucks.

(b)

Calculation:

The ratio of energy use for trucks with sleeper cab to energy use for all trucks is 21.6% (1.125×1015 BTU vs. 5.21×1015 BTU).3

(c)

Results:

Since the ratio is 21.6%, the estimated total transport activity for the truck mode in the U.S. in 2025 will be 453 ×109 ton-miles.

Estimate of annual GHG emissions reductions: (a)

Assumption:

i. Total GHG emissions reductions are that GHG emissions reductions due to energy use reduction minus GHG emissions due to electricity use for operating this practice at truck stops. ii. Approximately 20% of trucks are idled at truck stops.129 iii. On an annual basis an average truck accumulates about 1,830

137

hours of parking idle,130 and one hour idle of a truck consumes 0.85 gallon of diesel fuel.27 (b)

Calculation:

i. Truck idle fuel use is 0.85 gal/hr, which is equal to 117,887 BTU/hr because that the estimated heating value of petroleum diesel is 138,690 BTU/gallon.131-132 ii. Total idle fuel use for trucks with sleeper cab in 2003 is estimated to be 1.46×108 (106 BTU) per year.  hrs 0.85 gallon 138,698 BTU   677,600 trucks × 1,830  × × trucks hr gallon   8 6 = 1.46 × 10 10 BTU

(

)

iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO2 eq. per 106 BTU.1 iv. Total GHG emissions reductions due to fuel use reduction are estimated to be 2.36×106 tons CO2 eq. in 2003.

(

)

1.46 × 108 106 BTU × 20% ×

0.0808 tons CO 2 eq. 106 BTU

6

= 2.36 × 10 tons CO 2 eq. v. Total energy output for IdleAire is 18,000 BTU/hr because that A/C or heater energy output average is 17,500 BTU/hr and other accessory consumes approximately 500 BTU/hr of energy. vi. GHG emissions coefficient for electricity is 0.0007 tons CO2 eq. per kWh.108 vii. Total GHG emissions due to electricity use are estimated to be 0.92×106 tons CO2 eq. in 2003.  0.0007 tons CO 2 eq.   677,600 trucks × 1,830 hrs × 18000 BTU × kWh ×    trucks hr 3412 BTU kWh   × 20% = 0.92 × 106 tons CO 2 eq.

viii. The estimated annual GHG emissions reductions are estimated to be 1.44×106 tons CO2 eq. in 2003. 138

(2.36 ×10

6

(c)

E.

Results:

)

− 0.92 × 106 tons CO2eq. = 1.44 × 106 tons CO2 eq.

Since GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Section 1.2, the estimated 2025 annual GHG emissions reductions are 2.41×106 tons CO2 eq.

Estimate of annual energy use reduction: (a)

Assumption:

i. Total energy use reduction is that energy use reduction minuses energy for producing electricity for operating this practice. ii. Approximately 20% of truck idling is at truck stops.129 iii. On an annual basis an average truck accumulates about 1,830 hours of parking idle,130 and one hour idle consume 0.85 gallon of diesel fuel.27

(b)

Calculation:

i. Truck idle fuel use is 0.85 gal/hr, which is equal to 117,887 BTU/hr because that the estimated heating value of petroleum diesel is 138,690 BTU/gallon.131-132 ii. Hourly electricity needed for producing electricity in order to operate this practice is 18,000 BTU/hr, including 17,500 BTU/hr for the average for operating A/C or heater and 500 BTU/hr for operating other accessory. iii. Since the ratio of primary energy input to electricity output is estimated to be 2.89 based on total electricity generated and total primary energy consumed in the U.S. in 2005,133 primary energy needed for producing electricity in order to operate this practice is 52,000 BTU/hr. iii. Since only 20% of trucks idle at truck stops, the suitable locations for this practice, the percentage of energy reduction for adopting this practice is estimated to be 11.2%.  117887 − 52000    × 20% = 11.2% 117887  

iv. Total energy use for trucks with sleeper cab at idle in 2003 is

139

estimated to be 1.46×108 (106 BTU) per year.  hrs 0.85 gallon 138,698 BTU   677,600 trucks × 1,830  × × trucks hr gallon   = 1.46 × 108 106 BTU

(

)

v. The estimated annual energy use reduction in 2003 is 1.63×107 (106 BTU).

(

)

(

)

1.46 × 108 106 BTU ×10.6% = 1.63 ×107 106 BTU

(c)

F.

Results:

Since total energy use for the truck mode is estimated to grow by 67%,4 the estimated annual energy use reduction in 2025 is 2.73×107 (106 BTU).

Estimate of unit GHG emissions reductions:  2.41 million tons CO 2 eq   2,000 lbs  0.011 lb CO 2 eq.  . ×   =  453 billion ton − miles   ton ton − mile   

G.

Estimate of unit energy use reduction:

(

)

 2.73 × 10 7 10 6 BTU  60.3 BTU  . =  453 billion ton − miles  ton − mile  

H.

Estimate of capital cost (Not available because of no initial cost for this practice)

I.

Estimate of annual O & M cost (Not available)

J.

Estimate of annualized cost: (a) Assumption: The price for hourly service of this practice, which is provided by IdleAire, is the average of its individual driver’s price and its contract price. (b)

Calculation:

i. The price for individual driver is $1.5/hr and the contract price is $1.25/hr. Thus, the average price is estimated to be $1.375/hr.5

140

ii. The estimated annualized cost in 2003 is $341×106.

hrs $1.375   6 × 20% ×  677,600 trucks × 1,830  = $341× 10 trucks hr   (c)

K.

Results:

Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, the estimated annualized cost in 2025 is $569 ×106.

Estimate of energy cost reduction: (a) Assumption: Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $2.56/gallon ( = $18.5/106 BTU).114 (b)

Calculation:

The estimated energy cost reduction in 2003 is $540 ×106.

(

)

1.46 × 108 106 BTU × 20% × (c)

L.

Results:

$18.5 = $540 × 106 6 10 BTU

Since total energy use is estimated to grow by 67% from 2003 to 2025, which is explained in Appendix A.1.A, the estimated energy cost reduction in 2025 is $902 ×106.

Estimate of net savings: $902 × 106 − $569 × 106 = $333 × 106

M.

Estimate of net savings per unit of GHG emissions reductions: $333 ×10 6 2.41×10 tons CO 2 eq. 6

N.

=

$138.2 ton CO 2 eq.

Estimate of net savings per unit of energy use reduction:

$333×10 6 $12.2 = 12 27.3 ×10 BTU 10 6 BTU O.

Estimate of simple payback period: (Not available because there is no initial capital cost for this practice). 141

Appendix A.2

Best Practice 1-2:

Truck-Board Truck Stop Electrification

This best practice is assessed qualitatively. Table A-2 summarizes the assessment results in the standardized simplified reporting table format. Table A-2. Simplified Summary Table for Best Practice 1-2, Truck-Board Truck Stop Electrification Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks

Truck-board Truck Stop Electrification Truck Anti-Idling 1, 2, 5, 6, 8, 11, 13, 20, 21, 22 1, 2,4, 6, 8 CO2 Technology

Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.39% and 0.41%, respectively. C This system enables truck drivers to switch off their diesel engines by connecting parked trucks to electrical outlets (receptacles) for electric powered on-board HVAC systems at a truck stop. 0.39% 0.41% N/A The operation charge for this system is $0.5~$1.00 per hour per truck Using electricity consumes less energy and emits less GHG than using diesel fuel for truck base engine. Trucks cannot use this alternative unless they are parked at a truck stop with this type of electrification system.

142

Appendix A.3

Best Practice 1-3:



Estimate of total number of vehicles or devices: Total number of vehicles is explained in Appendix A.1.A.

B.

Estimate of annual transport activity for the mode: Annual transport activity for the mode is explained in Appendix A.1.B.

C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is explained in Appendix A.1.C.

D.


Assumption:

i. Total GHG emissions reductions are due to energy use reduction. ii. On an annual basis an average truck accumulates about 1,830 hours of parking idle,130 and one hour idle of a truck consumes 0.85 gallon of diesel fuel.27 iii. The fuel rate for APU use is estimated to be 0.2 gallon of diesel fuel per hour.134

(b)

Calculation:

i. Idle fuel use is estimated to be 117,887 BTU/hr, explained in Appendix A.1.

143

Table A-3. Standardized Reporting Table for Best Practice 1-3, Auxiliary Power Units.a Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description Auxiliary Power Units Truck Anti-Idling 1, 2, 5, 6, 8, 11 1, 2, 4, 6 CO2 Technology

Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 20.8% (15.0 ×106 tons of CO2 eq.) and 2.13% (185 ×1012 Btu), respectively. C APUs are mounted externally on the truck cabs or sleepers that provide heat and A/C for the sleeper, heat for engine, and power for auxiliaries. They can avoid the need for idling of the truck base engines Unit Value 109 ton-miles/year 2,098

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is 453 109 ton-miles/year Applicable (ATAP) Annual GHG Emissions Reductions(AGR) 106 ton CO2 eq./year 15.0 Annual Energy Use Reduction (AER) 1012 BTU /year 185.0 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10-3 lb CO2 eq./ton-mile 66 Unit Energy Use Reduction (UER) BTU /ton-mile 409 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs Capital Cost (C) 106 USD ($) 9,400 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 5 Fixed Charge Factor (a) year-1 0.264 Annual O & M Cost (AOM) $106 /year 520 6 Annualized Cost (AC) $10 /year 2,990 Annual Energy Cost Saving (AECS) $106 /year 3,430 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A 6 Net Savings (NS) $10 /year 440 Net Savings per Unit of GHG Emissions Reductions 29 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 2.3 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 3.2 a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. 144

ii. Total fuel use reduction for this practice in 2003 is estimated to be 1.11×108 (106 BTU) per year.  hrs 0.85 gallon 138,698 BTU   677,600 trucks × 1,830  × × trucks hr gallon    0.85 − 0.2  8 6 ×  = 1.11 × 10 10 BTU  0.85 

(

)

iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO2 eq. per 106 BTU.1 iv. Total GHG emissions reductions due to fuel use reduction are estimated to be 8.97×106 tons CO2 eq. in 2002.

(

)

1.11 × 10 8 10 6 BTU ×

0.0808 tons CO 2 eq. 10 6 BTU

6

= 8.97 × 10 tons CO 2 eq.

(c)

E.

Results:

Since GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Section 1.2, the estimated 2025 GHG emissions reductions are 14.98×106 tons CO2 eq..

Estimate of annual energy use reduction: i. Fuel use reduction for this practice in 2003 is estimated to be 1.11×108 (106 BTU), explained in Appendix A.3.D. ii. Since energy use for the truck mode is estimated to grow by 67%,4 the estimated annual energy use reduction in 2025 is 1.85×108 (106 BTU).

F.

Estimate of unit GHG emissions reductions:  14.98 million tons CO 2 eq   2,000 lbs  0.066 lb CO 2 eq.  . ×   =  453 billion ton − miles   ton ton − mile   

145

G.


(

)

 1.85 × 10 8 10 6 BTU  408.96 BTU  . =  453 billion ton − miles  ton − mile  

H.

Estimate of capital cost i. The capital cost of an auxiliary power unit, which includes factory cost and installation cost, is estimated to be $8,279 per truck.31 Total capital costs of auxiliary power units for all trucks with sleeper cab in 2003 is estimated to be $5.6 ×109. $8,279 × 677,600 trucks = $4.8 × 10 9 = $5.6 × 10 9 truck

ii. Since the truck mode is estimated to grow by 67%, total capital costs of auxiliary power units for all trucks with sleeper cab in 2025 is estimated to be $9.4 ×109. I.

Estimate of annual O & M cost i. Annual maintenance cost of an auxiliary power unit per is estimated to be $460.51 Total annual maintenance costs of auxiliary power units for all trucks with sleeper cab in 2003 is estimated to be $312 ×106. $460 × 677,600 trucks = $3.12 × 10 8 = $312 × 10 6 truck

ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, annual O & M costs of auxiliary power units for all trucks with sleeper cab in 2025 is estimated to be $520 ×106.

J.

Estimate of annualized cost: i. The life-time of auxiliary power units is estimated to be 5 years.31 ii. Fixed charge factor is estimated to be 0.264. Fixed ch arg e factor (a ) =

1    1  ∑   i =1  (1 + 0.1)i      5

=

1 = 0.264 3.79

iii. ($9.4 billion × 0.264) + ($520 million) = $2.99 × 10 9 146

K.


Calculation:

The estimated energy cost reduction in 2003 is $2.05 ×109.

(

)

1.11 × 108 106 BTU × ×

(c)

L.

Results:

$18.5 = $2.05 × 109 6 10 BTU

Since total energy use for the truck mode is estimated to grow by 67% from 2003 to 2025,4 the estimated energy cost reduction in 2025 is $3.43 ×109.

Estimate of net savings: $3.43 ×10 9 − $2.99 ×10 9 = $438 ×10 6

M.

M.

Estimate of net savings per unit of GHG emissions reductions: $438 ×10 6

14.98 ×10 tons CO 2 eq. 6

N.

=

$28.99 ton CO 2 eq.


$438 ×10 6 $2.34 = 12 185 ×10 BTU 10 6 BTU

O.

Estimate of simple payback period:

$9.4 × 10 9 = 3.22 years $3.43 × 10 9 − $0.52 × 10 9

(

)

147

Appendix A.4

Best Practice 1-4:

Direct-Fired Heaters

This best practice is assessed quantitatively. Table A-4 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained.

A.

Estimate of total number of vehicles or devices: Total number of vehicles is explained in Appendix A.1.A.

B.


C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is explained in Appendix A.1.C.

D.


Assumption:

i. Total GHG emissions reductions are due to energy use reduction. ii. This practice is estimated to reduce fuel use for trucks with sleeper cab by 5%.135

(b)

Calculation:

i. Total energy used for trucks with sleeper cab is estimated to be 1.125×1015 BTU.3 ii. Total fuel use reduction for this practice in 2003 is estimated to be 5.63×1013 BTU per year.

1.125 × 1015 BTU × 5%0 = 5.63 × 1013 BTU iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO2 eq. per 106 BTU.1

148

Table A-4. Standardized Reporting Table for Best Practice 1-4, Direct-Fired Heaters.a Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description

Direct-Fired Heaters Truck Anti-Idling 1, 2, 5 1, 2, 4, 6 CO2 Technology

Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.05% (7.6 ×106 tons of CO2 eq.) and 1.08% (94 ×1012 Btu), respectively. C Direct-fired heaters can avoid the need for idling of truck base engines in cold weather. Heat is produced from diesel fuel combustion and transferred to a heat exchanger for sleeper cabs and engines. Unit Value 9 10 ton-miles/year 2,098

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is 453 109 ton-miles/year Applicable (ATAP) Annual GHG Emissions Reductions(AGR) 106 ton CO2 eq./year 7.6 12 Annual Energy Use Reduction (AER) 10 BTU /year 93.9 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10-3 lb CO2 eq./ton-mile 34 Unit Energy Use Reduction (UER) BTU /ton-mile 207 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs Capital Cost (C) 106 USD ($) 996 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 5 Fixed Charge Factor (a) year-1 0.264 Annual O & M Cost (AOM) $106 /year 125 Annualized Cost (AC) $106 /year 387 Annual Energy Cost Saving (AECS) $106 /year 1,740 6 Annual Refrigerant Cost Saving (ARCS) $10 /year N/A Net Savings (NS) $106 /year 1350 Net Savings per Unit of GHG Emissions Reductions 177.6 $/ton CO2 eq. (NSGR) 6 Net Savings per Unit of Energy Use Reduction (NSER) $/10 BTU 14.4 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 0.62 a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. 149

iv. Total GHG emissions reductions due to fuel use reduction are estimated to be 4.55×106 tons CO2 eq. in 2003.

(

)

5.63 × 10 7 10 6 BTU ×

(c)

E.

Results:

0.0808 tons CO 2 eq. 10 6 BTU

6

= 4.55 × 10 tons CO 2 eq.

Since total GHG emissions for the truck mode is estimated to grow by 67%, which is explained in Section 1.2, the estimated 2025 annual GHG emissions reductions are 7.60×106 tons CO2 eq.

Estimate of annual energy use reduction: i. Fuel use reduction for this practice in 2003 is estimated to be 56.3×1012 BTU, explained in Appendix A.4.D. ii. Since total energy use for the truck mode is estimated to grow by 67%,4 the estimated annual energy use reduction in 2025 is 93.9×1012 BTU.

F.

Estimate of unit GHG emissions reductions:  7.60 × 10 6 tons CO eq   2,000 lbs  0.034 lb CO eq. 2 2 . ×    =  453 × 10 9 ton − miles   ton ton − mile   

G.


(

)

 9.39 × 10 7 10 6 BTU  207.3 BTU  . = 9 ton − mile 453 × 10 ton − miles  

H.

Estimate of capital cost i. The capital cost of a direct-fired heater is estimated to be $3,200 in 1996,27 but it has been re-estimated to be $880 per truck in 2006.136 Total capital cost for all trucks with sleeper cab in 2003 is estimated to be $596.3 ×106.

150

$880 × 677,600 trucks = $596.3 × 10 6 truck

ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, total capital cost for all trucks with sleeper cab in 2025 is estimated to be $995.8 ×106. I.

Estimate of annual O & M cost i. The annual maintenance cost of a direct-fired heater is estimated to be $110 per truck.128 Total O & M cost for all trucks with sleeper cab in 2003 is estimated to be $74.5 ×106. $110 × 677,600 trucks = $74.54 × 10 6 truck

ii. Since total truck number is estimated to grow by 67%, which is explained in Appendix A.1.A, total O & M cost for all trucks with sleeper cab in 2025 is estimated to be $124.5 ×106.

J.

Estimate of annualized cost: i. The life-time is estimated to be 5 years.51 ii. Fixed charge factor is estimated to be 0.264. Fixed ch arg e factor (a ) =

(

1    1  ∑   i =1  (1 + 0.1)i      5

=

1 = 0.264 3.79

)

6 6 6 iii. $995.8 × 10 × 0.264 + $124.5 × 10 = $387.4 × 10

iv. The estimated of annualized cost in 2025 is 387.4×106.

K.


Calculation:

(

)

9.39 × 10 7 10 6 BTU × ×

151

$18.5 = $1.74 × 10 9 6 10 BTU

(c) L.

Results:

The estimated energy cost reduction in 2025 is $1.74 × 109.

Estimate of net savings: i. $1.74 × 109 − $0.39 × 109 = $1350 × 10 6 ii. The estimated net savings in 2025 is $1350 × 106.

M.

Estimate of net savings per unit of GHG emissions reductions: $1350 × 10 6 7.6 × 10 tons CO 2 eq. 6

N.

=

$177.6 ton CO 2 eq.


$1350 × 106 $14.4 = 93.9 × 1012 BTU 106 BTU O.

Estimate of simple payback period:

$0.996 × 10 9 = 0.62 years $1.74 × 10 9 − $0.125 × 10 9

(

)

152

Appendix A.5

Best Practice 1-5: Direct-fired Heaters with Thermal Storage Units

This best practice is assessed qualitatively. Table A-5 summarizes the assessment results in the standardized simplified reporting table format. Table A-5. Simplified Summary Table for Best Practice 1-5, Direct-Fired Heaters with Thermal Storage Units Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary

Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks

Direct-Fired Heaters with Thermal Storage Units Truck Anti-Idling 1, 2, 5, 16, 18, 19 1, 2, 4, 6 CO2 Technology

Goal is to have all trucks with sleeper cabs participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.88% and 2.97%, respectively. P The combination of direct-fired heaters and thermal storage units, which consists of a phase change material for storing heating or cooling energy, supplies heating and cooling, but no electrical power, to the sleeper compartment when the base engine is off. 2.88% 2.97% N/A N/A This system is probably the most energy-efficient anti-idling practice. The disadvantage of this practice is that it supplies no electricity, and requires power from the vehicle’s batteries.

153

Appendix A.6

Best Practice 1-6: Emissions

Enhanced Air Conditioning System I - for Direct

This best practice is assessed qualitatively. Table A-6 summarizes the assessment results in the standardized simplified reporting table format. Table A-6. Simplified Summary Table for Best Practice 1-6, Enhanced Air Conditioning System I - for Direct Emissions Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Enhanced Air Conditioning System I - for Direct Emissions Truck Air Conditioning System Improvement 1, 2, 4, 5, 6, 11, 18, 19 1, 2, 4, 6, 7 HFC Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions in 2025 would be 0.88%. P Enhanced air conditioning systems can reduce direct GHG emissions by reducing the leakage of HFC-134a. The refrigerant leakage rates can be decreased through the use of low permeable hoses, improved hose ends and connectors, and improved compressor shaft seals. 0.88% N/A 35.3% The incremental capital cost of this system is approximately $33 per truck. This system can reduce a lot of refrigerant leakage for the truck mode, and save the cost for recharge the refrigerant. Safety characteristics of this system have no change because the same refrigerant is used. There is not as yet a standard method for testing and certifying the leakage rate of an enhanced system is in the developmental stage.

154

Appendix A.7

Best Practice 1-7: Emissions

Enhanced Air Conditioning System II - for Indirect

This best practice is assessed qualitatively. Table A-7 summarizes the assessment results in the standardized simplified reporting table format. Table A-7. Simplified Summary Table for Best Practice 1-7, Enhanced Air Conditioning System II - for Indirect Emissions Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Enhanced Air Conditioning System II - for Indirect Emissions Truck Air Conditioning System Improvement 1, 2, 4, 5, 6, 11, 18, 19 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.18% and 0.19%, respectively. C Enhanced air conditioning systems for reducing indirect GHG emissions can decrease base engine load requirements from mobile A/C systems. This system replaces fixed displacement compressors (FDCs) with externally controlled variable displacement compressors (VDC), and uses improved control systems, and improved condensers and evaporators. 0.18% 0.19% N/A The incremental capital cost of this system is approximately $7 per truck. This system can reduce energy use for operating A/C, and save energy cost. The benefit of reducing engine load is only available in hot weather when the A/C system is used.

155

Appendix A.8

Best Practice 1-8:

Alternative Refrigerants - CO2

This best practice is assessed qualitatively. Table A-8 summarizes the assessment results in the standardized simplified reporting table format. Table A-8. Simplified Summary Table for Best Practice 1-8, Alternative Refrigerants - CO2 Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information

Benefits and Drawbacks

Alternative Refrigerants - CO2 Truck Air Conditioning System Improvement 1, 2, 4, 5, 6, 11, 16, 18, 19 1, 2, 4, 6, 7 HFC Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions in 2025 would be 2.47%. N The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas CO2 has GWP = 1. Therefore, CO2 is being investigated as an alternative refrigerant. 2.47% N/A 99.9% The incremental capital cost of CO2 air conditioning system is $42.5 per truck, including $20 for upgrading system hoses and components for higher pressure operating conditions and $22.5 for additional safety equipment. Thus, the incremental capital cost of CO2 may be increased to $70 per truck, including $20 for upgrading system and $50 for secondary loop designs. This system uses alternative refrigerant with very low GWP. Safety assessment and potential risk mitigation may be needed because of different safety characteristics of this alternative refrigerant compared to HFC-134a.

156

Appendix A.9

Best Practice 1-9:

Alternative Refrigerants - HFC-152a

This best practice is assessed qualitatively. Table A-9 summarizes the assessment results in the standardized simplified reporting table format. Table A-9. Simplified Summary Table for Best Practice 1-9, Alternative Refrigerants HFC-152a Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information


Alternative Refrigerants - HFC-152a Truck Air Conditioning System Improvement 1, 2, 4, 5, 6, 11, 16, 18, 19 1, 2, 4, 6, 7 HFC Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions in 2025 would be 2.35%. N The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas HFC-152a has GWP = 120. Therefore, HFC-152a is being investigated as an alternative refrigerant. 2.35% N/A 91% The incremental capital cost of HFC-152a air conditioning system is from $22.5 per truck for additional safety equipment, including in-cabin leak sensors and engine compartment evacuation valves, to $50 per truck for secondary loop designs. This system uses alternative refrigerant with low GWP. The transition from HFC-134a to HFC-152a would be relatively easy (compared to a transition to CO2) since these two refrigerants have similar thermodynamic properties and A/C system components need less modification. The flammability of this alternative refrigerant, although moderate, motivates the need for additional safety assessment and potential risk mitigation

157

Appendix A.10

Best Practice 1-10:

Alternative Refrigerants - HC

This best practice is assessed qualitatively. Table A-10 summarizes the assessment results in the standardized simplified reporting table format. Table A-10. Attribute

Simplified Summary Table for Best Practice 1-10, Alternative Refrigerants - HC Description

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information


Alternative Refrigerants - HC Truck Air Conditioning System Improvement 1, 2, 4, 5, 6, 11, 16, 18, 19 1, 2, 4, 6, 7 HFC Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions in 2025 would be 2.46%. N The current widely used refrigerant, HFC-134a, has GWP = 1,300, whereas propane has GWP = 20. Therefore, propane is being investigated as an alternative refrigerant. 2.46% N/A 98.5% The incremental capital cost of HC air conditioning system is from $22.5 per truck for additional safety equipment, including in-cabin leak sensors and engine compartment evacuation valves, to $50 per truck for secondary loop designs. This system uses alternative refrigerant with low GWP. However, this system may use 10% more energy for the operation of vehicle air conditioners and increases indirect GHG emissions. The flammability of this alternative refrigerant, although moderate, motivates the need for additional safety assessment and potential risk mitigation. Release of propane to the atmosphere may also increase tropospheric ozone formation.

158

Appendix A.11

Best Practice 1-11: Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares


Simplified Summary Table for Best Practice 1-11, Vehicle Profile Improvement I Cab Top Deflector, Sloping Hood and Cab Side Flares Description


Vehicle Profile Improvement I - Cab Top Deflector, Sloping Hood and Cab Side Flares Truck Aerodynamic Drag Improvement 1, 2, 5, 6 1, 2, 6 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.43% and 1.47%, respectively. C These add-on devices can reduce truck tractor aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. 1.43% 1.47% N/A The incremental capital cost of this system is approximately $750 per truck. These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account.

159

Appendix A.12

Best Practice 1-12: Vehicle Profile Improvement II - Closing and Covering of Gap between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers


Simplified Summary Table for Best Practice 1-12, Vehicle Profile Improvement II - Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Description


Vehicle Profile Improvement II - Closing and Covering of Gap Between Tractor and Trailer, Aerodynamic Bumper, Underside Air Baffles, and Wheel Well Covers Truck Aerodynamic Drag Improvement 1, 2, 5, 6 1, 2, 6 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.37% and 2.44%, respectively. C These add-on devices can reduce truck side and underside aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. 2.37% 2.44% N/A The incremental capital cost of this system is approximately $1,500 per truck. These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. Although this best practice increases truck weight slightly, the estimated reduction in fuel use and GHG emissions takes this into account.

160

Appendix A.13

Best Practice 1-13: Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures

This best practice is assessed qualitatively. Table A-13 summarizes the assessment results in the standardized simplified reporting table format. Table A-13. Simplified Summary Table for Best Practice 1-13, Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks

Vehicle Profile Improvement III - Trailer or Van Leading and Trailing Edge Curvatures Truck Aerodynamic Drag Improvement 1, 2, 5, 6 1, 2, 6 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.24% and 1.28%, respectively. C These add-on devices can reduce truck trailer (or van) aerodynamic drag, increase their fuel efficiency and reduce GHG emissions. 1.24% 1.28% N/A The incremental capital cost of this system is approximately $500 per truck. These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions.

161

Appendix A.14

Best Practice 1-14:

Pneumatic Aerodynamic Drag Reduction


Simplified Summary Table for Best Practice 1-14, Pneumatic Aerodynamic Drag Reduction Description


Pneumatic Aerodynamic Drag Reduction Truck Aerodynamic Drag Improvement 1, 2, 4, 5, 6, 7, 16, 18, 19 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.17% and 2.24%, respectively. N This system blows air from slots at the rear of the trailers of heavy-duty vehicles to reduce aft-end aerodynamic drag and reduce energy use and GHG emissions. 2.17% 2.24% N/A The estimated incremental capital cost is $2,500, but could be as high as $5,250. This system that reduces aerodynamic drag can reduce energy use and GHG emissions. If used in combination with another best practice, such as Best Practice 1-12, there may be a negative synergistic effect in that the total improvement in aerodynamics is less than the linear sum of improvements from individual practices.

162

Appendix A.15

Best Practice 1-15:

Planar Boat Tail Plates on a Tractor-Trailer


Simplified Summary Table for Best Practice 1-15, Planar Boat Tail Plates on a Tractor-Trailer Description


Planar Boat Tail Plates on a Tractor-Tailer Truck Aerodynamic Drag Improvement 1, 2, 3, 4, 5, 6, 7, 12, 16, 18, 19 1, 2, 3, 4, 5, 6, 7 CO2 Technology

Goal is to have all combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.76% and 3.88%, respectively. N Planar boat tail plates are testing add-on devices that reduce aft-end aerodynamic drag. These devices are rectangular plates mounted to the after-end of a trailer that reduce the wake of trucks. 3.76% 3.55% N/A N/A These add-on devices that reduce aerodynamic drag can reduce energy use and GHG emissions. The drawback of this practice is that it may interfere with loading and unloading operations, depending on the design.

163

Appendix A.16

Best Practice 1-16:

Vehicle Load Profile Improvement


Simplified Summary Table for Best Practice 1-16, Vehicle Load Profile Improvement Description

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Vehicle Load Profile Improvement Truck Aerodynamic Drag Improvement 1, 2, 3, 5 1, 2, 3, 5, 6 CO2 Technology

Goal is to have all non-van trailers within combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.43% and 0.44%, respectively. C Aerodynamic drag can be reduced by the use of a streamlined load profile for a trailer. This practice keeps the load profile of a trailer as low as possible and secures tarpaulins to smooth air flow to reduce energy use and GHG emissions. 0.43% 0.44% N/A N/A This low-tech option that reduces aerodynamic drag can reduce energy use and GHG emissions. The drawback of this practice is that extra work for loading and unloading operations may be required.

164

Appendix A.17

Best Practice 1-17:

Automatic Tire Inflation Systems


Simplified Summary Table for Best Practice 1-17, Automatic Tire Inflation Systems Description



Automatic Tire Inflation Systems Truck Tire Rolling Resistance Improvement 1, 2, 4, 5, 6, 7, 8, 12 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.56% and 0.58%, respectively. C These systems can keep tires to the right pressure by monitoring and continually adjusting the level of pressurized air in tires. With properly vehicle tire inflation, tire rolling resistance is decreased and fuel use is reduced. 0.56% 0.58% N/A The estimated incremental capital cost is $900. The tire maintenance cost saving is about $200 annually. While these systems are installed, drivers do not need to check tire pressure manually and can pay less attention to their truck tires.

165

Appendix A.18

Best Practice 1-18: Wide-Base Tires


Simplified Summary Table for Best Practice 1-18, Wide-Base Tires Description



Wide-Base Tires Truck Tire Rolling Resistance Improvement 1, 2, 5, 6, 7 1, 2, 6 CO2 Technology

Goal is to have all combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.03% and 2.10%, respectively. C Dual tires that combination trucks usually have are heavy and also produce high rolling resistance. Single wide-base tires can replace these dual tires on combination trucks. Wide-base tires that have lower weight and produce lower rolling resistance reduce energy use. 2.03% 2.10% N/A The estimated incremental capital cost is $700 in average. New trucks with wide-base tires are possibly cheaper than with dual tires, but retrofitting existing trucks have higher cost. This practice has lower weight and produces lower rolling resistance. Aerodynamic drag and pass-by noise may also be decreased slightly. By using single instead of dual tires, there is a need for increased attention to tire inflation pressure for safety reasons

166

Appendix A.19

Best Practice 1-19:

Low-Rolling-Resistance Tires

This best practice is assessed qualitatively. Table A-19 summarizes the assessment results in the standardized simplified reporting table format. Table A-19. Simplified Summary Table for Best Practice 1-19, Low-Rolling-Resistance Tires Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary Potential Reductions in Modal GHG Emissions Potential Reduction in Modal Energy Use Potential Reduction in Modal HFC Use Cost Information Benefits and Drawbacks

Low-Rolling-Resistance Tires Truck Tire Rolling Resistance Improvement 1, 2, 5, 6, 7 1, 2, 6 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 2.83% and 2.91%, respectively. P Trucks with low-rolling resistance tires are fuel-efficient because of the reduction of tire rolling resistance. 2.83% 2.91% N/A The estimated incremental capital cost is $550. This practice produces lower rolling resistance. However, the requirements for higher inflation pressure and high monitoring frequency may limit the extent of their market penetration. The fuel saving advantage tends to be reduced when these low-resistance tires wear down.

167

Appendix A.20

Best Practice 1-20:

Pneumatic Blowing to Reducing Rolling Resistance


Simplified Summary Table for Best Practice 1-20, Pneumatic Blowing to Reducing Rolling Resistance Description



Pneumatic Blowing to Reducing Rolling Resistance Truck Tire Rolling Resistance Improvement 1, 2, 4, 5, 6, 7, 8, 12, 16, 18, 19 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all combination trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.54% and 0.56%, respectively. N This system for reducing aft-end aerodynamic drag blows air from slots at the rear of the trailers of heavy-duty vehicles. The installation of additional pipes, jets, valves, selective blowing, and control system can blow air under trucks. These air streams provide a slight lift that reduces tire rolling resistance. 0.54% 0.56% N/A If the pneumatic blowing system for reducing aerodynamic drag has been installed on a combination truck, additional $500 capital cost for extra components would be needed. This practice can utilize the air-blowing system to reduce rolling resistance and reduce tire wear. This practice may also assist conventional truck control and improve safety. However, this system may slightly increase dust pollution by dislodging particles on the road surface.

168

Appendix A.21

Best Practice 1-21: Hybrid Trucks


B.


Assumption:

The growth rate of medium-duty trucks is the same as the growth rate of total trucks for the truck mode from 2003 to 2025.

(a)

2003 Results:

It is estimated that there were 2,824,000 trucks as medium-duty trucks in 2003.18

(b) 2025 Results:

Since the growth rates of medium-duty trucks and total trucks are the same and the number of total trucks is estimated to grow by 67% from 2003 to 2025, which is explained in Appendix A.1.A, there will be 4,716,000 trucks as medium-duty trucks in 2025.

Estimate of annual transport activity for the mode: Annual transport activity for the mode is explained in Appendix A.1.

C.

Estimate of annual transport activity to which a practice is applicable: (a)

Assumption:

The ratio of annual transport activity of medium-duty trucks to annual transport activity of all trucks is proportional to the ratio of energy use for medium-duty trucks to energy sue for all trucks.

(b)

Calculation:

The ratio of energy use for medium-duty trucks to energy use for all trucks is estimated to be 17.8%.20

(c)

Results:

Since the ratio is 17.8%, the estimated total ton-miles for medium-duty trucks in the U.S. in 2025 will be 373 ×109 ton-miles.

169

Table A-21.

Standardized Reporting Table for Best Practice 1-21, Hybrid Trucksa

Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description Hybrid Trucks Truck Hybrid Propulsion 1, 2, 4, 5, 6, 8, 9, 12, 16, 18, 19, 20, 21, 22 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all local traveled medium-duty trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.4% (24.5 ×106 tons of CO2 eq.) and 3.5% (300 ×1012 Btu), respectively. N Hybrid propulsion systems recover or recycle energy for braking or deceleration to reduce truck fuel use. They help to shut off the engine under idling conditions within stop-and-go driving. Unit Value 109 ton-miles/year 2,098

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is 373 109 ton-miles/year Applicable (ATAP) Annual GHG Emissions Reductions(AGR) 106 ton CO2 eq./year 24.5 Annual Energy Use Reduction (AER) 1012 BTU /year 300 Annual Refrigerant Use Reduction (ARR) lbs/year N/A Unit GHG Emissions Reductions (UGER) 10-3 lb CO2 eq./ton-mile 130 Unit Energy Use Reduction (UER) BTU /ton-mile 804 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs Capital Cost I 106 USD ($) 9,210 Discount Rate I % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year-1 0.131 Annual O & M Cost (AOM) $106 /year 1,220 6 Annualized Cost (AC) $10 /year 2,430 Annual Energy Cost Saving (AECS) $106 /year 5,620 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A 6 Net Savings (NS) $10 /year 3,190 Net Savings per Unit of GHG Emissions Reductions 130 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 10.6 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 2.1 a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. 170

D.


Assumption:

i. Total GHG emissions reductions are due to energy use. ii. Approximately 47% of total travel distance for medium-duty trucks is within local area.49 iii. Hybrid medium-duty trucks traveled locally are estimated to increase fuel economy by 71%,49 which is equal to reduce energy use by 41.5%.

(b)

Calculation:

i. Adopting hybrid medium-duty trucks for local area purpose is estimated to reduce energy use for medium-duty trucks by 19.5%.

(41.5% × 47%) = 19.5% ii. Since the ratio of energy use for medium-duty trucks to energy use for all trucks is 17.8%, adopting hybrid medium-duty trucks for local area use is estimated to reduce energy use for the whole truck mode by 3.49%.

(19.5% × 17.8%)

= 3.49%.

iii. Total energy use reduction in 2003 is estimated to be 1.82×108 (106 BTU) per year.

(3.49% × 5.21×10

15

)

BTU = 1.82 × 1014 BTU.

iv. Since the truck mode is estimated to grow by 67% from 2003 to 2025,4 the estimated annual energy use reduction in 2025 is 3.0×108 (106 BTU). v. Total GHG emissions reductions due to fuel use reduction are estimated to be 24.5×106 tons CO2 eq. in 2025.

 0.0808 tons CO 2 eq.   3.0 × 1014 BTU ×  = 24.5 × 10 6 tons CO eq. 2 6   10 BTU  

171

(c)

E.

Results:

The annual GHG emissions reductions are estimated to be 24.5×106 tons CO2 eq. in 2025.

Estimate of annual energy use reduction: The estimated annual energy use reduction in 2025 is 300×1012 BTU, estimated in Appendix A.21.D.

F.

Estimate of unit GHG emissions reductions:  24.5 × 10 6 tons CO eq   2,000 lbs  0.13 lb CO eq. 2 2  . ×   =  373 × 10 9 ton − miles   ton ton − mile   

G.


(

)

 3.0 × 10 8 10 6 BTU  803.6 BTU  . = 9 ton − mile 373 × 10 ton − miles   H.

Estimate of capital cost i. The estimated incremental capital cost for a hybrid truck is $3,100 in 2025.49 ii. Approximately 63% of medium-duty trucks are used locally.49 iii. Total incremental capital costs of medium-duty hybrid trucks in 2025 are estimated to be $9.21×109. $3,100 × 4.72 × 10 6 trucks × 63% = $9.21 × 10 9 truck

I.

Estimate of annual O & M cost (a) Assumption: i. Battery cost is estimated to be 50% of incremental capital cost of a hybrid truck.49 ii. Lifetime of battery is estimated to be 5 years.

172

iii. Discount rate is 10%. (b)

Calculation:

i. Based on the estimated lifetime and discount rate, fixed charged factor is estimated to be 0.264. ii. Total annual cost for battery is estimated to be $1.22 ×109. $3,100 × 50% × 0.264 × 4.72 × 10 6 trucks × 63% = $1.22 × 10 9 truck

(c)

J.

Results:

The estimated annual O & M cost is estimated to be $1.22 ×109.

Estimate of annualized cost: (a) Assumption: i. The life-time of hybrid trucks is estimated to be 15 years. ii. Discount rate is 10%. (b)

Calculation:

i. Based on the estimated lifetime and discount rate, fixed charged factor is estimated to be 0.131. ii. ($9.21 × 10 9 × 0.131) + ($1.22 × 10 9 ) = $2.43 × 10 9

(c)

K.

Results:

The estimated annualized cost is estimated to be $2.43 ×109.


Calculation:


(

)

1.82 × 10 8 10 6 BTU ×

(c)

L.

Results:

$18.5 = $3.37 × 10 9 6 10 BTU

Since total energy use for the truck mode is estimated to grow by 67% from 2003 to 2025,4 the estimated energy cost reduction in 2025 is $5.62 ×109.

Estimate of net savings:

$5.62 × 109 − $2.43 × 109 = $3.19 × 109

173

M.

Estimate of net savings per unit of GHG emissions reductions: $3.19 ×10 9 24.5 ×10 tons CO 2 eq. 6

N.

$130.2 ton CO 2 eq.

=

Estimate of net savings per unit of energy use reduction: $3.19 ×10 9 $10.6 = 12 300 ×10 BTU 10 6 BTU

O.

Estimate of simple payback period: $9.21 × 10 9 = 2.1 years $5.62 × 10 9 − $1.22 × 10 9

(

)

174

Appendix A.22

Best Practice 1-22:



Simplified Summary Table for Best Practice 1-22, Lightweight Materials Description


Lightweight Materials Truck Weight Reduction 1, 2, 5, 6, 7, 10, 16, 18, 19 1, 2, 6 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 4.62% and 4.76%, respectively. P Using high-strength, light-weight components, including aluminum, plastics, and others, reduces the weight of trucks that can significantly reduce fuel use and reduce GHG emissions. 4.62% 4.76% N/A The estimated incremental capital cost is $2,000. Lightweight components can reduce truck fuel use, allow more cargo and increase productivity. However, current light-weight materials are costly and with no satisfied material characteristics. However, current light-weight materials are costly and with no satisfied material characteristics. Further research and development for advanced materials are needed.

175

Appendix A.23

Best Practice 1-23:

Advanced Transmission


Simplified Summary Table for Best Practice 1-23, Advanced Transmission Description



Advanced Transmission Truck Transmission Improvement 1, 2, 4, 5, 6, 9, 16, 18, 19 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.97% and 1.00%, respectively. P A continuously variable transmission (CVT) has belt-connected pulleys that can optimize speed-load conditions and reduce fuel use. Mechanical losses in a transmission can be reduced by the reduction of gear surface roughness, the use of low-friction coatings, the use of new gear materials, and the use of the lock-up torque converter. 0.97% 1.00% N/A The estimated incremental capital cost is $1,000. CVTs have smoother operation and allow the engine speed to remain at the level of peak efficiency to reduce energy use and emissions. Driver training may be needed to avoid the confusion because the sound of the engine with traditional transmissions changes for acceleration operations but the sound of the engine with improved transmission does not change in the condition of acceleration.

176

Appendix A.24

Best Practice 1-24: Transmission Friction Reduction through Low-Viscosity Transmission Lubricants


Simplified Summary Table for Best Practice 1-24, Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Description


Transmission Friction Reduction through Low-Viscosity Transmission Lubricants Truck Transmission Improvement 1, 2, 4, 5, 9, 15 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.92% and 0.95%, respectively. C Low-viscosity transmission fluids can be adopted to decrease transmission friction and also reduce fuel consumption. 0.92% 0.95% N/A The estimated incremental capital cost is $500. Low-viscosity lubricants can reduce energy use, but it typically costs more than conventional lubricants.

177

Appendix A.25

Best Practice 1-25: Engine Lubricants

Engine Friction Reduction through Low-Viscosity


Simplified Summary Table for Best Practice 1-25, Engine Friction Reduction through Low-Viscosity Engine Lubricants Description


Engine Friction Reduction through Low-Viscosity Engine Lubricants Truck Diesel Engine Improvement 1, 2, 4, 5, 9, 15 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.81% and 1.86%, respectively. C Low-viscosity engine lubricants are made from synthetic or mineral oil blends for the purpose of reducing internal engine friction. 1.81% 1.86% N/A The estimated incremental capital cost is $500. Low-viscosity lubricants can reduce energy use, but it typically costs more than conventional lubricants.

178

Appendix A.26

Best Practice 1-26:

Increased Peak Cylinder Pressures


Simplified Summary Table for Best Practice 1-26, Increased Peak Cylinder Pressures Description



Increased Peak Cylinder Pressures Truck Diesel Engine Improvement 1, 2, 4, 5, 6, 9 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all heavy-duty trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.07% and 3.16%, respectively. C Diesel engine thermal efficiency is proportion to the peak pressures that can be achieved in the engine cylinders. However, the peak cylinder pressures are constrained by the strength and durability of the engine materials over the design service life of the engine. Measures that result in better materials that enable higher peak pressures can lead to higher engine efficiency. 3.07% 3.16% N/A The estimated incremental capital cost is $1,000. They can withstand higher peak cylinder pressures and increase thermal efficiency.

179

Appendix A.27

Best Practice 1-27:

Improved Fuel Injectors


Simplified Summary Table for Best Practice 1-27, Improved Fuel Injectors Description



Improved Fuel Injectors Truck Diesel Engine Improvement 1, 2, 4, 5, 6, 9 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.49% and 5.66%, respectively. P Incorrect fuel injection causes a reduction of combustion efficiency and an increase of emissions. The improvement of fuel injection via better control is expected to reduce truck fuel use. For example, advanced fuel injection systems, such as electronic unit injectors or common rail injectors with increased fuel injection pressure, are estimate to result in better control of the fuel injection rate and injection timing, and to produce finer vaporization of the fuel spray. 5.49% 5.66% N/A The estimated incremental capital cost is $1,500. These systems have better control of the fuel injection rate, injection timing, and finer fuel spray. However, a drawback of higher injection pressures is the need to have stronger fuel-injection system and other engine components that withstand the higher pressures. The improved high pressure injectors may have leakage problem after a period of operation time. Regular diagnosis is needed to identify and address this problem.

180

Appendix A.28

Best Practice 1-28: Turbocharged, Direct Injection to Improved Thermal Management


Simplified Summary Table for Best Practice 1-28, Turbocharged, Direct Injection to Improved Thermal Management Description



Turbocharged, Direct Injection to Improved Thermal Management Truck Diesel Engine Improvement 1, 2, 4, 5, 6, 9 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all medium-duty trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.82% and 0.85%, respectively. C Turbocharger is a turbine that is driven by the exhaust air flow form the engine and increase air intake. Advanced turbochargers that drive more air into the cylinder increase combustion efficiency and allow direct injectors to inject more fuel into cylinders. 0.82% 0.85% N/A The estimated incremental capital cost is $700-1,000. The combination of turbocharger and direct injector allow for precise control of the fuel/air mixture which produce more power and higher fuel efficiency.

181

Appendix A.29

Best Practice 1-29: Heat

Thermoelectric Technology to Recovery Waste


Simplified Summary Table for Best Practice 1-29, Thermoelectric Technology to Recovery Waste Heat Description



Thermoelectric Technology to Recovery Waste Heat Truck Diesel Engine Improvement 1, 2, 4, 5, 6, 9 1, 2, 4, 6, 7 CO2 Technology

Goal is to have all heavy-duty trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.22% and 5.38%, respectively. N Overall engine thermal efficiency can be increased if new materials and technologies can be developed and implement for improved thermal management. An example is the conversion of engine waste heat to electrical energy. Such systems are not commercially available and are undergoing development. Combining thermoelectric materials and advanced heat exchangers may recover waste heat in order to produce electricity. 5.22% 5.38% N/A The estimated incremental capital cost is $2,000. Thermoelectric converter technology needs further research and development (R & D) to increase its currently low conversion efficiency. The estimates reported here presume that such R & D will be successful.

182

Appendix A.30

Best Practice 1-30:

Electric Auxiliaries

This best practice is assessed qualitatively. Table A-30 summarizes the assessment results in the standardized simplified reporting table format. Table A-30. Simplified Summary Table for Best Practice 1-30, Electric Auxiliaries Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Electric Auxiliaries Truck Accessory Load Reduction 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12 1, 2, 3, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.43% and 1.48%, respectively. C Most mechanical auxiliaries operate whenever truck base engines are running, which waste energy when the auxiliaries are not needed. The replacement of gear- or belt-driven auxiliaries by electrically driven systems can decouple mechanical loads from the base engine and reduce energy use. An electric truck can use a generator to produce electricity as power source for electric auxiliaries. 1.43% 1.48% N/A The estimated incremental capital cost is $500. More electric trucks can reduce fuel use rate and reduce GHG emissions. The smaller generator for this practice may need pollution control devices in order to comply with future emissions standards.

183

Appendix A.31

Best Practice 1-31:

Fuel-Cell-Operated Auxiliaries

This best practice is assessed qualitatively. Table A-31 summarizes the assessment results in the standardized simplified reporting table format. Table A-31. Simplified Summary Table for Best Practice 1-31, Fuel-Cell-Operated Auxiliaries Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Fuel-Cell-Operated Auxiliaries Truck Accessory Load Reduction 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12 1, 2, 3, 4, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.49% and 5.66%, respectively. N Fuel cells are an emerging technology for converting chemical energy in a fuel directly to electricity. The advantage of fuel cells over conventional engine and alternator technology is that they have substantially higher thermal efficiency. Among the barriers to practical use of fuel cells are the cost of precious materials used for their internal components and the need for conversion of readily available transportation fuels to a form that can be processed by the fuel cell. The use of fuel cells coupled with electrically operated auxiliaries could be available in the market by 2012. 5.49% 5.66% N/A The estimated incremental capital cost is $1,500. This practice has high thermal efficiency, but further R & D is needed in order to reduce cost.

184

Appendix A.32

Best Practice 1-32:

Truck Driver Training Program

This best practice is assessed qualitatively. Table A-32 summarizes the assessment results in the standardized simplified reporting table format. Table A-32. Simplified Summary Table for Best Practice 1-32, Truck Driver Training Program Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Truck Driver Training Program Truck Modifications in Driver Operational Practice 1, 2, 5 1, 2, 5, 6 CO2 Operation

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would be 3.10% and 3.19%, respectively. C The behavior of truck drivers can significantly impact fuel efficiency. Drivers can be encouraged to modify behaviors that unnecessarily increase fuel use via training programs that aim to convey better skills and habits. Furthermore, driver performance can be monitored and incentives can be provided to reward preferred behaviors. 3.10% 3.19% N/A N/A Driver training can reduce fuel consumption significantly.

185

Appendix A.33

Best Practice 1-33:

B20 Biodiesel Fuel for Trucks



2003 Results:

(b) 2025 Results:

B.

It is estimated that there were 7.9 million trucks in 2003.3 Since total truck number is estimated to grow by 67% from 2003 to 2025, which is explained in Appendix A.1.A, there will be 13.2 million trucks in 2025.


C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is the same as the transport activity for the whole mode, which is explained in Appendix A.1.B.

D.


Assumption:

i. The net life-cycle CO2 emissions reduction of B20 biodiesel is about 0.0069 tons CO2 eq. per 106 BTU, which is estimated in Appendix F.2.3.61 ii. Biodiesel industry was estimated that it has the potential to produce 1.7 billion gallons of B100 biodiesel in 2003, 3.5 billion gallons of B100 biodiesel in 2015, and 10 billion gallons of B100 biodiesel in 2030.63,64 Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons.

186

Table A-33. Standardized Reporting Table for Best Practice 1-33, B20 Biodiesel Fuel for Trucksa Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description B20 Biodiesel Fuel for Trucks Truck Alternative Fuels 1, 2, 4, 5, 6, 12, 14, 16, 18, 19, 20, 21, 22 1, 2, 4, 5, 6, 7 CO2 Technology

Goal is to have all trucks participate. The reductions in modal GHG emissions and energy use in 2025 would 4.27% (30.8 ×106 tons of CO2 eq.) and -4.25% (-370 ×1012 Btu), respectively. C The life-cycle CO2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO2 eq. per 106 BTU compared to that of petroleum diesel. Unit Value 109 ton-miles/year 2,098

Practice Goals Developmental Status Practice Summary

Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is 2,098 109 ton-miles/year Applicable (ATAP) 6 Annual GHG Emissions Reductions(AGR) 10 ton CO2 eq./year 30.8 Annual Energy Use Reduction (AER) 1012 BTU /year -370 Annual Refrigerant Use Reduction (ARR) lbs/year N/A -3 Unit GHG Emissions Reductions (UGER) 10 lb CO2 eq./ton-mile 29 Unit Energy Use Reduction (UER) BTU /ton-mile -176 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs Capital Cost I 106 USD ($) N/A Discount Rate I % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year-1 N/A Annual O & M Cost (AOM) $106 /year N/A Annualized Cost (AC) $106 /year 3,340 Annual Energy Cost Saving (AECS) $106 /year 0 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year -3,340 Net Savings per Unit of GHG Emissions Reductions -108 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU N/Ab Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years N/Ac a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. b This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. 187

c

There is no pay-back period for this best practice because there is no net saving.

iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heating value of petroleum diesel is 138,690 BTU/gallon.131-132 Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon. iv. The truck mode consumed 4.6×1015 BTU of diesel fuel in 2003.2,3 The rail mode consumed 0.531×1015 BTU diesel in 2003.3 The water mode consumed 0.385×1015 BTU distillate fuel oil in 2003.1,3 v. The potential market share of B20 biodiesel for the truck mode is estimated to be 51.2% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes. (b)

Calculation:

i. Energy use for the truck mode in 2025 is estimated to be 8.7×1015 BTU. ii. Maximum B20 biodiesel production capacity for the truck mode in 2003 is estimated to be 0.97×1015 BTU. iii. Maximum B20 biodiesel production capacity for the truck mode in 2025 is estimated to be 4.45×1015 BTU. 8.7 × 10 15 BTU × 51.2% = 4.45 × 10 15 BTU

iii. The annual GHG emissions reductions are estimated to be 30.8×106 tons CO2 eq. in 2025.

4.45 × 10 15 BTU × (c)

Results:

0.0069 CO 2 eq. 6

10 BTU

= 30.8 × 10 6 tons CO 2 eq.


188

E.

Estimate of annual energy use reduction: i.. Energy use reduction based on life cycle inventory is estimated to be -8.3%.61 ii. Energy use reduction based on life cycle inventory in 2025 is estimated to be -3.7×1014 BTU − 8.3%. × 4.45 × 1015 BTU = −3.7 × 1014 BTU

F.

Estimate of unit GHG emissions reductions:  30.8 × 10 6 tons CO eq   2,000 lbs  0.029 lb CO eq. 2 2 . ×   =  2097 × 10 9 ton − miles   ton  ton − mile  

G.


(

)

 − 3.7 × 10 8 10 6 BTU  − 176.4 BTU  . = 9 ton − mile  2097 × 10 ton − miles 

H.

Estimate of capital cost (Not available)

I.


J.

Estimate of annualized cost: i. The average fuel cost of B100 Biodiesel in April 2005 is estimated to be $22.2 per 106 BTU.137 ii. Diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $18.5/106 BTU.114 iii. Thus, B20 biodiesel fuel price is estimated to be $19.21/106 BTU, which is $0.75/106 BTU higher than the price of diesel fuel. iv. Annualized cost is estimated to be $3.34 ×109.

189

$0.75 × 4.45 × 1015 BTU = $3.34 × 10 9 6 10 BTU

K.

Estimate of energy cost reduction: (No energy cost reduction)

L.


$0 − $3.34 × 109 = −$3.34 × 109

M.

Estimate of net savings per unit of GHG emissions reductions: − $3.34 ×10 9 30.8 ×10 tons CO 2 eq. 6

=

− $108.4 ton CO 2 eq.

N.

Estimate of net savings per unit of energy use reduction: (Not available: This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving).

O.

Estimate of simple payback period: (Not available: there is no pay-back period for this practice because there is no net saving).

190

APPENDIX B.

DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR RAIL MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 5, including the standardized reporting tables, if their corresponding best practices can be assessed quantitatively, or the simplified summary tables, if their corresponding best practices are assessed qualitatively. For those assessed quantitatively, the methods for the estimation of data in the standardized reporting tables are also described. Appendix B.1

Best Practice 2-1: Combined Diesel Powered Heating System and Auto Engine Start/Stop System

This best practice is assessed quantitatively. Table B-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained. A.


Assumption:

Annual per-locomotive energy use in 2025 is the same as annual per-locomotive energy use in 2003.

(b) Calculation:

i. It is estimated that there were 20,774 Class I locomotives in 2003.3 ii. Since per-locomotive energy use is the same and modal energy use is estimated to grow by 49% from 2003 to 2025,4 locomotive number increases by 49% from 2003 to 2025. 20,774 × (1 + 49%) = 30,965

(c)

B.

Results:

There will be 30,965 Class I locomotives in 2025.


Assumption:

(b) 2003 Results:

The growth rate of total transport activity is the same as the growth rate of energy use for the rail mode. It is estimated that there were 1,551 ×109 ton-miles in 2003.3

191

Table B-1. Standardized Reporting Table for Best Practice 2-1, Combined Diesel Powered Heating System and Auto Engine Start/Stop Systema Characteristics of the Practice

Description Combined Diesel Powered Heating System and Auto Engine Start/Stop System Rail Anti-idling

Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

26, 27, 28, 35, 36, 37 11, 13 CO2 Technology

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) 192

Goal is to have all long-haul and switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would both be 3.62% (2.32 ×106 tons of CO2 eq. and 28.7 ×1012 Btu, respectively). P Diesel powered heating systems keep the engine block temperature above 100 oF. Such systems utilize waste heat from a small diesel engine to heat the main engine and to generate electricity using by an alternator. An auto engine start/stop system can shutdown and restart both long-haul and switching locomotive engines automatically, based on a preprogrammed set of values. Both of these systems can be used simultaneously to shut down the engine when not needed while also keep the engine warm in preparation for a restart and while maintaining batteries in a ready status. Unit Value 109 ton-miles/year 2,312 109 ton-miles/year

2,312


2.32 28.7 N/A 2.0 12.4 N/A

106 USD ($) % years year-1

1,100 10% 15 0.131

a

Annual O & M Cost (AOM) $106 /year N/A Annualized Cost (AC) $106 /year 144.0 Annual Energy Cost Saving (AECS) $106 /year 531.4 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year 387.4 Net Savings per Unit of GHG Emissions Reductions 167 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 13.5 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 2.1 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

(c)

C.

2025 Results:

Since total energy use for the rail mode is estimated to grow by 49% from 2003 to 2025,4 there will be 2,312 ×109 ton-miles in 2025.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is the same as the total ton-miles of this mode, which is explained in Appendix B.1.B.

D.

Estimate of annual GHG emissions reductions: Assumption: (a)

i. Total GHG emissions reductions are due to energy use reduction. ii. Long-haul Class I locomotives work 330 days per year and 55% of time is at idle.67 Switchers work 330 days per year72 and 75% of time of switchers is at idle.67 55% of idle time is used for all locomotive for the estimation in order to simplify the calculation. iii. Idle fuel use for a Class I locomotive is estimated to be 3 gallon per hour.138 iv. This best practice is applicable to both long-haul locomotives and switchers. ix. This practice can reduce idle time by 64% if 55% of time is at idle,68 and reduce fuel use at idle by 80%.67 193

(b)

Calculation:

i. Class I locomotives consume fuel at idle in 2025 is estimated to be 5.61×1013 BTU.

138690 BTU   3 gallon  30965 ×  × × × × 24 hrs 330 days 55 %   gallon hr   13 = 5.61 × 10 BTU ii. Energy use reduction for adopting this practice in 2025 is estimated to be 2.87×1013 BTU. 5.61 × 1013 BTU × 64% × 80% = 2.87 × 1013 BTU

iii. Total GHG emissions reductions in 2025 due to fuel use reduction are estimated to be 2.32×106 tons CO2 eq.  0.0808 tons CO 2 eq.   2.87 × 1013 BTU ×  = 2.32 × 10 6 tons CO eq. 2 6   10 BTU  

(c)

E.

Results:


Estimate of annual energy use reduction: The estimated annual energy use reduction in 2025 is 2.87×107 (106 BTU), which is estimated in Appendix B.1.D.

F.

Estimate of unit GHG emissions reductions:  2.32 × 10 6 tons CO 2 eq   2,000 lbs  0.002 lb CO 2 eq.      2312 × 10 9 ton − miles . ×  ton  = ton − mile    

G.


(

)

 2.87 × 10 7 10 6 BTU  12.4 BTU . =  9 2312 10 ton miles × −  ton − mile 

194

H.

Estimate of capital cost The estimated capital cost for this practice is $35,500 per locomotive.68 costs for all locomotives in 2025 is estimated to be $1.1 ×109.

Total capital

$35,500 × 30,965 locomotives = $1.1 × 10 9 = $1.1 × 10 9 truck

I.


J.

Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years. ii. Fixed charge factor is estimated to be 0.131. Fixed ch arg e factor (a ) =

1  15  1 ∑  i =1  (1 + 0.1)i  

   

= 0.131

iii. Annualized cost is estimated to be $144.0 ×106.

($1.12 × 10 K.

9

)

× 0.131 = $144.0 × 10 6


Calculation:


(

)

2.87 × 10 7 10 6 BTU × ×

(c) L.

Results:

$18.5 = $531.4 × 10 6 6 10 BTU



$531.4 × 10 6 − $144.0 × 10 6 = $387.4 × 10 6

M.

Estimate of net savings per unit of GHG emissions reductions: 195

$0.387 ×10 9 2.32 ×10 tons CO 2 eq. 6

N.

=

$167.0 ton CO 2 eq.

Estimate of net savings per unit of energy use reduction: $0.387 ×10 9 $13.5 = 12 28.7 ×10 BTU 10 6 BTU

O.

Estimate of simple payback period: $1.1 × 10 9 = 2.1 years $0.531 × 10 9

(

)

196

Appendix B.2

Best Practice 2-2:

Battery-Diesel Hybrid Switching Locomotive



Assumptions:

i. Assuming that the national ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), the largest railroad company in the U.S., approximately 71% of locomotives are long-haul.125 ii. The remainder (29% of locomotives) are switchers. iii. The growth rate of total switcher number is the same as the growth rate of total locomotive number for the rail mode.

(b) Calculations:

i. It is estimated that 2003.3

there were 20,774 Class I locomotives in

ii. It is estimated that there were 6,000 switching locomotives in 2003.

(20,774 × 29%) (c)

B.

Results

= 6,000

Since total locomotive number for this mode is estimated to grow by 49% from 2003 to 2025, which is explained in Appendix B.1.A, there will be 8,860 switchers in 2025.

Estimate of annual transport activity for the mode: Annual transport activity for the rail mode is explained in Appendix B.1.B.

C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is the same as the total ton-miles of this mode, which is explained in Appendix B.1.C.

197

Table B-2. Standardized Reporting Table for Best Practice 2-2, Battery-Diesel Hybrid Switching Locomotive a Characteristics of the Practice

Description Battery-Diesel Hybrid Switching Locomotive Rail Anti-Idling


26, 27 11 CO2 Technology


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs 198

Goal is to have all switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would both be 1.75% (1.12 ×106 tons of CO2 eq. and 13.8 ×1012 Btu, respectively). C Battery-diesel hybrid switchers are commercially available locomotives that can replace traditional switching locomotives. Traditional switchers typically have 2,000 hp diesel engines. Battery-diesel hybrid switchers include a small diesel engine (e.g., 125 to 300 hp) and large (60,000 lbs) lead-acid batteries. This small diesel engine is used to charge batteries that maintain batteries in a ready status during periods of locomotive non-use. At full load, the batteries account for 95% of the horsepower and the small diesel engine accounts for another 5%. This hybrid switcher also has an auto start/stop system that contains a microprocessor to automatically shut down the small diesel engine during periods of locomotive non-use or when the batteries are fully charged based on battery voltage values. Unit Value 109 ton-miles/year 2,312 109 ton-miles/year 6


2,312 1.12 13.8 N/A 1.0 6.0 N/A

a

Capital Cost (C) 106 USD ($) 1401.4 Discount Rate (r) % 10% Technical Lifetime of Technology (L) years 15 Fixed Charge Factor (a) year-1 0.131 Annual O & M Cost (AOM) $106 /year N/A 6 Annualized Cost (AC) $10 /year 183.6 Annual Energy Cost Saving (AECS) $106 /year 255.8 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year 72.2 Net Savings per Unit of GHG Emissions Reductions 64.5 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 5.2 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 5.5 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

D.

Estimate of annual GHG emissions reductions: Assumption: (a)

i. Total GHG emissions reductions are due to energy use reduction. ii. Switchers work 330 days per year72 and 75% of time of switchers is at idle.67 iii. Assuming that the national ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), the largest railroad company in the U.S., approximately 71% of locomotives are long-haul.125 The remainder are switchers. iv. This practice is applicable to switchers only. v. Assuming that the national ratio of yard switchers to total locomotives is the same as the ratio for Union Pacific (UP), it is estimated that switchers account for only 5% of total locomotive fuel use.117 vi. Total fuel use for this mode in 2003 is 3.826 × 109 gallons.3 vii. This practice can reduce energy use for switchers by 35%.71 viii. Total GHG emissions for the rail mode is estimated to grow by 49% from 2003 to 2025, which is explained in Section 1.2.

(b)

Calculation:

i. Energy use for switchers in 2025 is estimated to be 3.95×1013 199

BTU.

138690 BTU    3.826 × 109 × × 5% × (1 + 49%) = 3.95 × 1013 BTU  gallon   ii. Energy use reduction in 2025 for adopting this practice is estimated to be 1.38×1013 BTU.

3.95 × 1013 BTU × 35% = 1.38 × 1013 BTU iii. Total GHG emissions reductions due to energy use reduction are estimated to be 1.12×106 tons CO2 eq. in 2025.  0.0808 tons CO 2 eq.  1.38 × 1013 BTU ×  = 1.12 × 10 6 tons CO eq. 2 6   10 BTU  

(c)

E.

Results:


Estimate of annual energy use reduction: The estimated annual energy use reduction in 2025 is 1.38×107 (106 BTU) while it is estimated in Appendix B.2.D.

F.

Estimate of unit GHG emissions reductions:  1.12 × 10 6 tons CO 2 eq   2,000 lbs  0.001 lb CO 2 eq.  . ×   =  2312 × 10 9 ton − miles   ton ton − mile    

G.


(

)

 1.38 × 10 7 10 6 BTU  6.0 BTU   = 9  2312 × 10 ton − miles  ton − mile

H.

Estimate of capital cost 200

(a)

Assumptions:

i. A switcher consumes 348 gallons of fuel per day.72 ii. A switcher works 330 days per day.72 iii. The working loads of switchers are 50%. 72 iv. Only a fraction of switchers are in use. v. The capital cost of a battery-diesel hybrid switcher is estimated to be $283,000.71

(b) Calculations:

i. Energy use for switchers in 2025 is estimated to be 3.95×1013 BTU, which is estimated in Appendix B.2.D. ii. It is estimated that there were 4,950 switching locomotives in use in 2025.

(3.95 × 10

13

BTU

)

138690 BTU     348 gallons × 330 days × 50% ×   gallon  

= 4,950

iii. For this estimation, 4,950 is the number of switchers used for estimating total capital cost because the switchers that are considered to be replaced by hybrid switchers are the switchers in use, not total switchers (total switchers are estimated to be 8,860, which is estimated in Appendix B.2.A.). iv. Total capital cost in 2025 is estimated to be $1.401 × 109.

4,950 × $283,000 = $1.401× 109 (c)

Results

Total capital cost in 2025 is estimated to be $1.401 × 109.

I.


J.

Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years. ii. Fixed charge factor is estimated to be 0.131.

201

Fixed ch arg e factor (a ) =

1  15  1 ∑  i =1  (1 + 0.1)i  

   

= 0.131

iii. Annualized cost is estimated to be $183.6 × 106.

($1.40 × 10 K.

9

)

× 0.131 = $183.6 × 10 6


Calculation:


(

)

1.38 × 10 7 10 6 BTU × ×

(c) L.

Results:

$18.5 = $255.8 × 10 6 6 10 BTU



$255.8 × 106 − $183.6 × 106 = $72.2 × 10 6

M.

Estimate of net savings per unit of GHG emissions reductions:

$72.2 ×10 6 1.12 ×10 6 tons CO 2 eq.

N.

=

$64.5 ton CO 2 eq.

Estimate of net savings per unit of energy use reduction: $72.2 ×10 6 $5.2 = 12 6 13.8 ×10 BTU 10 BTU

O.

Estimate of simple payback period: $1.40 × 10 9 = 5.5 years $255.8 × 10 6

(

)

202

Appendix B.3

Best Practice 2-3:

Plug-in Unit


Estimate of total number of vehicles or devices: Total number of switchers is explained in Appendix B.2.A.

B.

Estimate of annual transport activity for the mode: Annual transport activity for the mode is explained in Appendix B.1.B.

C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is explained in Appendix B.1.C.

D.


Assumption:

i. Total GHG emissions reductions are that GHG emissions reductions due to energy use reduction minus GHG emissions due to electricity use for operating this practice. iii. Switchers work 330 days per year72 and 75% of time of switchers is at idle.67 iv. Plug-in units consume 30 kW of electricity.134 vi. It is estimated that there will be 4,950 switching locomotives in use in 2025, which is estimated in Appendix B.2.H. iii. GHG emissions coefficient for diesel fuel is 0.0808 tons CO2 eq. per 106 BTU.1 vi. GHG emissions coefficient for electricity is 0.0007 tons CO2 eq. per kWh.108

203

Table B-3. Standardized Reporting Table for Best Practice 2-3, Plug-In Unit a Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description Plug-In Unit Rail Anti-Idling 26, 27 11 CO2 Technology

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) Annual O & M Cost (AOM) Annualized Cost (AC) Annual Energy Cost Saving (AECS) Annual Refrigerant Cost Saving (ARCS) Net Savings (NS) Net Savings per Unit of GHG Emissions Reductions 204

Goal is to have all switching locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.58% (0.37 ×106 tons of CO2 eq.) and 0.44% (3.5 ×1012 Btu), respectively. C Plug-in units are commercially available systems that can avoid the need for idling of switcher engines while switchers are parked in switching yards. These systems, which require both on-board and off-board components, enable locomotive drivers to switch off their diesel engines by plugging a locomotive into an external electrical power source. These systems can use electricity powered systems to supply heat, circulate and heat coolant and oil, and keep batteries charged. Unit Value 109 ton-miles/year 2,312 109 ton-miles/year 6

2,312

10 ton CO2 eq./year 1012 BTU /year lbs/year -3 10 lb CO2 eq./ton-mile BTU /ton-mile lbs/ton-mile

0.37 3.5 N/A 0.3 1.5 N/A

106 USD ($) % years year-1 $106 /year $106 /year $106 /year $106 /year $106 /year $/ton CO2 eq.

118.8 10% 15 0.131 75.6 91.2 225.7 N/A 134.6 363.6

a

(NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 38.4 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 0.79 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

(b)

Calculation:

i. Energy use for switchers in 2025 is estimated to be 3.95×1013 BTU, which is estimated in Appendix B.2.D. ii. Diesel fuel use reduction in 2025 for adopting this practice, which reduce idle time (75% of time), is estimated to be 1.22×1013 BTU.

3 gallons 138,690 BTU × × 330 days × 24 hrs × 75% × 4,950 hr gallon = 1.22 × 1013 BTU iii. GHG emissions reductions due to diesel fuel use reduction are estimated to be 0.986×106 tons CO2 eq. in 2025.  0.0808 tons CO 2 eq.  12.2 × 1012 BTU ×  6   10 BTU   = 0.986 × 10 6 tons CO 2 eq.

iv. Electricity needed for plug-in units for switchers at idle is estimated to be 8.82×108 kWh.

30 kW × 330 days × 24 hrs × 75% × 4,950 = 8.82 × 108 kWh v. GHG emissions due to electricity use for this practice are estimated to be 0.617 ×106 tons CO2 eq. in 2025.

205

 0.0007 tons CO 2 eq.   8.82 × 10 8 kWh ×    kWh   = 0.617 × 10 6 tons CO 2 eq.

v. Total GHG emissions reductions are estimated to be 0.37×106 tons CO2 eq. in 2025.

(0.986 − 0.617 ) × 10 6 (c)

E.

Results:

tons CO 2 eq. = 0.369 × 10 6 tons CO 2 eq.


Estimate of annual energy use reduction: (a)

Assumption:

i. Total energy use reduction is that energy use reduction minuses energy for producing electricity for operating this practice. ii. 1 kWh is equal to 3,412 BTU. iii. The ratio of primary energy input to electricity output is estimated to be 2.89 based on total electricity generated and total primary energy consumed in the U.S. in 2005.133

(b)

Calculation:

i. Diesel fuel use reduction in 2025 for adopting this practice is estimated to be 1.22×1013 BTU, which is estimated in Appendix B.3.D. ii. Electricity needed for plug-in units for switchers at idle in 2025 is estimated to be 8.82×108 kWh, which is equal to 3.01×1012 BTU.

30 kW × 330 days × 24 hrs × 75% × 4,950 = 8.82 × 108 kWh

8.82 × 108 kWh × 3,412 BTU = 3.01× 1012 BTU iii. Primary energy needed for producing electricity in order to operate this practice is estimated to be 8.70×1012 BTU.

206

3.01× 1012 BTU × 2.89 = 8.70 × 1012 BTU iv. The estimated annual energy use reduction in 2025 is 3.50×106 (106 BTU).

(

)

12.2 × 1012 BTU − 8.70 × 1012 BTU = 3.50 × 106 106 BTU (c)

F.

Results:

The estimated annual energy use reduction in 2025 is 3.50×106 (106 BTU), which is 8.86% of total energy use for switchers, or 0.44% of total energy use for the rail mode.

Estimate of unit GHG emissions reductions:  0.37 × 10 6 tons CO 2 eq   2,000 lbs  0.0003 lb CO 2 eq.     =  2312 × 10 9 ton − miles . ×  ton ton − mile    

G.


(

)

 3.50 × 10 6 10 6 BTU  1.51 BTU   = 9  2312 × 10 ton − miles  ton − mile

H.

Estimate of capital cost (a) Assumptions: i. There were 4,950 switching locomotives in use in 2025, which is estimated in Appendix B.2.H. ii. The capital cost of an on-board plug-in unit is estimated to be approximately $8,000.72 iii. The capital cost for truck stop electrification infrastructure per parking space is estimated to be from $6,000 to $16,000.139 iv. Assuming infrastructure cost for parking space for this practice is the same as the upper bound of the cost for truck stop electrification, total capital cost is estimated to be $24,000 per switcher.

207

(b) Calculations:

i. Total capital cost in 2025 is estimated to be $118.8 × 106.

4,950 × $14,000 = $118.8 × 10 6 (c) I.

Total capital cost in 2025 is estimated to be $118.8 × 106.

Results

Estimate of annual O & M cost (a) Assumption: Electricity price for transportation in 2025 is the same as the price for transportation in 2005, which is $0.0857/kWh.140 (b)

Calculation:

The estimated annual electricity cost in 2025 is $75.59 × 106.

$0.0857 = $75.59 × 10 6 kWh

8.82 × 10 8 kWh × × (c)

J.

The estimated annual electricity cost in 2025 is $75.59 × 106.

Results:


1  15  1 ∑  i =1  (1 + 0.1)i  

   

= 0.131

iii. Annualized cost is estimated to be $91.15 × 106.

($118.8 × 10 K.

6

)

× 0.131 + 75.59 × 10 6 = $91.15 × 10 6


Calculation:


(

)

12.2 × 10 6 10 6 BTU × ×

208

$18.5 = $225.7 × 10 6 6 10 BTU

(c) L.

Results:



$225.7 × 106 − $91.15 × 106 = $134.55 × 106

M.


$134.55 × 10 6 0.37 × 10 6 tons CO 2 eq.

N.

=

$363.6 ton CO 2 eq.

Estimate of net savings per unit of energy use reduction: $134.55 × 10 6 $38.4 = 12 3.5 × 10 BTU 10 6 BTU

O.

Estimate of simple payback period: $118.8 × 10 6 = 0.79 years $225.7 × 10 6 − $75.6 × 10 6

(

)

209

Appendix B.4

Best Practice 2-4:

Light Weight Materials

This best practice is assessed qualitatively. Table B-4 summarizes the assessment results in the standardized simplified reporting table format. Table B-4. Simplified Summary Table for Best Practice 2-4, Light Weight Materials Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Light Weight Materials Rail Weight Reduction 26, 27 11, 12 CO2 Technology

Goal is to have all Class I locomotives and railcars participate. The reductions in modal GHG emissions and energy use in 2025 would be both 4.76%. C The use of lighter-weight components to reduce the weight of locomotives and railcars has the potential to reduce fuel use. High-strength, lightweight components include aluminum, plastics, and others. Redesigns can also reduce railcar weight and reduce fuel use. 4.76% 4.76% N/A N/A Higher-capacity railcars that have better design and that use lightweight materials can carry more goods and also reduce energy use. However, current light-weight materials may be costly and may not have satisfactions at material characteristics, such as strength. Further research and development for advanced materials is needed.

210

Appendix B.5

Best Practice 2-5:

Lubrication Improvement

This best practice is assessed qualitatively. Table B-5 summarizes the assessment results in the standardized simplified reporting table format. Table B-5. Simplified Summary Table for Best Practice 2-5, Lubrication Improvement Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Lubrication Improvement Rail Rolling Resistance Improvement 26, 27, 30 8, 9, 10, 11, 12 CO2 Technology

Goal is to have all Class I locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would be both 4.0%. P Some energy expended by the locomotive is lost to wheel-to-rail friction. Reductions in wheel-to-rail resistance can be made via improved lubrication. Efficient lubrication systems, such as top-of-rail lubrication systems, reduce wheel and rail wear and reduce fuel consumption. These systems can avoid wheel slippage by distributing a proper amount of lubricants on the rail, so as to reduce wheel-to-rail resistance without causing slippage. 4.0% 4.0% N/A N/A The reduction of fuel use depends on the grade and curvature of railroads.

211

Appendix B.6

Best Practice 2-6:



Estimate of total number of vehicles or devices: Total number of locomotives for the rail mode is explained in Appendix B.1.A.

B.

Estimate of annual transport activity for the mode: Annual transport activity for the rail mode is explained in Appendix B.1.B.

C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is explained in Appendix B.1.C.

D.


Assumption:

i. The net life-cycle CO2 emissions reduction of B20 biodiesel is about 0.0069 tons CO2 eq. per 106 BTU, which is estimated in Appendix F.2.3.61 ii. Biodiesel industry was estimated to produce 1.7 billion gallons of B100 biodiesel in 2003, 3.5 billion gallons in 2015, and 10 billion gallons in 2030.63,64 Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons. iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heating value of petroleum diesel is 138,690 BTU/gallon.132-133 Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon.

212

Table B-6. Standardized Reporting Table for Best Practice 2-6, B20 Biodiesel Fuel for Locomotivesa Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description B20 Biodiesel Fuel for Locomotives Rail Alternative Fuels 23, 25, 26, 28, 29 8, 10 CO2 Technology

Goal is to have all Class I Locomotives participate. The reductions in modal GHG emissions and energy use in 2025 would be 5.50% (3.5 ×106 tons of CO2 eq.) and -5.31% (-42.3 ×1012 Btu), respectively. N The life-cycle CO2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO2 eq. per 106 BTU compared to that of petroleum diesel. Unit Value 109 ton-miles/year 2,312

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is 2,312 109 ton-miles/year Applicable (ATAP) Annual GHG Emissions Reductions(AGR) 106 ton CO2 eq./year 3.5 Annual Energy Use Reduction (AER) 1012 BTU /year -42.3 Annual Refrigerant Use Reduction (ARR) lbs/year N/A -3 Unit GHG Emissions Reductions (UGER) 10 lb CO2 eq./ton-mile 3.0 Unit Energy Use Reduction (UER) BTU /ton-mile 18.2 Unit Refrigerant Use Reduction (URR) lbs/ton-mile N/A Practice Costs Capital Cost I 106 USD ($) N/A Discount Rate I % 10% Technical Lifetime of Technology (L) years N/A Fixed Charge Factor (a) year-1 N/A Annual O & M Cost (AOM) $106 /year N/A 6 Annualized Cost (AC) $10 /year 382.5 Annual Energy Cost Saving (AECS) $106 /year 0 Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year -382.5 Net Savings per Unit of GHG Emissions Reductions -108.7 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU N/Ab Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years N/Ac a These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. 213

b c

This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. There is no pay-back period for this best practice because there is no net saving.

iv. In 2003, the truck mode consumed 4.6×1015 BTU of diesel.2,3 The rail mode consumed 0.531×1015 BTU of diesel.3 The water mode consumed 0.385×1015 BTU of distillate fuel.1,3 v. The potential market share of B20 biodiesel for the rail mode is estimated as 64.56% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes. (b)

Calculation:

i. Energy use for the rail mode in 2025 is estimated to be 0.79×1015 BTU. ii. Maximum B20 biodiesel production capacity for the rail mode in 2025 is estimated to be 0.51×1015 BTU. 0.79 × 10 15 BTU × 64.56% = 0.51 × 10 15 BTU

iii. The annual GHG emissions reductions are estimated to be 3.52×106 tons CO2 eq. in 2025. 0.51 × 10 15 BTU ×

(c)

E.

Results:

0.0069 CO 2 eq. 10 6 BTU

= 3.52 × 10 6 tons CO 2 eq.


Estimate of annual energy use reduction: i. Energy use reduction based on life cycle inventory is estimated to be -8.3%, which is estimated in Appendix A.33.E. ii. Energy use reduction based on life cycle inventory is estimated to be -4.2×1013 BTU − 8.3%. × 0.51 × 1015 BTU = −4.2 × 1013 BTU

214

F.

Estimate of unit GHG emissions reductions:  3.52 × 10 6 tons CO eq   2,000 lbs  0.0030 lb CO eq. 2 2  . ×  =  2312 × 10 9 ton − miles   ton  ton − mile  

G.


(

)

 − 4.2 × 10 7 10 6 BTU  − 18.2 BTU  . = 9 ton − mile  2312 × 10 ton − miles 

H.


I.


J.

Estimate of annualized cost: i. B20 biodiesel fuel price is estimated to be $0.75/106 BTU higher than the price of diesel fuel, which is estimated in Appendix A.33.J. ii. Annualized cost is estimated to be $382.5 ×106. $0.75 × 0.51 × 1015 BTU = $382.5 × 10 6 10 6 BTU

K.


L.


$0 − $382.5 × 10 6 = −$382.5 × 10 6

M.

Estimate of net savings per unit of GHG emissions reductions: − $382.5 × 10 6 3.52 × 10 tons CO 2 eq. 6

=

− $108.7 ton CO 2 eq. 215

N.


O.


216

APPENDIX C.

DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR AIR MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 6, including the simplified summary tables that their corresponding best practices are assessed qualitatively. Appendix C.1

Best Practice 3-1:

Surface Grooves

This best practice is assessed qualitatively. Table C-1 summarizes the assessment results in the standardized simplified reporting table format. Table C-1. Simplified Summary Table for Best Practice 3-1, Surface Grooves Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Surface Grooves Air Aerodynamic Drag Reduction 41, 42, 44 16, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.60%. P Skin friction drag, also referred to as viscous drag, is caused by the contact of the air flow against the surface of the aircraft, and is impacted by the viscosity property of air. An approach that is undergoing testing is the use of an adhesive-backed film with micro-grooves that is placed on the exterior surfaces of the wings and the fuselage of the airplane. The series of microscopic grooves produces a drag-reducing surface. The reduction in skin friction drag results in a decrease in fuel use. 1.60% 1.60% N/A N/A The disadvantage of this practice is that the lifetime of the film with micro-grooves is only 2 to 3 years. Thus, research is needed to improve the durability of the materials for the film.

217

Appendix C.2

Best Practice 3-2: Hybrid Laminar Flow Technology

This best practice is assessed qualitatively. Table C-2 summarizes the assessment results in the standardized simplified reporting table format. Table C-2. Simplified Summary Table for Best Practice 3-2, Hybrid Laminar Flow Technology Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Hybrid Laminar Flow Technology Air Aerodynamic Drag Reduction 41, 42, 44 16, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 6.00%. N Laminar flow is a smooth air flow moving across an airfoil without turbulence, but it is usually destroyed by turbulence induced because of interactions with wing surfaces, leading to skin friction. Furthermore, contamination on the aircraft surface, such as the accumulation of ice, insects or other debris, degrades laminar flow. A newly developed concept, hybrid laminar flow technology, integrates both passive and active approaches to maintain laminar flow. A passive device requires no energy for its operation. An active device requires a source of energy for its operation. Passive anti-contamination devices are used to prevent or minimize contamination. An example of a passive anti-contamination device is a Krueger flap. This flap has hinged droop surfaces on the leading edge of the wings that can be used for ice and insect-contamination prevention. An active approach, a suction system, is comprised of a multi-layer panel on a wing surface. The multi-layer panel includes a thin outer layer with fine pores and a thicker inner layer. The space between these two layers is divided into chambers. Air is sucked through the pores on the outer layer, and then is vented through ducts out of the aircraft. The ducts are located to avoid negative impact to the aerodynamic performance of the aircraft. The air suction process can reduce air flow turbulence to maintain laminar flow on the surface of a wing 6.00% 6.00% N/A N/A N/A 218

Appendix C.3

Best Practice 3-3:

Blended Winglet

This best practice is assessed qualitatively. Table C-3 summarizes the assessment results in the standardized simplified reporting table format. Table C-3. Simplified Summary Table for Best Practice 3-3, Blended Winglet Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Blended Winglet Air Aerodynamic Drag Reduction 41, 42 14, 16, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. C Lift-induced drag is due to the tip vortices produced by a lifting wing. A blended winglet is a commercially available wing-tip device that can reduce lift-induced drag. A winglet is an extension mounted at the tip of a wing. A blended winglet combines part of the wing tip with the winglet using a smooth blended shape that can decrease the tip vortex intensity. 2.00% 2.00% N/A N/A This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the surface area increase is accounted for in the estimate given here.

219

Appendix C.4

Best Practice 3-4:

Spiroid Tip

This best practice is assessed qualitatively. Table C-4 summarizes the assessment results in the standardized simplified reporting table format.

Attribute

Table C-4. Simplified Summary Table for Best Practice 3-4, Spiroid Tip Description



Spiroid Tip Air Aerodynamic Drag Reduction 41, 42 14, 16, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.65%. C An alternative type of wing-tip device is a spiroid tip. This device has been pilot tested and, like blended winglets, is intended to reduce lift-induced drag. A spiroid tip is a spiral loop formed by joining vertical and horizontal winglets. This technique can decrease tip vortex intensity and, therefore, reduce lift-induced drag. 1.65% 1.65% N/A N/A This practice increases the surface area of the wing of the aircraft, which could increase the viscous drag. The effect of additional viscous drag associated with the surface area increase is accounted for in the estimate given here.

220

Appendix C.5

Best Practice 3-5: Air Traffic Management Improvement

This best practice is assessed qualitatively. Table C-5 summarizes the assessment results in the standardized simplified reporting table format. Table C-5. Simplified Summary Table for Best Practice 3-5, Air Traffic Management Improvement Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Air Traffic Management Improvement Air Air Traffic Management 38, 39, 41, 45, 48, 49, 50, 51, 52, 53, 54 14, 15, 16, 17, 18, 19 CO2 Technology/ Operation

Goal is to have all aircrafts and all airports participate. The reductions in modal GHG emissions and energy use in 2025 would be both 6.00%. N Optimized air traffic management systems are in the development stage. Compared to the current air traffic control system, there are opportunities to reduce congestion, improve operational efficiency and improve aircraft routing in order to reduce fuel consumption. Advanced air traffic management systems can optimize air traffic flow, provide efficient route, airspace, and departure and landing procedure options, and increase situation awareness. 6.00% 6.00% N/A N/A N/A

221

Appendix C.6

Best Practice 3-6: Airframe Weight Reduction

This best practice is assessed qualitatively. Table C-6 summarizes the assessment results in the standardized simplified reporting table format. Table C-6. Simplified Summary Table for Best Practice 3-6, Airframe Weight Reduction Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Airframe Weight Reduction Air Weight Reduction 41, 42, 44, 48, 50, 51 16, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. P The weight of an airframe is approximately 50% of an aircraft’s gross weight. Adoption of advanced lighter and stronger materials in the structural components of the airframe, such as aluminum alloy, titanium alloy, and composite materials for non-load-bearing structures, can reduce airframe weight, thereby leading to a reduction in fuel use. 2.00% 2.00% N/A N/A More research and development is needed to reach the projected structure weight reduction target.

222

Appendix C.7

Best Practice 3-7: Non-Essential Weight Reduction

This best practice is assessed qualitatively. Table C-7 summarizes the assessment results in the standardized simplified reporting table format. Table C-7. Simplified Summary Table for Best Practice 3-7, Non-Essential Weight Reduction Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Non-Essential Weight Reduction Air Weight Reduction 38, 39, 41, 42, 44, 45, 46 14, 15, 17, 18, 19 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.00%. N Trimming non-essential weight from aircraft can reduce fuel use. Adjustments to the amount of fuel, water, and emergency equipment onboard with respect to anticipated requirements and a contingency allowance can reduce fuel use 1.00% 1.00% N/A N/A N/A

223

Appendix C.8

Best Practice 3-8: Ground-Based Equipment as an Alternative to Auxiliary Power Units

This best practice is assessed qualitatively. Table C-8 summarizes the assessment results in the standardized simplified reporting table format. Table C-8. Simplified Summary Table for Best Practice 3-8, Ground-Based Equipment as an Alternative to Auxiliary Power Units Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Ground-Based Equipment as an Alternative to Auxiliary Power Units Air Ground Support Equipment Improvement 38, 39, 41, 42, 44 14, 15, 17, 18 CO2 Technology

Goal is to have all aircrafts and airports participate. The reductions in modal GHG emissions and energy use in 2025 for Best Practices 3-8 and 3-9 would be both 2.94%. P Aircraft auxiliary power units (APUs) are engine-driven generators that supply electricity for use aboard the plane while at a cargo loading area. An alternative method for supplying electricity is to connect the aircraft to shore-based power or to use ground-based equipment to generate power for delivery to the aircraft. Such ground-based equipment has been pilot tested. Ground-based equipment can reduce APU fuel use significantly while the aircraft is at the gate. 2.94%(for Best Practices 3-8 and 3-9) 2.94%(for Best Practices 3-8 and 3-9) N/A N/A This strategy can only be used when aircrafts are parked at gates.

224

Appendix C.9

Best Practice 3-9:

Electric or Hybrid Heavy Duty Delivery Trucks

This best practice is assessed qualitatively. Table C-9 summarizes the assessment results in the standardized simplified reporting table format. Table C-9. Simplified Summary Table for Best Practice 3-9, Electric or Hybrid Heavy Duty Delivery Trucks Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Electric or Hybrid Heavy Duty Delivery Trucks Air Ground Support Equipment Improvement 39, 45, 46 15, 16, 17, 18, 19 CO2 Technology

Goal is to have all aircrafts and aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 for Best Practices 3-8 and 3-9 would be both 2.94%. P Off-road electric or hybrid vehicles for supporting airport operations have been pilot-tested. Such vehicles can replace existing, older ground support equipment. An off-road electric powered delivery vehicle can operate for 100 miles after a single charge, carry 3,000 lbs of cargo, travel at a speed of up to 30 miles per hour, and climb grades up to 10%. These capabilities are suitable for ground equipment service. Other alternative ground support equipment propulsion systems can be based on LPG or gasoline powered hybrid vehicles. 2.94 % (for Best Practices 3-8 and 3-9) 2.94% (for Best Practices 3-8 and 3-9) N/A N/A Reduction in cost is needed to expand the market penetration potential of this practice.

225

Appendix C.10

Best Practice 3-10: Improved Engine Overall Efficiency

This best practice is assessed qualitatively. Table C-10 summarizes the assessment results in the standardized simplified reporting table format. Table C-10. Attribute

Simplified Summary Table for Best Practice 3-10, Improved Engine Combustion Efficiency Description



Improved Engine Overall Efficiency Air Engine Improvement 41, 42, 43, 46, 47 14, 17 CO2 Technology

Goal is to have all aircrafts participate. The reductions in modal GHG emissions and energy use in 2025 would be both 13.00%. C Current aircraft energy efficiency, the amount of energy used to transport one unit of payload over a distance, is about 10-13 MJ per ton-mile. Aircraft fuel consumption can be reduced based on improving engine efficiency. Engine efficiency can be improved through increasing fan bypass ratio, increasing pressure ratio of compressor and better mixing of fuel and air prior to combustion. A new jet engine with several advanced technologies is being developed and is scheduled to enter the market in 2008. This engine features larger fan for high engine bypass ratio, a compressor for high pressure ratio, and better mixing of fuel and air, which leads to a more fuel-efficient engine. 13.00% 13.00% N/A N/A N/A

226

APPENDIX D.

DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR WATER MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 7, including the standardized reporting tables, if their corresponding best practices can be assessed quantitatively, or the simplified summary tables, if their corresponding best practices are assessed qualitatively. For those assessed quantitatively, the methods for the estimation of data in the standardized reporting tables are also described. Appendix D.1

Best Practice 4-1: Off-Center Propeller

This best practice is assessed qualitatively. Table D 4-1 summarizes the assessment results in the standardized simplified reporting table format. Table D-1. Simplified Summary Table for Best Practice 4-1, Off-Center Propeller Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Off-Center Propeller Water Propeller System Improvement 58, 59 20, 22, 23 CO2 Technology

Goal is to have half of all ships participate. The reductions in modal GHG emissions and energy use in 2025 would be both 1.50%. C Vortices that are formed along the rear part of the ship and that flow into the wake are the result of turbulence. Such vortices are referred to as “bilge vortices” and they effectively increase the resistance of water movement around the ship hull. An off-center propeller is a commercially available device that attempts to capture some of the flow and energy contained within the bilge vortices to enhance propulsion efficiency. An off-center propeller is part of a system that includes the rudder and properly shaft located away from the longitudinal centerline of the ship. 1.50% 1.50% N/A N/A This practice can be implemented for new ships but is difficult or impractical to retrofit to existing ships. 227

Appendix D.2

Best Practice 4-2: Propeller Boss Cap with Fins

This best practice is assessed qualitatively. Table D 4-2 summarizes the assessment results in the standardized simplified reporting table format. Table D-2. Simplified Summary Table for Best Practice 4-2, Propeller Boss Cap with Fins Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Propeller Boss Cap with Fins Water Propeller System Improvement 58, 59 20, 22, 23 CO2 Technology

Goal is to have half of all ships participate. The reductions in modal GHG emissions and energy use in 2025 would be both 2.00%. C Turbulent vortices are generated by propeller rotation. The formation of vortices requires energy. Thus, energy that could be used for propulsion is diverted to the formation of vortices, which reduces the overall energy efficiency of the propulsion system. A method for reducing the formation of vortices associated with the propeller ration is the use of a propeller boss cap with fins (PBCF). The PBCF includes small fins installed behind the propeller and that rotates in the same direction as the propeller. The purpose of these fins is to avoid the formation of vortices. 2.00% 2.00% N/A The estimated capital cost of PBCF ranges from $20,000 for 735 kW engine to $146,000 for 22,050 kW engine, which can be recovered within two years by fuel cost savings N/A

228

Appendix D.3

Best Practice 4-3: Auxiliary Free-rotating Propulsion Device behind the Main Propellers

This best practice is assessed qualitatively. Table D 4-3 summarizes the assessment results in the standardized simplified reporting table format. Table D-3. Simplified Summary Table for Best Practice 4-3, Auxiliary Free-Rotating Propulsion Device behind the Main Propellers Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Auxiliary Free-Rotating Propulsion Device behind the Main Propellers Water Propeller System Improvement 58, 59 20, 22, 23 CO2 Technology

Goal is to have half of all ships participate. The reductions in modal GHG emissions and energy use in 2025 would be both 3.00%. C Propeller rotation results in the formation of energy-consuming turbulent vortices unless mitigating measures are implemented. An alternative to PBCF is a grim vane wheel (GVW). It is an auxiliary free-rotating propulsion device that has vanes with larger diameter than that of propeller and is located immediately behind the main propeller. The rotation of GVW modifies the accelerated flow of water that is leaving the propeller, recovers a portion of the energy embodied in the accelerated flow of water, and in so doing provides extra propulsion. Older designs of GVW are mounted on the propeller shaft, but can have problems with mechanical failure. A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability. 3.00% 3.00% N/A The estimated capital cost of new-designed GVW is approximately $1.2 million dollars, which can be recovered in about three years based on fuel cost savings. A newly designed GVW system can be mounted on the rudder horn instead of propeller shaft, which may improve reliability.

229

Appendix D.4

Best Practice 4-4:

Shoreside Power for Marine Vessels at Ports

This best practice is assessed qualitatively. Table D 4-4 summarizes the assessment results in the standardized simplified reporting table format. Table D-4. Simplified Summary Table for Best Practice 4-4, Shoreside Power for Marine Vessels at Ports Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Shoreside Power for Marine Vessels at Ports Water Anti-Idling 56, 58, 59 20, 21, 23, 24 CO2 Technology

Goal is to have 60% of all ships participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.16% and -0.04%. P Shoreside power is being tested as ship anti-idling system that can avoid the need for running the ship auxiliary engine continuously while a ship is docked at a port. Shoreside power is a system that connects the ship to an external electrical power source, thereby avoiding the need for use of the auxiliary engine. Thus, this system can reduce ship fuel use and GHG emissions. 0.16% -0.04% N/A N/A This practice can reduce GHG emissions and criteria air pollutions at ports. It can avoid the need for use of the on-board auxiliary engine. However, the fuel use for the auxiliary engine is only a small fraction of total marine fuel use.

230

Appendix D.5

Best Practice 4-5: B20 Biodiesel Fuel for Ships

This best practice is assessed quantitatively. Table D-5 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained. A.

Estimate of total number of vehicles or devices: (Not available: this value is not estimated in this study).

B.


Assumption:

i. It is estimated that total transport activity hauled by domestic water mode in the U.S. in 2003 is 606 × 109 ton-miles.141-142 ii. It is estimated that total transport activity hauled by oceangoing ships in the world in 2003 is 25,844 × 109 ton-miles.143 iii. International marine fuel consumption is estimated to be 284× 106 metric tons, 71% of international marine fuel consumption is used for freight activities, and 70% of marine fuel is residual fuel oil and 30% is distillate fuel oil.144 iv. International marine bunker fuel purchased from the U.S. in 2003 is estimated to be 321.7× 1012 BTU.1 v. The ratio of international marine transport activity in the U.S. to international marine transport activity in the world is proportional to the ratio of energy use for marine transport activity in the U.S. and that in the world. vi. The growth rate of total transport activity is the same as the growth rate of energy use for the water mode.

231

Table D-5. Standardized Reporting Table for Best Practice 4-5, B20 Biodiesel Fuel for Shipsa Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description B20 Biodiesel Fuel for Ships Water Alternative Fuel 58, 61 23, 25 CO2 Technology

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) Annual O & M Cost (AOM) 232

Goal is to have all ships using distillate fuel participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.22% (1.5 ×106 tons of CO2 eq.) and -1.25% (-18 ×1012 Btu), respectively. N The life-cycle CO2 emissions coefficient of B20 biodiesel decreases by 0.0069 tons CO2 eq. per 106 BTU compared to that of land-use petroleum diesel fuel. Land-use diesel fuel and marine gas oil belong to distillate fuel except that the land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO2. Since removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. Thus, the latter provides a useful upper bound of the former. Unit Value 109 ton-miles/year 2,027 109 ton-miles/year

591


1.5 -18 N/A 5 -31 N/A

106 USD ($) % years year-1 $106 /year

N/A 10% N/A N/A N/A

a b c

Annualized Cost (AC) $106 /year 178 Annual Energy Cost Saving (AECS) $106 /year 0 6 Annual Refrigerant Cost Saving (ARCS) $10 /year N/A Net Savings (NS) $106 /year -178 Net Savings per Unit of GHG Emissions Reductions $/ton CO2 eq. -120 (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU N/Ab Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years N/Ac These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025. This practice has no energy use reduction due to an increase in energy use, and it has no net saving due to high annualized cost and no energy cost saving. There is no pay-back period for this best practice because there is no net saving.

(b) Calculation:

i. Fuel use for international marine freight transportation in 2003 is estimated to be 8.5× 1015 BTU.  2,205 lb   19,600 BTU   19,011 BTU    +  70% ×   ×  30% × lb lb     metric tons  

(284 ×10

6

)

metric tons × 71% = 8.5 × 10 15 BTU

ii. The ratio of international marine transport activity in the U.S. to international marine transport activity in the world is estimated to be 3.8% 321.7 × 10 12 BTU = 3 .8 % 8.5 × 10 15 BTU

iii. Total transport activity hauled by oceangoing ships in the U.S. in 2003 is estimated to be 982 × 109 ton-miles.143

(25,844 × 10 (c)

2003 Results:

9

)

× 3.8% ton − miles = 982 × 10 9 ton − miles

The estimated total transport activity for the water mode in the U.S. in 2003 is 1,588 ×109 ton-miles.

233

(606 × 10 (d) 2025 Results:

C.

9

)

+ 982 × 10 9 ton − miles = 1,588 × 10 9 ton − miles

Since total energy use for the water mode is estimated to grow by 27.7% from 2003 to 2025,4 the estimated total transport activity for the water mode in the U.S. in 2025 will be 2,027 ×109 ton-miles.

Estimate of annual transport activity to which a practice is applicable: Assumption: i. Distillate fuel use for domestic water trade in the U.S. is estimated to be (a) 35% of total fuel use for domestic water trade in the U.S. in 2003.3 ii. Distillate fuel use for oceangoing bunker fuel purchased in the U.S. is estimated to be 26% of total fuel use for oceangoing bunker fuel purchased in the U.S. in 2003.1 iii. The ratio of marine transport activity powered by distillate fuel to marine transport activity powered by total marine fuel is proportional to the ratio of distillate fuel use for marine transport activity to total fuel use for marine transport activity. iv. The growth rate of transport activity to which this practice is applicable is the same as the growth rate of energy use for the water mode. (b) Calculation:

The estimated total marine transport activity powered by distillate fuel in the U.S. in 2003 is 463 ×109 ton-miles.

((606 × 10

9

) (

× 35% + 982 × 10 9 × 26%

)) ton − miles

= 463 × 10 9 ton − miles

(d) Results:

D.

Since total energy use for the water mode is estimated to grow by 27.7% from 2003 to 2025, 4 the estimated total marine transport activity powered by distillate fuel in the U.S. in 2025 will be 591 ×109 ton-miles.


Assumption:

i. The net life-cycle CO2 emissions reduction of B20 biodiesel is about 0.0069 tons CO2 eq. per 106 BTU compared to land-use 234

diesel fuel , which is estimated in Appendix F.2.3.61 ii. Biodiesel industry was estimated that it has the potential to produce 1.7 billion gallons of B100 biodiesel in 2003, 3.5 billion gallons of B100 biodiesel in 2015, and 10 billion gallons of B100 biodiesel in 2030.63,64 Thus, the estimated production of B100 biodiesel in 2025 is 7.8 billion gallons. iii. The estimated heating value of B100 biodiesel is 126,789 BTU/gallon, and the estimated heating value of petroleum diesel is 138,690 BTU/gallon.132-133 Thus, the estimated heating value of B20 biodiesel is 136,310 BTU/gallon. iv. The truck mode consumed 4.6×1015 BTU of diesel fuel in 2003.2,3 The rail mode consumed 0.531×1015 BTU diesel in 2003.3 The water mode consumed 0.385×1015 BTU distillate fuel oil in 2003.1,3 v. The potential market share of B20 biodiesel for the water mode is estimated as 25.7% in 2025 based on the potential maximum production capacity of biodiesel, which is estimated as 7.8 billion gallons in 2025, and the distribution ratio among the truck, rail and water modes. vi. Land-use diesel fuel and marine gas oil are both distillate fuels but differ in that land-use diesel fuel has a much lower sulfur level than the marine gas oil. Sulfur concentrations in distillate fuels can be reduced by a refining process, hydro-treating, that consumes energy and emits CO2.111 vii. Since marine gas oil is high sulfur diesel fuel and removal of sulfur emits more GHG, the production of marine gas oil emits less GHG than the production of land-use diesel fuel based on life cycle inventories. The difference of life cycle GHG emission analysis results between B20 biodiesel and marine gas oil should be lower than the difference between B20 biodiesel and land-use diesel fuel. Thus, the latter provides a useful upper bound of the former. viii. Energy use for the water mode in 2025 is estimated to be 235

1.43×1015 BTU.1,3 ix. For marine fuel consumption, residual fuel oil for freight ships is about 60% of total marine fuel use. Distillate fuel for freight ships is about 11% of total marine fuel use. Distillate fuel for other ships (such as passenger ships, fish ships, military ships) accounts for other 29% of marine fuel use.112 Thus, distillate fuel for freight ships is estimated to be 15% of total fuel for freight ships. (b)

Calculation:

i. Even though maximum B20 biodiesel production capacity for the water mode in 2025 may reach 25.7% of total fuel for freight ships, but only 15% of total fuel for freight ships are distillate fuel. ii. Maximum B20 biodiesel for the water mode in 2025 is estimated to be 0.215×1015 BTU. 1.43 × 1015 BTU × 15% = 0.215 × 1015 BTU

iii. The annual GHG emissions reductions are estimated to be 1.48×106 tons CO2 eq. in 2025. 0.215 × 1015 BTU ×

(c)

E.

Results:

0.0069 CO 2 eq. 6

10 BTU

= 1.48 × 10 6 tons CO 2 eq.


Estimate of annual energy use reduction: i. Energy use reduction based on life cycle inventory is estimated to be -8.3%, which is estimated in Appendix A.33.E. ii. Energy use reduction based on life cycle inventory is estimated to be -1.8×1013 BTU − 8.3%. × 0.215 × 1015 BTU = −1.8 × 1013 BTU

F.

Estimate of unit GHG emissions reductions:

236

 1.48 × 10 6 tons CO eq   2,000 lbs  0.0050 lb CO eq. 2 2  . ×  =  591 × 10 9 ton − miles   ton  ton − mile  

G.


H.


I.


J.

Estimate of annualized cost: i. The average fuel cost of B100 Biodiesel in April 2005 is estimated to be $22.2 per 106 BTU.137

 − 1.8 × 10 7 (10 6 BTU )  − 30.5 BTU  . = 9 ton − mile  591 × 10 ton − miles 

ii. High sulfur diesel fuel price in 2025 is the same as the price of the second season of 2005, which is $18.03/106 BTU.115 iii. Thus, B20 biodiesel fuel price is estimated to be $18.86/106 BTU, which is $0.83/106 BTU higher than the price of high sulfur diesel fuel. iv. Annualized cost is estimated to be $178 ×106. $0.83 × 0.215 × 1015 BTU = $178 × 10 6 10 6 BTU

K.


L.


$0 − $178 × 10 6 = −$178 × 10 6

237

M.

Estimate of net savings per unit of GHG emissions reductions: − $178 × 10 6 1.48 × 10 tons CO 2 eq. 6

=

− $120.4 ton CO 2 eq.

N.


O.


238

APPENDIX E.

DETAILS OF INPUT DATA, ASSUMPTIONS, AND ESTIMATION RESULTS FOR PIPELINE MODE BEST PRACTICES

This appendix is additional descriptive information for the best practices in Chapter 8, including the standardized reporting tables, if their corresponding best practices can be assessed quantitatively, or the simplified summary tables, if their corresponding best practices are assessed qualitatively. For those assessed quantitatively, the methods for the estimation of data in the standardized reporting tables are also described. Appendix E.1

Best Practice 5-1: Instrument Air

Convert Natural Gas Pneumatic Controls to

This best practice is assessed quantitatively. Table E-1 summarizes the assessment results. This table is in the format of the standardized reporting table for quantitative results. The basis of the quantitative estimates is explained. A.


B.

Assumption:

The growth rate of pneumatic control devices is the same as the growth rate of total GHG emissions for the pipeline mode.

(b) 2003 Results:

It is estimated that there were 110,000 pneumatic control devices in the pipeline mode in 2003.117

(c)

Since total GHG emissions for the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, which is explained in Section 1.2, there will be 126,100 pneumatic control devices in 2025.

2025 Results:


Assumption:

The growth rate of total transport activity is the same as the growth rate of total GHG emissions for the pipeline mode.

(b) 2003 Results:

It is estimated that there were 335×109 ton-miles in 2003.3

(c)

Since total GHG emissions the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, which is explained in Section 1.2, there will be 384 ×109 ton-miles in 2025.

2025 Results:

239

Table E-1. Standardized Reporting Table for Best Practice 5-1, Convert Natural Gas Pneumatic Controls to Instrument Aira Characteristics of the Practice

Description Convert Natural Gas Pneumatic Controls to Instrument Air Pipeline Process Control Device Improvement


70, 71, 72, 73 26, 27, 28 CH4 Technology

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) Annual O & M Cost (AOM) Annualized Cost (AC) Annual Energy Cost Saving (AECS) 240

Goal is to have 10% of natural gas-powered pneumatic control systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.50% (0.65 ×106 tons of CO2 eq.) and 0.13% (1.20 ×1012 Btu), respectively. C Pneumatic control systems for pipelines are currently operated using pressurized natural gas. However, pneumatic controls based on compressed air could be used instead. Since natural gas is continuously bled from the current control devices, they are one of the largest methane emissions sources in the natural gas industry. Conversion of pneumatic control systems from natural gas to compressed air would reduce methane emissions Unit Value 109 ton-miles/year 384 109 ton-miles/year 6

384


0.65 1.20 N/A 3.4 3.1 N/A

106 USD ($) % years year-1 $106 /year $106 /year $106 /year

3.7 10% 15 0.131 1.2 1.7 13.2

a

Annual Refrigerant Cost Saving (ARCS) $106 /year N/A Net Savings (NS) $106 /year 11.5 Net Savings per Unit of GHG Emissions Reductions 17.6 $/ton CO2 eq. (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 9.6 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 0.31 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

C.

Estimate of annual transport activity to which a practice is applicable: Annual transport activity to which this practice is applicable is the same as the total ton-miles of this mode, which is explained in Appendix E.1.B.

D.


Assumption:

i. Total GHG emissions reductions are due to methane emission reduction. ii. The natural gas pipeline mode emits 38.3 ×106 tons CO2 by using energy and emits 74.9 ×106 tons CO2 eq. of methane in 2003 because of the leakage of natural gas.1 Thus, the pipeline mode emits 113.2×106 tons CO2 eq. of GHG in 2003. Since the pipeline mode is estimated to grow by 15% from 2003 to 2025, there will be 129.6 ×106 tons CO2 eq. of GHG for the pipeline mode in 2025. iii. Pneumatic control devices in the natural gas industry is estimated to emit 949 Gg of methane in 2003.1 iv. The pipeline mode in the natural gas industry is its transmission sector, which emit 26% of methane.117 v. Approximately 10% of pneumatic control systems powered by natural gas are assumed to be replaced by pneumatic control systems powered by compressed instrument air. Thus, 12,610 of pneumatic control devices are estimated to be replaced in 2025.

241

vi. Since pneumatic control systems powered by compressed instrument air consume electricity,12,610 of pneumatic control devices are estimated to consume 11×106 kWh of electricity.117 vii. The estimated emission factor for electricity is 0.0007 tons CO2 eq. per kWh.108 (b)

Calculation:

i. Pneumatic control devices for the pipeline mode are estimated to emit 5.71×106 tons CO2 eq. of GHG in 2003.

 21 CO 2 eq. 10 9 g lb Ton   949 Gg CH × 26% × × × × 4  CH 4 Gg 453.6 g 2,000 lb   = 5.71× 10 6 Tons CO 2 eq.

ii. Since the pipeline mode is estimated to grow by 15% from 2003 to 2025, there will be 6.55 ×106 tons CO2 eq. of GHG emitted from the pneumatic control devices in 2025.

5.71× 10 6 Tons CO 2 eq. × 15% = 6.55 × 10 6 Tons CO 2 eq. iii. Total methane emissions reductions in 2025 due to the replacement of 10% of pneumatic control devices are estimated to be 0.655×106 tons CO2 eq. 6.55 × 10 6 tons CO 2 eq. × 10% = 0.655 × 10 6 tons CO 2 eq.

iv. Total GHG emissions due to using electricity to power 12,610 of pneumatic control devices are estimated to be 0.008 ×106 tons CO2 eq. v. Thus, total GHG emissions reductions are estimated to be 0.65×106 tons CO2 eq. in 2025.

0.655 × 10 6 Tons CO 2 eq. − 0.008 × 10 6 Tons CO 2 eq. = 6.5 × 10 6 Tons CO 2 eq. (c)

Results:

The annual GHG emissions reductions are estimated to be 242

0.65×106 tons CO2 eq. in 2025.

E.

Estimate of annual energy use reduction: (a) Assumption: i. Total energy use reduction is that natural gas emission reduction minuses energy for producing electricity for operating this practice. ii. 1 lb of natural gas contains 21,300 BTU of energy, which is explained in Appendix F.1.6. iii. 1 kWh is equal to 3,412 BTU. iv. The ratio of primary energy input to electricity output is estimated to be 2.89 based on total electricity generated and total primary energy consumed in the U.S. in 2005.133 (b) Calculation:

i. Natural gas emission reduction in 2025 for adopting this practice is estimated to be 1.33×1012 BTU. 9  21,300 BTU   × 115%  949 Gg CH 4 × 26% × 10% × 10 g × lb ×   Gg 453 . 6 g lb   12 = 1.33 × 10 BTU.

ii. Primary energy needed for producing electricity in order to operate this practice in 2025 is estimated to be 0.11×1012 BTU.

11× 106 kWh ×

3412 BTU kWh

× 2.89 = 0.11× 1012 BTU

iii. The estimated annual energy use reduction in 2025 is 1.2×106 (106 BTU).

(

)

1.33 × 1012 BTU − 0.11× 1012 BTU = 1.2 × 106 106 BTU (c) Results:

F.

The estimated annual energy use reduction in 2025 is 1.2 ×106 (106 BTU).

Estimate of unit GHG emissions reductions:

243

 0.65 × 10 6 tons CO 2 eq   2,000 lbs  0.0034 lb CO 2 eq.      384 × 10 9 ton − miles . ×  ton  = ton − mile    

G.


(

)


H.

Estimate of capital cost i. The capital cost for this practice for a facility is estimated to be $50,000, and this practice in this facility reduces natural gas emissions by 0.02 billion cubic feet (BcF).117 ii. Natural gas emission reduction from adopting this practice for the pipeline mode is estimated to be 1.5 BcF in 2025. 9  0.04246 lbs   × 115%  949 Gg CH 4 × 26% × 10% × 10 g × lb ×   Gg 453 . 6 g lb   = 1.5 BcF.

iii. Total capital costs for adopting this practice in 2025 are estimated to be $3.7 ×106. $50,000 ×

I.

1.5 BcF 0.02 BcF

= $3.7 × 10 6

Estimate of annual O & M cost i. The annual O & M cost for this practice for a facility is estimated to be $3,200, and this practice in this facility reduces natural gas emissions by 0.02 billion cubic feet (BcF).117 ii. The annual electricity cost for this practice for a facility is estimated to be $13,140, and this practice in this facility reduces natural gas emissions by 0.02 billion cubic feet (BcF).117 iii. Natural gas emission reduction from adopting this practice for the pipeline mode is estimated to be 1.5 BcF in 2025, which is estimated in Appendix F.1.H. iv. The annual O & M costs, which include the electricity cost, for adopting this practice 244

in 2025 are estimated to be $1.2 ×106.

($13,140 + $3,200) ×

J.

1.5 BcF 0.02 BcF

= $1.2 × 10 6


1   1 ∑  i =1  (1 + 0.1)i   15

   

= 0.131

iii. Annualized cost is estimated to be $1.7 ×106 in 2025.

($3.7 × 10 K.

6

)

× 0.131 + $$1.2 × 10 6 = $1.7 × 10 6

Estimate of energy cost reduction: (a) Assumption: i. Natural gas price in 2025 is the same as the price of September 2005, which is $10.26 per thousand cubic feet. 114 ii. Heating value of natural gas is estimated to be 1,031 BTU per cubic feet.145 ii. Thus, natural gas price in 2025 is estimated to be $9.95/106 BTU. (b)

Calculation:

i. Natural gas reduction is estimated to be 1.33×1012 BTU, which is estimated in Appendix E.1.E. ii. The estimated energy cost reduction in 2025 is $13.2 ×106. 1.33 × 10 6 (10 6 BTU )×

(c) L.

Results:

$9.95 = $13.2 × 10 6 6 10 BTU



$13.2 × 10 6 − $1.7 × 10 6 = $11.5 × 10 6 245

M.


$11.5 ×10 6 0.65 ×10 6 tons CO 2 eq. N.

=

$17.6 ton CO 2 eq.


O.

Estimate of simple payback period: $3.7 × 10 6 ($13.2 × 10 6 − $1.2 × 10 6 ) = 0.31 years

246

Appendix E.2

Best Practice 5-2: Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices



Assumption:

(b) 2003 Results:

Annual per-device GHG emissions in 2025 are the same as annual per-device GHG emissions in 2003 for the pipeline mode. i. It is estimated that there were 110,000 pneumatic control devices in the pipeline mode in 2003.117 ii. Approximately 26% of pneumatic control devices are high-bleed devices. iii. Thus, it is estimated that there were 28,600 high-bleed pneumatic control devices in the pipeline mode in 2003.

(c)

B.

2025 Results:

Since total GHG emissions for the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, which is explained in Section 1.2, there will be 32,800 high-bleed pneumatic control devices in 2025.

Estimate of annual transport activity for the mode: Annual transport activity for this mode is explained in Appendix E.1.B.

C.


247

Table E-2. Standardized Reporting Table for Best Practice 5-2, Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devicesa Characteristics of the Practice

Description Replace High-Bleed Natural Gas Pneumatic Devices with Low-Bleed Pneumatic Devices Pipeline Process Control Device Improvement


70, 71, 72, 73 26, 27, 28 CH4 Technology

Practice Goals


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) Annual O & M Cost (AOM) Annualized Cost (AC) Annual Energy Cost Saving (AECS) Annual Refrigerant Cost Saving (ARCS) Net Savings (NS) Net Savings per Unit of GHG Emissions Reductions (NSGR) Net Savings per Unit of Energy Use Reduction (NSER) Net Savings per Unit of Refrigerant Use Reduction (NSRR) 248

Goal is to have 26% of natural gas-powered pneumatic control systems participate. The reductions in modal GHG emissions in 2025 would be 0.57% (0.75 ×106 tons of CO2 eq.) and 0.16% (1.5 ×1012 Btu), respectively. C High-bleed pneumatic control systems are based on high-bleed compressed methane. An alternative designed is based on low-bleed compressed methane that reduces methane emission. Unit Value 9 10 ton-miles/year 384 109 ton-miles/year

384


0.75 1.5 N/A 3.9 3.9 N/A

106 USD ($) % years year-1 $106 /year $106 /year $106 /year $106 /year $106 /year

13.6 10% 15 0.131 N/A 1.8 15.0 N/A 13.2

$/ton CO2 eq.

17.8

6

$/10 BTU

8.8

$/lb

N/A

a

Simple Payback Period (SPP) years 0.91 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

D.


Assumption: i. Total GHG emissions reductions are due to methane emission reduction. ii. Approximately 86% of high-bleed pneumatic control devices are level controllers, and a level controller is estimated to averagely emit 66.6×103 cubic feet of methane per year.118 iii. Approximately 14% of high-bleed pneumatic control devices are pressure controllers, and a pressure controller is estimated to averagely emit 91.2×103 cubic feet of methane per year.118 iv. The replacement of high-bleed pneumatic control devices by low-bleed pneumatic control devices reduce methane emissions by 90%.119 v. Approximately 80% of high-bleed pneumatic control systems can be replaced by low-bleed pneumatic control systems.118

(b) Calculation:

i. Total methane emission reduction is estimated to be 1.67 BcF in 2003.

[(66.6 × 10

3

) (

)]

ft 3 × 86% + 91.2 × 10 3 ft 3 × 14% × 90% × (32,800 × 80%)

= 1.67 BcF ii. Total methane emission reduction is estimated to be 0.745×106 tons CO2 eq. in 2003.

 0.04246 lbs 21 CO 2 eq. Ton  1.67 BcF × × ×  CH 4 2,000 lb  ft 3  = 0.745 × 10 6 Tons CO 2 eq. (c)

Results:


249

E.

Estimate of annual energy use reduction: The estimated annual energy use reduction in 2025 is 1.5 ×1012 BTU.

0.04246 lbs 21,300 BTU   1.67 BcF ×  = 1.5 × 1012 BTU × 3   lb ft  

F.

Estimate of unit GHG emissions reductions:  0.745 × 10 6 tons CO 2 eq   2,000 lbs  0.0039 lb CO 2 eq.      384 × 10 9 ton − miles . ×  ton  = ton − mile    

G.


(

)


H.

Estimate of capital cost i. The capital cost for a level controller is estimated to be $380, and the capital cost for a pressure controller is estimated to be $1,340.118 ii. Total capital costs for adopting this practice in 2025 are estimated to be $13.6 ×106.

[($380 × 86% ) + ($1,340 × 14% )]× (32,800 × 80% ) = $13.6 × 10 6 I.

Estimate of annual O & M cost The O & M cost of a low-bleed device is estimated to be the same as the O & M cost of a high-bleed device. Thus, the change of the O & M cost for this practice is zero.

J.

Estimate of annualized cost: i. The life-time of this practice is estimated to be 15 years. ii. Fixed charge factor is estimated to be 0.131.

250

Fixed ch arg e factor (a ) =

1  15  1 ∑  i =1  (1 + 0.1)i  

   

= 0.131


($13.6 × 10 K.

6

)

× 0.131 = $1.78 × 10 6

Estimate of energy cost reduction: (a) Assumption: Natural gas price in 2025 is estimated to be $9.95/106 BTU, which is estimated in Appendix E.1.K. (b)

Calculation:


(c) L.

Results:

$9.95 = $15.0 × 10 6 6 10 BTU



$15.0 × 10 6 − $1.78 × 10 6 = $13.24 × 106

M.


$13.24 × 10 6 0.745 × 10 6 tons CO 2 eq. N.

=

$17.8 ton CO 2 eq.


O.

Estimate of simple payback period: $13.6 × 10 6 ($15.0 × 10 6 ) = 0.91 years 251

Appendix E.3

Best Practice 5-3:

“Hot Tap” Method



B.

Assumption:

The growth rate of total pipeline length is the same as the growth rate of total GHG emissions for the pipeline mode.

(b) 2003 Results:

It is estimated that there were 285,165 miles of pipelines for the pipeline mode in 2003.1

(c)

Since total GHG emissions for the pipeline mode is estimated to grow by 14.6% from 2003 to 2025, which is explained in Section 1.2, there will be 326,900 miles of pipelines in 2025.

2025 Results:

Estimate of annual transport activity for the mode: Annual transport activity for this mode is explained in Appendix E.1.B.

C.


D.


Assumption:

i. Total GHG emissions reductions are due to methane emission reduction. ii. A Canadian natural gas company, which own 23,000 miles of pipelines, adopted this practice and reduce methane by 8.4×103 tons per year.121

252

Table E-3. Standardized Reporting Table for Best Practice 5-3, “Hot Tap” Method a Characteristics of the Practice Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type

Description “Hot Tap” Method Pipeline Connecting Method 70, 71, 72, 73 26, 27, 28, 29 CH4 Technology


Emissions, Energy Use, and Refrigerant Use Annual Transport Activity for the Mode (ATAM) Annual Transport Activity to Which a Practice Is Applicable (ATAP) Annual GHG Emissions Reductions(AGR) Annual Energy Use Reduction (AER) Annual Refrigerant Use Reduction (ARR) Unit GHG Emissions Reductions (UGER) Unit Energy Use Reduction (UER) Unit Refrigerant Use Reduction (URR) Practice Costs Capital Cost (C) Discount Rate (r) Technical Lifetime of Technology (L) Fixed Charge Factor (a) Annual O & M Cost (AOM) Annualized Cost (AC) Annual Energy Cost Saving (AECS) Annual Refrigerant Cost Saving (ARCS) Net Savings (NS) Net Savings per Unit of GHG Emissions Reductions (NSGR) 253

Goal is to have all pipeline systems participate. The reductions in modal GHG emissions in 2025 would be 1.93% (2.5 ×106 tons of CO2 eq.) and 0.54% (5.1 ×1012 Btu), respectively. C Methods for constructing new pipeline connections for an existing, operational pipeline usually result in significant venting of natural gas. In contrast, the “hot tap” pipeline connecting method is a commercially available technology that reduces GHG emissions. This method avoids the need for venting natural gas. It involves attaching a branch pipeline connection on the outside of an operating pipeline and cutting out the inside pipeline wall. Unit Value 109 ton-miles/year 384 109 ton-miles/year

384


2.5 5.1 N/A 13 13 N/A

106 USD ($) % years year-1 $106 /year $106 /year $106 /year $106 /year $106 /year

8.3 10% 15 0.131 9.9 11.0 50.6 N/A 39.6

$/ton CO2 eq.

15.8

a

Net Savings per Unit of Energy Use Reduction (NSER) $/106 BTU 7.8 Net Savings per Unit of Refrigerant Use Reduction $/lb N/A (NSRR) Simple Payback Period (SPP) years 0.2 These assessments are based on the assumptions that these best practices reach their potential maximum market shares in 2025.

(b)

Total methane emission reduction is estimated to be 2.5×106 tons CO2 eq. in 2025.

Calculation:

 21 CO 2 eq. 326,900 miles   8.4 × 103 tons CH ×  × 4   CH 23 , 000 miles 4   = 2.5 × 10 6 Tons CO 2 eq. (c)

The annual GHG emissions reductions are estimated to be 2.5×106

Results:

tons CO2 eq. in 2025.

E.

Estimate of annual energy use reduction: The estimated annual energy use reduction in 2025 is 5.1 ×1012 BTU.

2,000 lbs 21,300 BTU  326,900 miles   8.4 × 103 tons CH 4 × × × = 5.1 × 1012 BTU   ton lb   23,000 miles

F.

Estimate of unit GHG emissions reductions:  2.5 × 10 6 tons CO 2 eq   2,000 lbs  0.013 lb CO 2 eq.      384 × 10 9 ton − miles . ×  ton  = ton − mile    

G.


(

)

 5.1 × 10 6 10 6 BTU  13.2 BTU . =  9  384 × 10 ton − miles  ton − mile

254

H.

Estimate of capital cost i. The capital cost for this practice for a company is estimated to be $36,200, and this practice reduces methane emissions by 0.0244 BcF for this company.122 ii. Methane emission reduction from adopting this practice for the pipeline mode is estimated to be 5.61 BcF in 2025.

  326,900 miles 2,000 lbs ft 3  8.4 × 103 tons CH 4 × × × = 5.61 BcF   23,000 miles ton 0 . 04246 lbs   iii. Total capital costs for adopting this practice in 2025 are estimated to be $8.32 ×106. $36,200 ×

I.

5.61 BcF 0.0244 BcF

= $8.32 × 10 6

Estimate of annual O & M cost i. The annual O & M cost for this practice for a company is estimated to be $43,000, and this practice reduces methane emissions by 0.0244 BcF for this company.122 ii. The annual O & M costs for adopting this practice in 2025 are estimated to be $9.89 ×106.

($43,000) ×

J.

5.61 BcF 0.0244 BcF

= $9.89 × 10 6


1  15  1 ∑  i =1  (1 + 0.1)i  

   

= 0.131


($8.32 × 10

6

)

× 0.131 + $9.89 × 10 6 = $11.0 × 10 6

255

K.

Estimate of energy cost reduction: (a) Assumption: Natural gas price in 2025 is estimated to be $9.95/106 BTU, which is estimated in Appendix E.1.K. (b)

Calculation:


(c) L.

Results:

$9.95 = $50.6 × 10 6 6 10 BTU



$50.6 × 10 6 − $11.0 × 10 6 = $39.6 × 10 6

M.


$39.6 × 10 6 2.5 × 10 6 tons CO 2 eq. N.

=

$15.8 ton CO 2 eq.

Estimate of net savings per unit of energy use reduction: $39.6 × 10 6 $7.8 = 12 6 5.1 × 10 BTU 10 BTU

O.

Estimate of simple payback period: $8.32 × 10 6 ($50.6 × 10 6 − $9.89 × 10 6 ) = 0.20 years

256

Appendix E.4

Best Practice 5-4:

Transfer Compression

This best practice is assessed qualitatively. Table E-4 summarizes the assessment results in the standardized simplified reporting table format. Table E-4. Simplified Summary Table for Best Practice 5-4, Transfer Compression Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Transfer Compression Pipeline Maintenance 70, 71, 72 26, 27, 28 CH4 Technology

Goal is to have all pipeline systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 0.07% and 0.02%, respectively. C During the pipeline maintenance process, a section of pipe is often isolated and taken out for maintenance, and methane is vented from the isolated section. An alternative to venting is to transfer the natural gas in the isolated section to an operating section of the pipeline, thereby avoiding loss of methane. A system for doing this is a transfer compressor unit, which is commercially available. Several transfer compressors can be operated simultaneously to increase the methane recovery rate. 0.07% 0.02% N/A N/A N/A

257

Appendix E.5

Best Practice 5-5:

Inline Inspection

This best practice is assessed qualitatively. Table E-5 summarizes the assessment results in the standardized simplified reporting table format. Table E-5. Simplified Summary Table for Best Practice 5-5, Inline Inspection Attribute Description Practice Name Mode Type Subgroup Responsible Parties Target Parties Target GHGs Strategy Type Practice Goals Developmental Status Practice Summary


Inline Inspection Pipeline Maintenance 70, 71, 72, 73 26, 27, 28 CH4 Technology

Goal is to have all pipeline systems participate. The reductions in modal GHG emissions and energy use in 2025 would be 1.32% and 0.37%, respectively. C Pipeline flaws, especially stress corrosion cracking (SCC), cause pipeline failure that are of safety concern and that lead to fugitive methane emissions. A pipeline inline inspection (ILI) tool, referred to as “smart pig,” was originally designed to inspect internal pipeline conditions, such as dents or metal loss, by using ultrasound. A ultrasound inline inspection tool based on a newer design can detect not only dents or metal loss, but also SCC. This new tool is able to locate more pipeline flaws. By identifying and correcting such flaws sooner, fugitive methane emissions can be reduced. 1.32% 0.37% N/A N/A This upgraded tool can find more flaws in the pipeline system and, therefore, enable quickly corrective action lead to larger reductions in fugitive methane emissions.

258

APPENDIX F.

APPENDIX F.1

FUEL PROPERTIES, CO2 EMISSIONS COEFFICIENTS FOR FULES, AND AVERAGE UNIT FUEL COSTS FOR GUIDEBOOK

Properties of Different Fuels

Many of the GHG emissions from freight transportation sector are related to fuel use, and are influenced by the types of fuels and the properties of fuels. Major fuels used in the freight transportation sector include diesel fuel, jet fuel, residual fuel oil, biodiesel, and natural gas. For these fuels, there are usually a number of parameters that are used to measure chemical and physical properties. These fuel properties impact the performance of vehicle operation and influence the fuel usage and the GHG emissions from freight transportation. For example, the energy density of the fuel will have an affect on the apparent fuel economy.131 This section describes the important parameters for measuring fuel properties, and discusses the fuel properties of diesel fuel, jet fuel, residual fuel oil, biodiesel, and natural gas. F.1.1 Definitions of Fuel Properties The following subsections describe several fuel properties, including specific gravity, cetane number, distillation range, aromatic content, heating value, and viscosity, which influence the performance of vehicle operation and would impact greenhouse gas emissions from the freight transportation. F.1.1.1 Specific Gravity The specific gravity is defined as the ratio of the density of the fuel to the density of water at 60°F.131 F.1.1.2 Cetane Number One key property of diesel fuel is the ease with which it ignites, quantified by the cetane number, with higher numbers indicating greater ignitability. The cetane number is the standard measure of fuel ignition characteristics when injected into a diesel engine. It relates to the delay between when fuel is injected into the cylinder and when ignition occurs. Higher cetane number indicates shorter times between injection of the fuel and its ignition. Good ignition from a high cetane number assists in easy starting, starting at low temperature, low ignition pressures, and smooth operation with lower knocking characteristics.131 Large, slower speed engines, as used in locomotive and marine applications, are more tolerant of poor-quality 259

fuels.146 F.1.1.3 Distillation Range Distillation range refers to the range of boiling points of different liquid fractions of the fuel, which are observed when separating the fuel into its components. The distillation range is generally expressed in terms of the temperatures at which 10 percent (T10), 50 percent (T50), and 90 percent (T90) of the fuel will be evaporated. The highest temperature recorded during distillation is called the end point. However, because a fuel’s end point is difficult to measure with good repeatability, 90 percent distillation point of fuel is commonly used.131 F.1.1.4 Aromatic Content Aromatic content is characterized by the presence of the benzene family in hydrocarbon compounds in the fuel. Aromatic compounds include heavier compounds such as toluene, xylene, and naphthalene.131 F.1.1.5 Heating Value The heating value of a fuel is the enthalpy of reaction for combustion of the fuel. Thus, the heating value is the amount of energy released when the fuel is completely burned in a steady flow process. The magnitude of the heating value depends on the fate of H2O in the combustion products. In most real systems, the H2O leaves the engine or combustor in the vapor phase. For this situation, the Lower Heating Value (LHV) is used. However, in principle, one could condense the water vapor and recover the latent heat of vaporization associated with this phase change. If this could be done, then the total heating value would be the sum of the LHV and the latent heat of condensation, which is referred to as the Higher Heating Value (HHV).131 F.1.1.6 Viscosity Viscosity is a measure of the resistance of a fuel to shear or flow, and is a measure of the fuel's adhesive/cohesive or frictional properties. 131 F.1.2 Diesel Fuel Distillate fuel oil is a classification for one of the distillation fraction of petroleum. It includes diesel fuels and fuel oils. Diesel fuel is a complex mixture of many different hydrocarbons with a distillation range of 350 to 640 °F,131 with carbon numbers in the range of C3 to C25, and with an average molecular weight of about 200.132 Current commercial diesel fuels in the United States include No. 1 diesel fuel, No. 2 diesel fuel, No. 4 diesel fuel, and marine gas oil.111,146 Marine gas oil is one kind of bunker fuel that is used for small and 260

medium sized marine engines.111 No. 1 diesel fuel is usually used in city buses. No. 2 diesel fuel is used in high-speed diesel engines that are operated under load conditions, such as those in trucks and railroad locomotives. No. 4 diesel fuel is usually used in industrial plants and in commercial burner installions, but is also used for low- and medium-speed diesel engines.147 These fuels can differ with respect to cetane number, aromatic content, sulfur level, levels of contaminants (e.g., metals), and viscosity.146 The major fuels related to freight transportation are No. 2 diesel fuel and marine gas oil. Major properties of No. 2 diesel fuel, the fuel used in trucks and locomotives, are listed in Table F-1. The important differences between No. 2 diesel fuels and marine gas oil are sulfur content and viscosity. The sulfur content of marine gas oil is generally about 1.5-2.0% mass, but the sulfur content of No. 2 diesel fuel is generally about 0.05% mass or lower because sulfur content of No. 2 diesel fuel is restricted by state and federal regulations. The maximum viscosity of marine gas oil is about 6.0-11.0 at 104°F, and the density of marine gas oil is about 0.89-0.90 at 60°F.148 Table F-1. Major Properties of No. 2 Diesel Fuel.131,132,149

Composition (weight %)

Distillation range

Property Chemical formula Physical state Molecular weight Carbon Hydrogen Oxygen Specific gravity @ 60˚ F Cetane Number 10% point, °F 50% point, °F 90% point, °F Aromatics, vol% Higher (liquid fuel-liquid water) BTU/lb Lower (liquid fuel-water vapor) BTU/lb

Value

,

Heating value

Higher (liquid fuel-liquid water) BTU/gallon

Latent heat of vaporization

Lower (liquid fuel-water vapor) BTU/gallon @ 60˚F Viscosity, Centipoise @ 60˚F Freezing point, F˚ Reid vapor pressure, psi BTU/lb @ 60˚F BTU/gallon @ 60˚F

261

C3 to C25 Liquid ≈200 84–87 (86.4) 13–16 (13.4) 0 0.81–0.89 (0.84) 40-55 (44) 410 to 430 490 to 520 585 to 620 30 19,200-20,000 18,000-19,000 138,690-138,700 (138,690) 128,400 2.6-4.1 -40–30 0.2 ≈100 ≈700

F.1.3 Jet Fuel Jet fuel is a refined petroleum product used in jet aircraft engines.111 Jet fuel includes kerosene-type jet fuel and naphtha-type jet fuel.150 Kerosene-type jet fuel, including Grades JP-5 and JP-8, is a kerosene-based product that has a distillation temperature of 400 degrees Fahrenheit at the 10-percent recovery point and a final boiling point of 572 degrees Fahrenheit and meeting ASTM Specification D 1655 and Military Specifications MIL-T-5624P and MIL-T-83133D.147 MIL-T-5624P is for JP-5 and MIL-T-83133D is for JP-8.151 Naphtha-type jet fuel, usually being Grade JP-4, is a fuel used primarily for military turbojet and turboprop aircraft engines because it has a lower freeze point than other aviation fuels and meets engine requirements at high altitudes and speeds. It has 20 to 90 percent distillation temperatures of 290 degrees to 470 degrees Fahrenheit, and meeting Military Specification MIL-T-5624L. It is 147,151 From a chemistry standpoint, the composition of jet fuels is quite similar to that of diesel fuel, kerosene or light distillates including home heating oil. Jet fuels are relatively safe to transport, store and handle when compared with gasoline. All of these jet fuels have about the similar heating values (around 18,400 BTU/lb), but JP-4 is more flammable than JP-8 and both JP-4 and JP-8 are more flammable than JP-5. The Navy uses JP-5 since shipboard use requires a greater degree of safety. JP-8+100 is a new product that contains an additive package designed to increases the temperature range over which the fuels remains thermally stable by 100 °F. While commercial aircraft still use JP-4, the Navy now uses JP-5, and the Air Force uses JP-8+100. 152 Major properties of jet fuel are listed in Table F-2. Table F-2. Major Properties of Jet Fuel151,153 Property Carbon Composition Hydrogen (weight %) Oxygen Density (kg/L) @ 15˚C Cetane Number 10% point, °C 20% point, °C Distillation 50% point, °C range 90% point, °C End point, °C Aromatics, vol% Lower (liquid fuel-water Heating value* vapor) BTU/lb Viscosity, Centipoise @ 20˚C Freezing point, F˚ Vapor pressure (psi) @ 100˚F

JP-4 13.5 0.751-0.802 145 190 245 270 25.0

JP-5 13.4 0.788-0.845 205 300 25.0

JP-8 13.4 0.775-0.840

18,400 -72 2.0-3.0

18,300 8.5 -61 -

18,400 8.0 -53 -

262

205 300 25.0

F.1.4 Biodiesel Biodiesel is defined as the mono alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats, and was developed for use in compression-ignition engines.154 Major properties of 100% soybean-based biodiesel are listed in Table F-3. Table F-3. Major Properties of B100 Biodiesel Blend Stock.131,154 Property Chemical formula Physical state Composition (weight %)

Value

Carbon Hydrogen Oxygen

Specific gravity @ 60˚F Cetane Number 10% point, °F 50% point, °F 90% point, °F Aromatics, vol% Higher (liquid fuel-liquid water) BTU/lb Higher (liquid fuel-liquid water) Heating value* BTU/gallon Lower (liquid fuel-water vapor) BTU/lb Viscosity, Centipoise @ 104˚F Boiling temperature, F˚

Distillation range

C12 to C22 Liquid 76.9-77.3 11.8-12.1 11.0 0.886 - 0.89 (average 0.888) 47.5 631.4 636.8 645.8 0 17,111 126,789 15,993 4.1 573

* Higher heating value of biodiesel is about 17,111 BTU/lb, or 126,789 BTU/gallon. 17,111

BTU lb 888 g 3.785 L 126,789 BTU × × × = lb 453.6 g L gallon gallon

F.1.5 Residual Fuel Oil Residual fuel oil is a general classification for the heavier oils that remain after the distillate fractions are distilled away in refinery operations. It includes No. 5 and No. 6 fuel oils and is used for large steam boilers and, with fuel preheating, for very large compression ignition engines, such as ocean-going ships.111,147 No. 5 fuel oil is a residual fuel oil of medium viscosity, and is used in steam-powered vessels in government service and inshore power plants. No. 6 fuel oil includes marine residual fuel oil, another kind of bunker fuel (called Bunker C fuel oil), and is used for electric power plants, space heaters, marine vessels, and various industrial purposes.147 Major properties of marine residual fuel oil are listed in Table F-4. 263

Table F-4. Major Properties of Marine Residual Fuel Oil.147,148,155 Property Specific gravity @ 60˚F Sulfur content, % mass Higher heating value, BTU/gallon Higher heating value, BTU/lb Viscosity, Centipoise @ 122˚F Flash point, F˚

Value 0.991 5 149,700 19,011 340 140

F.1.6 Natural Gas Natural gas is a naturally occurring mixture of hydrocarbon and non-hydrocarbon gases found in porous geologic formations beneath the earth's surface, often in association with petroleum. Natural gas is a fossil fuel composed almost entirely of methane, but does contain small amounts of other gases, such as ethane, propane, butane and pentane.156 Major properties of natural gas are listed in Table F-5.157 Table F-5. Major Properties of Natural Gas.132,145,156,157 Property Methane concentration, % Volume

Value 80 - 99

Ethane concentration, % Volume

2.7 - 4.6

Nitrogen concentration, % Volume

0.1 - 15

Carbon dioxide concentration, % Volume]

1-5

Sulphur concentration, ppm, mass Physical state Average Molecular weight Carbon Composition Hydrogen (weight %) Oxygen Specific gravity @ 59 ˚F (15 ˚F) Lower heating value, MJ/kg Heating value

Lower heating value, BTU/lb Lower heating value, BTU/ft3 Freezing point, F˚ Reid vapor pressure, psi

APPENDIX F.2