the Broad Street houses. We determined this by conducting multiple cost-benefit analyses comparing the possible economic costs of installation with the ...
A Feasibility Study of Geothermal Heating and Cooling at Colgate University Trevor Halfhide, Seghan MacDonald, Josh McLane, and Sarah Titcomb
December, 11 2009
Department of Environmental Studies Colgate University 13 Oak Drive Hamilton, NY 13346 0
Contents: Project Overview: ............................................................................................................... 2 Introduction to Geothermal Energy: ................................................................................... 2 Types of Geothermal Energy:............................................................................................. 4 Shallow ........................................................................................................................... 4 Deep ................................................................................................................................ 7 History of Geothermal Use: .............................................................................................. 10 Feasibility of Geothermal Energy at Colgate: .................................................................. 12 Costs.............................................................................................................................. 13 Electricity...................................................................................................................... 20 Geology......................................................................................................................... 21 Valuation of Benefits .................................................................................................... 27 A Condensed List of the Potential Benefits of Geothermal at Colgate: ....................... 30 Hamilton College Comparison ..................................................................................... 32 Potential Funding .......................................................................................................... 33 Potential Obstacles........................................................................................................ 35 A Condensed List of the Potential Barriers of Geothermal at Colgate:........................ 36 Conclusions:...................................................................................................................... 37 Acknowledgements........................................................................................................... 38 Appendix I: ....................................................................................................................... 39 Appendix II: ...................................................................................................................... 40 Appendix III: (to be added) .............................................................................................. 45
1
Project Overview: The goal of this paper is to explore the feasibility of geothermal technologies on Colgate’s campus. This document is by no means an all encompassing study, but serves as a preliminary step forming the foundations for future research.
We ultimately
conclude that geothermal heating and cooling is a very feasible option for Colgate and that vertical, closed-loop shallow systems have the most potential. This is the best geothermal option for Colgate because of the restrictions associated with the underlying geology and the concerns held by the Village of Hamilton about drinking water contamination. We recommend that the first installations of these shallow systems be in the Broad Street houses.
We determined this by conducting multiple cost-benefit
analyses comparing the possible economic costs of installation with the potential economic, social, and environmental benefits.
The sections that follow explain the
science behind various forms of geothermal energy and more specifically detail how and why we reached the conclusion that geothermal energy is feasible for Colgate.
Introduction to Geothermal Energy: In its most basic form, geothermal energy originates in the earth and flows naturally up into the atmosphere through volcanoes, hot springs, and geysers. 1 Most naturally occurring sources of geothermal energy in the United States are located on the
1
Geothermal Energy. (2009). In Encyclopedia Britannica. Retrieved from http://search.eb.com/eb/article9036528
2
West Coast because of the amount of plate tectonic activity that forces energy up. 2 However, geothermal energy can also be extracted manually by humans through shallow or deep well systems. Humans can harness this energy and generate electricity through the creation of power plants, or use it simply to heat and cool individual residential or commercial buildings. Electricity generation, heating, and cooling can be accomplished with geothermal technologies because of the temperature differential between the earth and the air above the surface. At great depths, the earth is warmer because of the heat energy constantly being created within the core and the radioactive decay of particles in the crust. 3 Closer to the surface, the earth remains a constant temperature because the ground provides insulation from the air above. One of the biggest selling points for geothermal energy is the fact that it is a renewable, clean, domestic, and dependable source of energy. As climate change places environmental pressures on countries across the world, and reliance on foreign oil creates political and economic pressures on the United States and others, geothermal is becoming a more attractive energy alternative. Geothermal energy does not rely on variable inputs such as wind or sun as do many other renewable options. A geothermal system just needs access to the earth's natural temperature differential and can then produce electricity, heating, or cooling 24 hours a day, 7 days a week. Furthermore, as the price of non-renewable energy sources such as oil and natural gas rise, geothermal energy offers a great alternative for the U.S and Colgate, potentially alongside other more renewable sources such as woodchips. The current technologies available to harness this 2
Blackwell, D. D., and Richards, M. 2004. Geothermal Map of North America. American Assoc. Petroleum Geologist (AAPG), 1 sheet, scale 1:6,500,000. 3 MIT-led Interdisciplinary Panel. (2006). The Future of Geothermal Energy: Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century. Cambridge, MA.: Tester, Jefferson et al., section 2.2.6
3
temperature differential can be broken down into the two broad categories of deep and shallow geothermal systems. 4
Types of Geothermal Energy: Shallow Within the broad label of shallow geothermal systems there are four main types of geoexchange systems: closed-loop horizontal, closed-loop vertical, closed-loop pond or lake, and open-loop. Closed-loop systems consist of a network of pipes that cycle water or a refrigerant through a closed system where nothing leaves or enters the system except heat. The pipes can run horizontally about ten feet below the surface, vertically a few hundred feet into the earth, or through/under a large body of water. Figures 1 through 3 depict these systems. The selection of the different types of systems (horizontal, vertical, or pond) depends on the availability of resources such as capital, space, water, temperatures, and bedrock type.
Open-loop systems alternatively draw water from
shallow aquifers into an open-loop pipe system to extract its heat energy in a similar fashion as closed-loop systems. Water is drawn up from wells at one end of the system and returned back into the aquifer at the other.5 Geoexchange systems, also known as Geothermal Heat Pumps (GHPs), utilize shallow thermal energy from the uppermost layer of the earth's crust. About ten feet below the surface, the earth maintains a constant temperature between about 50 and 60 4
U.S. Department of Energy (2008, September). Geothermal Basics. http://www1.eere.energy.gov/geothermal/geothermal_basics.html 5 U.S. Department of Energy (2008, December). Benefits of Geothermal Heat Pump Systems. Retrieved from http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/mytopic=12660
4
degrees Fahrenheit year-round. 6 GHPs use this constant temperature to heat buildings in the winter and cool them in the summer. The fluid, which is water for open-loop systems and a refrigerant such as glycol for closed-loop systems, passes through the pipes and is heated or cooled by the earth’s constant temperature. As this fluid moves through the pipes inside the building, it is compressed within a heat pump to further increase or decrease its temperature depending on the time of year.
The temperature is then
exchanged directly or indirectly to a water or air medium through a heat exchanger for distribution throughout the building. Much of the temperature gained from compression is used to heat or cool the building, and the water or refrigerant is re-injected into the wells at only a slightly different temperature than the ground. 7 These shallow systems are usually set up on a building by building basis because they do not have the capabilities of deep systems to generate enough heating or cooling to run a central plant.
Figure 1: An image of a horizontal closed-loop geoexchange system. A horizontal loop needs a lot of square footage to be able to meet 100% of the heating and cooling needs of the building. 8
6
U.S. Department of Energy, Geothermal Basics Darby, Peter (personal communication, 9-28-09; 10-1-09); Geothermal Heat Pump Consortium. (2007). Information for Evaluating Geoexchange Applications (2nd ed). Washington, D.C. 8 Geothermal Heat Pump Consortium, Information for Evaluating Geoexchange Applications 7
5
Figure 2: An image of a vertical closed-loop geoexchange system. A vertical system needs less square footage but must go down at least 300 feet into the ground. 9
Figure 3: An image of a pond/lake closed-loop geoexchange system. Such a system requires a large enough pond or lake that has a near constant temperature year round. 10
GHPs require a large initial financial investment, but generally have very low operation and maintenance costs. Over time, these low costs will generally make GHPs more cost effective than traditional electric, fuel, or natural gas heating systems. But the cost and source of electricity inputs must be analyzed because GHPs can sometimes increase electricity consumption due to their need to pump and compress water. 11 While it is not applicable to Colgate, replacing electric heating and air conditioning systems with geothermal heating systems can actually decrease annual electricity costs. In a case
9
Ibid Ibid 11 Darby, Peter (personal communication, 9-28-09; 10-1-09) 10
6
study of the Myers family, residents of the Village of Hamilton, geothermal contractor Peter Darby found that replacing electric base heating systems would cut their electric consumption by nearly one third. 12 The timescale over which GHPs are able to become cost effective thus depends on various factors such as the type of GHP system, the fluctuating cost and consumption of electricity and fossil fuels, and the already existing heating and cooling systems. The cost of installing geothermal systems also depends on whether the building in question is being retrofitted with geothermal technology or if geothermal technology is worked into the plans for a new construction project. Retrofitting is generally more expensive, depending on the existing infrastructure, because of the cost of replacing an existing functioning heating system. When constructing a new building, the relative cost of installing a geothermal system is considerably less because only the differential cost between a geothermal system and a traditional heating system must be accounted for. Therefore the main differential between installing a geothermal system and installing a more traditional heating system is the cost associated with drilling wells. 13
Deep Deep geothermal energy can be broken down into two separate categories, power plants and direct-use systems. Geothermal power plants generate electricity by using thermal energy from sources such as geysers, hot springs, or deep and extremely hot aquifers to drive turbines. Dry steam, flash steam, and binary cycle power plants are the
12 13
Ibid Ibid
7
three types of power plants that can be constructed (see Figures 4, 5, and 6). 14 Electricity generated from geothermal power plants is an entirely renewable and reliable form of energy, but its application depends completely on the geology of the site. Therefore the greatest potential for these systems is located on the west coast of the U.S, where these thermal resources are more commonly found due to high thermal gradients that allow heat to flow or be extracted more easily to the surface. 15 These high thermal gradients are found in only approximately 10 percent of the world’s land area and require plate tectonic activity. 16
Figure 4: A dry steam power plants use the steam drawn from the earth to drive a turbine. This was the original type of geothermal power plant. 17
14
U.S. Department of Energy (2008, September). Hydrothermal Power Systems. http://www1.eere.energy.gov/geothermal/powerplants.html 15 Blackwell, D. D., and Richards, M., Geothermal Map of North America 16 László, E. (1981). Geothermal Energy: An Old Ally. Ambio, 10(5), 248-249. 17 U.S. Department of Energy, Hydrothermal Power Systems
8
Figure 5: A flash steam power plant sprays fluid into deep wells which is quickly transformed into hot steam because of the extreme heat of the wells. This “flash” of steam drives a turbine. 18
Figure 6: A binary cycle power plant uses a heat exchanger to transfer the ground heat to a secondary fluid that has a lower boiling point than water. The fluid creates steam that drives the turbine, condenses, and then cycles back through a closed loop. This is similar to the shallow closed-loop systems, but on a much grander scale. 19
Direct-use hot water systems are another form of deep geothermal energy generation but one where the technology is relatively young and still in the experimental stages. Direct-use hot water systems take advantage of the earth’s high temperatures at great depths just as other deep systems. Water pumped from these depths is used in various heating and energy applications. The usable temperature ranges between about
18 19
Ibid Ibid
9
68° and 302°F. 20
Generally the system consists of a deep well with a pump and an
injection system for drawing and disposing of water. The depth of this well and therefore the feasibility of these systems depends on the geology of the area. They are ideal where geothermal "hot spots" are present, as wells can be shallower and constructed at lower costs. 21
Direct-use hot water systems allow for other practical applications such as
heating sidewalks and roads to melt the ice or heating floors of buildings which would allow heat to radiate up through the rest of the building because the amount of thermal energy available to these systems is greater than the amount available to shallow systems.
History of Geothermal Use: While European settler John Colter was the first to capture geothermal energy in 1807 with the geysers around Yellowstone, geothermal power generation was not developed until 1904 in Italy. 22 As of around the turn of the century, twenty countries around the world use geothermal energy to generate a cumulative 8,000 megawatts of electricity
23
The United States and the Philippines together account for about half of the
world’s generation of geothermal energy. 24 Geothermal technologies have also become popular among colleges and universities across the country as they begin efforts to become more sustainable and carbon neutral. 20
National Renewable Energy Laboratory (1998). Direct Use of Geothermal Energy. Washington, D.C.: Author. 21 U.S. Department of Energy (2008, March). Direct Use of Geothermal Energy. Retrieved from http://www1.eere.energy.gov/geothermal/directuse.html 22 U.S. Department of Energy (2008, November). A History of Geothermal Energy in the United States. http://www1.eere.energy.gov/geothermal/history.html; Tolme, Paul (2008, September) Universities Lead the Charge to Mine the Heat Beneath our Feet. Retrieved from http://www.nwf.org/campusEcology/climateedu/geothermal.cfm 23 Brown, Lester (2003). Plan B: Rescuing a Planet under Stress and a Civilization in Trouble. New York: W.W. Norton & Co. 24 Ibid
10
The Oregon Institute of Technology recently spent $6.5 million to build the first geoplant on a college campus. The plant will generate 100% of the school’s electricity and help make the campus more self sufficient. Oregon has the advantage of being on the West Coast and thus having access to 300 degree water 6,000 feet below the surface, making the construction of a deep well power plant possible. Such an endeavor would not be possible on Colgate’s campus, but the venture still presents a noteworthy example of a progressive initiative by a university. 25 Initiatives that aim to make Colgate more self sufficient in heating will be important steps in making the campus more carbon neutral and more sustainable. Hamilton College provides a much more attainable example of a college on the East Coast that is using geothermal energy to the best of their abilities. Hamilton already has geothermal heating and cooling capabilities in three buildings including the science center and a large dorm and is in the process of installing a system in the Student Union. Other East Coast and Southern schools are also testing the feasibility of relying at least partially on geothermal energy. Bard College, another school in New York State, has begun making engineering reports for geothermal energy on their campus on a building by building basis. 26 Southern Methodist University in Texas has begun a project to map the "location and depth of available heat" throughout the nation by analyzing data from deep wells already dug by oil and gas companies. 27
25
Priebe, Maryruth (2009, September) Hot and Steamy: Ground-Source on Campus. Retrieved from http://www.nwf.org/campusEcology/climateedu/articleView.cfm?iArticleID=102 26 New York State Energy Research and Development Authority (2009). Energy Efficiency Measures at New College Dorm Complex. Retrieved from http://www.nyserda.org/Programs/New_Construction/Case_Studies/bardcollege.pdf 27 Tolme, Paul, Universities Lead the Charge to Mine the Heat Beneath our Feet
11
Such mapping is very prevalent on the West Coast, but little is known about geothermal resources in the Midwest, East, and South. Colgate might consider taking part in similar geothermal mapping studies for the New York region in order to create a more precise feasibility report in terms of temperature gradients.
This could be
accomplished by an outside party or guided by a geology seminar or lab, and mapped with the aid of the university’s GIS course. While the cost of digging the wells necessary for such a study is substantial, collaboration with other institutions would yield very helpful information that would aid in discovering the feasibility of geothermal systems for specific sites. However, at the local scale, we suggest that a completely comprehensive study that maps the Village of Hamilton is not necessary. This paper identifies six locations that should be considered for geothermal heating and cooling, digging an exploratory well in one of these yards of one of these houses would allow the temperature gradient to be discovered and could also be used later in the actual GHP system (See Table 1 for information on the recommended locations).
Feasibility of Geothermal Energy at Colgate: The goal of this section is to outline the current geothermal technologies available for institutional use at Colgate in terms of the costs and benefits.
Ultimately, we
conclude that geothermal heating and cooling at Colgate is most feasible in auxiliary buildings off of the central line, and the greatest potential lies in the university-owned houses on Broad Street. These buildings have the most potential because of the existing fuel sources used and the potential for future renovations. While the initial costs of 12
installing geothermal systems may be higher than the costs of installing traditional heating systems, all of these buildings will become cost effective in a maximum of twenty to forty years. Not only will the systems be cost effective, but also they will yield social and environmental benefits. Transitioning to geothermal heating and cooling will help make these buildings on Broad Street, currently running on fuel oil #2, more carbon friendly, contribute to potential LEED certifications, and lower the school’s overall carbon footprint. The geology of Colgate also allows geothermal energy to be realistic in these auxiliary buildings on Broad Street because of their location over soft sandstone and a confined aquifer. Finally, the success of geothermal technology at Hamilton College shows that this technology is very feasible for Colgate.
Costs There are high initial costs associated with installing geothermal heating and cooling systems. These include the well digging, the materials and the construction costs of installing pipes and the other necessary mechanical units, and the purchase of heat pumps. Based on data obtained from Hamilton College, each well costs about $5,313 to dig and the mechanical system (labor, piping, glycol, etc.) costs are around $29,875 per well. 28 A building requires about 1 well for every 1,300 square feet of building space. The heat pumps themselves cost about $2,500 per ton of capacity on average. 29 In the Village of Hamilton’s climate, about 1 ton of geothermal heating/cooling capacity is needed per 500 square feet of building. 30
These averages were used to calculate the
specific costs for the individual buildings represented in the figures below. (See 28
Bellona, Steve(personal communication, 10-23-09) California Energy Commission (2006). Geothermal or Ground Source Heat Pumps. Retrieved from http://www.consumerenergycenter.org/home/heating_cooling/geothermal.html 30 Darby, Peter, personal communication 29
13
Appendix I, Table 2 for the raw data used in calculations). Many of the costs stated above are estimated because the exact costs cannot be determined prior to the completion of engineering reports for specific buildings as there are so many different variables involved. While the initial cost may be higher compared to other systems with similar capacities, geothermal systems have much lower operational and maintenance costs. One ongoing cost that must be accounted for is the electricity the geothermal heat pumps require to compress and distribute the liquid through the pipes. Despite our estimation of high costs at Colgate, Hamilton College and other universities have found that the costs of implementing a geothermal system are usually recovered on average in six to ten years, depending on the price of fossil fuels and the size of the initial investment. 31 While our estimates suggest about a thirty year payback time for most buildings, these calculations do not include the social and environmental benefits of installation and assume the buildings are being retrofitted; thus the estimated payback time may be too long. The social and environmental benefits, detailed below in the section entitled “Valuation of Benefits,” are qualitative in nature and thus we were unable to include them in quantitative calculations of costs. New construction also often offers the most cost effective implementation of geothermal technology as the forgone cost of installing a typical boiler system offsets much of the cost of the geothermal heat pumps and the required pumping. The following figures give a building by building cost analysis for retrofitting Colgate's buildings currently running on fuel oil #2 with geothermal heating and cooling systems. Cost estimates for the geothermal systems are likely overestimates, for the reasons previously stated, and will need to be corrected after more information is 31
Bellona, Steve, personal communication
14
gathered. Buildings currently heated from the central line were not considered for geothermal in this project because it is currently more cost effective for them to stay connected to the line. This also makes sense for the university’s environmental impact because the central heating plant is a carbon neutral source of heat when it burns woodchips. Figure 7 shows the costs associated with geothermal energy for every building owned by Colgate that currently uses fuel oil #2 for heating. This figure helps select the buildings to consider more seriously for geothermal technologies because it clearly displays the buildings where the cost of transitioning to geothermal will and will not be recovered in the short term. The payback timescales for geothermal systems are represented in Figures 8 through 12 for the buildings with the most potential. Geologic data, as described below in the “Geology” section, further helped to select buildings that we ultimately chose to be recommend (See Table 1 for recommendations). The geology “up the hill” under the academic buildings and firstyear dorms is not the most conducive for geothermal because of the presence of limestone bedrock and an unconfined aquifer. As a result, we did not seriously consider geothermal alternatives for buildings “up the hill.”
15
A Comparison of Traditional vs. Geothermal Heating and Cooling Costs per Fuel Oil #2 Building 2500000.00
Cost (dollars)
2000000.00 1500000.00 1000000.00
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Watson House
Sigma Chi
Seven Oaks Maint Bldg
Sanford Field House
Preston Hill Apartments
88 Hamilton
102 Broad
Cultural Center
Conant House
Chapel House
94 Broad
French / Italian House
Status Quo Geothermal Year 1 Geothermal Year 2
80 Broad
70 Broad
49 Broad
0.00
118 Broad
500000.00
Buildings
Figure 7: Displays the total costs for all buildings currently heated by fuel oil #2 if the current heating system were to remain (status quo) or if geothermal heating and cooling were to be installed. The geothermal prices are broken down into the initial costs (well digging, heating units, and mechanical systems) and the second year costs (just electricity).29
16
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Seven Oaks Maint Bldg
Preston Hill Apartments
88 Hamilton
102 Broad
118 Broad
94 Broad
80 Broad
70 Broad
800000 700000 600000 500000 400000 300000 200000 100000 0 49 Broad
Cost (dollars)
A Comparison of the Total Expenditures in Ten Years for the Current Fuel Oil #2 Heating System vs. Geothermal Heating and Cooling
Geothermal 10 Years Status Quo 10 Years
Buildings
Figure 8: Selected buildings that are not up the hill and have the most potential for becoming cost effective. At the ten year mark not one building is cost effective with geothermal heating and cooling. 32 A Comparison of the Total Expenditures in Twenty Years for the Current Fuel Oil # 2 Heating System vs. Geothermal Heating and Cooling
Buildings
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Preston Hill Apartments
88 Hamilton
102 Broad
118 Broad
94 Broad
80 Broad
70 Broad
200000 100000 0
Seven Oaks Maint Bldg
600000 500000 400000 300000
49 Broad
Cost (dollars)
800000 700000
Geothermal 20 Years Status Quo 20 Years
Figure 9: Selected buildings that are not up the hill and have the most potential for becoming cost effective. At the twenty year mark 88 Hamilton and 13 East Kendrick will become cost effective. 33
32
Colgate University, Buildings and Grounds (2009) [Campus Energy Consumption Data by Building]. Unpublished Raw Data. These calculations assume that the inflation rate of fuel prices is the same as the appropriate discount rate, and that annual maintenance costs of geothermal systems equal the nonmonetary benefits. These issues are explored further in an appendix (to be added soon). 33 Ibid 17
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Seven Oaks Maint Bldg
Preston Hill Apartments
88 Hamilton
102 Broad
118 Broad
94 Broad
80 Broad
70 Broad
900000 800000 700000 600000 500000 400000 300000 200000 100000 0 49 Broad
Cost (dollars)
A Comparison of the Total Expenditures in Thirty Years for the Current Fuel Oil #2 Heating System vs. Geothermal Heating and Cooling
Geothermal 30 Years Status Quo 30 Years
Buildings
Figure 10: Selected buildings that are not up the hill and have the most potential for becoming cost effective. At the thirty year mark almost half of the buildings will have become cost effective. 34 A Comparison of the Total Expenditures in Fourty Years for the Current Fuel Oil #2 Heating System vs. Geothermal Heating and Cooling 1200000 Cost (dollars)
1000000 800000 600000 400000
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Preston Hill Apartments
88 Hamilton
102 Broad
118 Broad
94 Broad
80 Broad
70 Broad
49 Broad
0
Seven Oaks Maint Bldg
200000
Geothermal 40 Years Status Quo 40 Years
Buildings
Figure 11: Selected buildings that are not up the hill and have the most potential for becoming cost effective. At the forty year mark almost all of the buildings will have become cost effective. 35
34 35
Ibid Ibid
18
13 East Kendrick
68 Broad
92 Broad
59 Hamilton
102 Broad
79 Hamilton
84 Broad
Seven Oaks Club House
116 Broad
Seven Oaks Maint Bldg
Preston Hill Apartments
88 Hamilton
102 Broad
118 Broad
94 Broad
80 Broad
70 Broad
1600000 1400000 1200000 1000000 800000 600000 400000 200000 0 49 Broad
Cost (dollars)
A Comparison of the Total Expenditures in Fifty Years for the Current Fuel Oil #2 Heating System vs. Geothermal Heating and Cooling
Geothermal 50 Years Status Quo 50 Years
Buildings
Figure 12: Selected buildings that are not up the hill and have the most potential for becoming cost effective. At the fifty year mark every building except the Seven Oaks Club House, 59 Hamilton, and 68 Broad will be cost effective with geothermal heating and cooling. 36
Based on the figures above and prior research, we recommend that Colgate focus its energies on implementing GHP technologies first in houses on Broad Street running on fuel oil #2 (see Table 1). If these projects prove successful and geothermal technology has been established at Colgate along Broad Street, the potential for adapting the technology to buildings on the central line could be assessed. We recommend initially assessing Broad Street for a number of economic, environmental, and geologic reasons. At this time, there is no convincing economic or environmental arguments to completely ignore the central heating plant as woodchips and fuel oil #6 are inexpensive, and burning woodchips is technically carbon neutral. Our recommendations also stem from the idea that the power plant may be expanded soon to allow for a greater use of woodchips or natural gas. Appendix II illustrates how geothermal technology can be evaluated in the context of new construction projects. 36
Ibid
19
All Buildings Heated by Fuel Oil #2 49 Broad 68 Broad 70 Broad 80 Broad 84 Broad 92 Broad 94 Broad 102 Broad 116 Broad 118 Broad Chapel House Conant House Cultural Center French / Italian House Preston Hill Apartments Sanford Field House Seven Oaks Maint Bldg Seven Oaks Club House Sigma Chi Watson House 59 Hamilton 79 Hamilton 88 Hamilton 13 East Kendrick
Buildings with the Most Potential to Be Cost Effective* 49 Broad 68 Broad 70 Broad 80 Broad 84 Broad 92 Broad 94 Broad 102 Broad 116 Broad 118 Broad Preston Hill Apartments Seven Oaks Maint Bldg Seven Oaks Club House 59 Hamilton 79 Hamilton 88 Hamilton 13 East Kendrick
Buildings Cost Effective with Geothermal by 30 Years 49 Broad 80 Broad 92 Broad 94 Broad 116 Broad 118 Broad Preston Hill Apartments 88 Hamilton 13 East Kendrick
Buildings Recommended for the First Round of Geothermal Installations 49 Broad 80 Broad 92 Broad 94 Broad 116 Broad 118 Broad
Table 1: A list of all the buildings on Colgate’s campus heated with Fuel Oil #2 and our final recommendations for a focus on Broad Street (specifically the houses above) for a first round of geothermal installations. The * indicates that this decision was based on the results in Figure 7
Electricity Electricity is the biggest unknown factor in this project. Future research must be conducted on this topic to discover the true costs of geoexchange technology. In the above figures the electricity costs for geothermal are considered the same as the current electricity costs, but this is not necessarily the case as the current electricity consumption is mainly for lighting and power rather than heating purposes. Geoexchange systems could potentially increase the electricity consumption of Colgate as the heat pumps require electricity for the movement and compression of liquids within pipes. We cannot determine the exact amount of electricity required for such actions and thus the exact 20
costs associated with electricity are unknown. Testing and the first installation of a geoexchange heating and cooling system on campus will help bring to light the true costs and benefits.
Geology As previously explained, deep geothermal energy and the creation of power plants is very dependent on location.
Deep geothermal wells typically harness energy at
geothermal “hot spots,” along plate boundaries where there are large amounts of tectonic activity. 37 Hamilton, NY is not located near any “hot spots” and it is therefore not feasible to pursue deep geothermal energy on campus. Instead efforts should be put toward the development of shallow GHPs. These geoexchange systems require wells to be dug at depths ranging from 10 to 500 feet depending on the type of system and the local geology. Factors such as depth of bedrock, depth of aquifers, and temperature gradient all play a role in the required depth of the well and the cost of digging. As knowledge of these factors, especially temperature gradients, is limited in our area, the cost structure of GHP construction is subject to variation.
37
U.S. Department of Energy, Direct Use of Geothermal Energy
21
Figure 13: An aerial photo of the Colgate campus with buildings highlighted to show whether they are heated by the central heating plant or by fuel oil #2. The buildings in blue are not connected to the central heating line and thus hold more potential for geothermal. 38
There are two main types of bedrock located under Colgate’s buildings. As seen in Figure 14, the majority of buildings connected to the central heating plant are on top of limestone and those buildings currently running on fuel oil #2 are over sandstone. This geologic information allows geothermal heating and cooling to be further feasible for the Broad Street houses recommended in Table 1 because sandstone is soft and much easier to drill through than limestone. General data also points to the idea that bedrock is deeper in the center of the valley because it sits below a thick layer of glacial till. Bedrock could possibly be as deep as a hundred feet or more in some parts of the valley. 39 Exploratory wells or participation in geological surveys, like those conducted by Southern Methodist University, would provide the information required for accurate 38
Colgate Campus Buildings by Heat Source. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] 39 Selleck, Bruce, personal communication
22
analysis. Despite the lack of any wells on Colgate's campus to confirm the statements made above about bedrock, we advocate for a shallow closed-loop vertical system.
Figure 14: The same geographic location as Figure 13; this map highlights the USGS bedrock under the buildings connected and not connected to the central line. The bedrock will affect the costs of geothermal because the harder the rock, the more costly the drilling will be. Sandstone is soft and would be easy to drill through making geothermal practical for most of the buildings not attached to the central line.40
Having an aquifer directly below many of the buildings heated by fuel oil #2 gives Colgate the opportunity to use open-loop geothermal systems.
However, the
Village of Hamilton has very strict regulations over any actions that require drilling into the aquifer because such actions could contaminate the drinking water supply. 41
A
closed-loop system has less risk of contaminating aquifers and groundwater because everything is contained within pipes. The system is also less likely to develop a blockage in the pipes. This is a complication that can result in an open-loop system from pumping
40
Types of Bedrock Under Colgate Campus Buildings. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] 41 Graham, Sean (personal communication, 12-4-09)
23
water into the pipes from the aquifer that could ultimately disrupt the functional ability of the system. 42 According to the USGS map in Figure 15, the Village of Hamilton may also have a confined aquifer below the buildings heated by fuel oil #2, creating further incentives for focusing efforts on these buildings. By definition, the aquifer is below the bedrock, which may mean that it is not regulated by the Village of Hamilton.
Figure 15: The same map of the Colgate buildings as shown in Figures 13 and 14, but this time highlighting the USGS map of aquifers under Colgate. Aquifer locations will affect the costs of geothermal because of both the ease of drilling and Hamilton’s regulations. 43
Another factor that contributed to our support of a vertical closed-loop system is that it requires less surface area near the building. There is limited space in the backyards of houses along Broad Street and even less space “up the hill” for academic buildings and first year dorms, making a horizontal closed-loop system out the question. A horizontal system requires an area of at least 300 feet long with a width that depends on the number 42
Bellona, Steve, personal communication Aquifers Under Colgate Campus Buildings. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software]
43
24
of trenches required. A horizontal system would take up more space than Colgate has, while a vertical system would cover a much smaller plot of land. Vertical wells require a maximum of 20 feet between wells. 44 The depth and number of wells required depend on the amount of energy needed for each building. 45 The depth the pipes reach cannot be more than 500 feet as defined by the Village of Hamilton regulations. 46 However, this is not an issue as wells deeper than 500 feet can lead to system complications. 47 Figure 16 shows that the houses along Broad Street have ample room for a vertical closed-loop system and highlights 92 and 94 Broad in particular. 92 Broad Street would need approximately 240 square feet for a vertical closed-loop system and 94 Broad Street will need approximately 200 square feet for a vertical closed-loop system, both of which can be provided in the buildings’ respective backyards. A closed-loop pond/lake system is not an option for Broad Street houses because Taylor Lake is not large enough or deep enough to provide constant temperatures.
44
Bellona, Steve, personal communication Ibid 46 Graham, Sean, personal communication 47 Bellona, Steve, personal communication 45
25
Figure 16: An aerial photo of some of the houses on Broad Street to show that the backyards of these houses do have enough space for a vertical geoexchange system. The backyards’ of 92 and 94 Broad Street are highlighted to give an example of the ample dimensions. 48
Figures 13 through 16 display the complete feasibility of geoexchange heating and cooling for the buildings not on the central line in terms of geology. The majority of the buildings most economically feasible for geothermal are located on top of soft sandstone that will be easy to drill through, are above a confined aquifer that may allow the Village to be less concerned with water contamination, and have backyards large enough to install a vertical closed-loop system. The temperature gradients located under the fuel oil #2 buildings is unknown, so an exploratory well must be dug to decide the depth required for the well system. If results from the exploratory well were favorable, the well could be used as part of the geoexchange system.
48
Backyards of Broad Street Houses. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software]
26
Valuation of Benefits A major deterrent for implementing geothermal technology is the high investment cost and the long timeline for payback. However, the cost-benefit analyses represented in Figures 7 through 12 underestimate the actual benefits. As many of the main benefits are qualitative and many of the costs are quantitative, the costs of geothermal energy are abundantly clear while the benefits are more uncertain and long-term. We stress that these benefits associated with geothermal technology should be considered in the decision making process. Considering the social and environmental qualitative benefits as well as the financial benefits will allow for a shorter payback time and greater cost effectiveness. There are many methods of valuing qualitative values, though none are without fault. Valuation systems based on surveys that attempt to quantify total willingness to pay for reduction of carbon emissions or total willingness to accept the consequences if no reduction occurs can be used in this case. One example is a contingent valuation survey that asks respondents to place a value on cutting increased carbon emissions to preserve the environment in its current state. We recommend that if quantitative benefits are required, such surveys be administered on campus. Financial costs aside, geothermal technology is appealing for a number of reasons. A major factor is its contribution to abatement of carbon dioxide emissions. 49 Reducing carbon emissions is appealing mainly because carbon dioxide is one of the leading causes of climate change. If we assume that individuals value this transgenerational environmental protection, we must account for this valuation of non-
49
U.S. Department of Energy, Benefits of Geothermal Heat Pump Systems
27
monetary environmental goods in our cost-benefit analysis.
This societal benefit is
mainly nonmonetary and may not necessarily bring economic benefits to Colgate, although we do argue this later in the section.
Many stakeholders in the Colgate
community will likely value the implementation of geothermal technology based on such values. Steve Bellona, the associate vice president for facilities and planning at Hamilton College, believes that such values were a driving reason for their implementation of geothermal technologies.
In an interview he mentioned Hamilton College believed
geothermal technology was simply “the right thing to do.” 50
Individuals in the
community will feel good about their contribution and thus value the technology. Retrofitting buildings to geothermal heating and cooling is feasible but geothermal is even more practical for new constructions. As the world becomes increasingly more environmentally conscious and LEED certification standards become widely accepted, it becomes more difficult for a non-profit institution such as Colgate to construct a new building without obtaining a LEED certification. If Colgate decided to make the new fitness center or any other proposed constructions LEED certified, using geothermal energy would aid in this process (See Appendix II for a more in depth recommendation of the implementation of a geoexchange system in the new fitness center). A geoexchange system would make buildings much more efficient and therefore much more eligible for LEED certification. 51 Under the guidelines of LEED certification, each building is assessed on a point system with points awarded for certain "green" aspects such as light pollution reduction and use of recycled materials. When it comes to energy efficiency, LEED awards up to 35 possible points. A geoexchange system has the 50
Bellona, Steve, personal communication Geothermal System Qualifies University For LEED Certification. The Chief Engineer. (2007, August). Retrieved from http://www.chiefengineer.org/content/content_display.cfm/seqnumber_content/3100.htm 51
28
potential to receive up to 19 points for optimized energy efficiency, up to 7 points for onsite renewable energy and 2 points for green power. While biomass is considered a carbon neutral, renewable energy source, the points earned by geothermal will end up being much higher than those earned from the use of our current heating plant because of the need to use fuel oil # 6 in the winter months to supplement woodchips.
Fuel oil #6 emits large amounts of greenhouse
gases. 52 By eliminating its use to heat any new buildings constructed by Colgate, we could make the building truly carbon neutral and optimize the building's energy performance. Furthermore, the price of woodchips could feasibly rise in the near future due to a heightened desire of similar institutions to become more carbon neutral, making geothermal more attractive financially. Not only could the use of geoexchange in general have nonmonetary benefits and aid in Colgate’s carbon neutral initiative, it could also have educational benefits. In the face of large budget cuts, tensions may be high among faculty and staff with the announcement of any new building constructions or renovations. Improving the efficiency of the building in question and advertising its environmental benefits has the potential to ameliorate this negative reaction. Furthermore, academic classes in Geology, Geography, and Environmental Studies could take field trips to the site and learn more about renewable energy. Space on a lobby wall could also be dedicated to explaining the geothermal system, which could encourage increased interest about the environment and renewable energy sources in the general student population.
52
U.S. Energy Information Administration (Date). Voluntary Reporting of Greenhouse Gases Program Fuel and Energy Source Codes and Emission Coefficients. Retrieved from http://www.eia.doe.gov/oiaf/1605/coefficients.html
29
Along the same lines, installing geothermal heating and cooling not only in new buildings but also in buildings along Broad Street as we recommended could create great public relations, enhancing Colgate's national reputation and appealing to prospective students. It is likely that Colgate would see some monetary benefits in the form of fundraising as well as nonmonetary benefits in the form of appeal of the school to potential applicants. These are all indirect benefits that should be considered in the decision making process for geothermal technology implementation.
Installing
geothermal systems would also allow us to catch up in terms of sustainability with some neighboring colleges such as Hamilton and Bard. The geology of Hamilton and Colgate is very similar, thereby showing that geothermal heating and cooling could also be successful at Colgate. There are important differences, though, between the two college campuses, such as the potential for outside funding, the higher price for electricity at Hamilton, and Hamilton’s use of electric heating units (see “Potential Funding” and Hamilton College Comparison” for more information on this topic).
A Condensed List of the Potential Benefits of Geothermal at Colgate: 1) Geothermal will lower Colgate's greenhouse gas (GHG) emissions and thus our ecological footprint will shrink. The reduction will be the result of decreased use of fuel oils for the heating and cooling of buildings on campus. 2) Colgate will be one step closer to meeting the requirements of the Presidents' Climate Commitment of which Colgate is a signatory. 3) Buildings will have a higher likelihood of becoming LEED certified. 4) Colgate will be better able to compete with similar collegiate institutions that are increasingly “out greening” us.
Hamilton College, just thirty minutes away, 30
already has three geothermal systems and is a competitor of Colgate when it comes to prospective students. 5) Geothermal technology will be good public relations for Colgate as sustainability becomes more and more important across the country and world. 6) The geoexchange systems will be a selling point for prospective students interested in the environment and a talking point on school tours. Being “green” is very important in today’s world, as can be seen in the sheer quantity of greenwashing taking place. The Princeton Review suggests that more prospective students and their parents than ever before understand climate change and are making decisions based on these concerns. 53 7) Geoexchange systems can generate nonmonetary benefits for the Colgate community. These benefits will come as those in the community understand that they are helping the environment.
While no quantitative data is available to
confirm this point, the students at Hamilton who know about the school’s geothermal systems do feel a sense of pride. 8) Students can become more environmentally informed and may begin to take a more vested interest in climate change and other environmental issues. Posters hung in buildings with geothermal heating and cooling coupled with informational talks with trained RA’s will heighten awareness. 9) Geothermal systems can be used as an education tool for teaching sustainability. It can be a resource that is applied to courses in various departments, such as energy-
53
Princeton Review (2009).College Hopes and Worries Survey. Retrieved from http://www.princetonreview.com/uploadedFiles/Test_Preparation/Hopes_and_Worries/colleg_hopes_worr ies_details.pdf
31
and climate-focused First-Year Seminars as well as Geology, Geography, and Environmental Studies courses. 10) A positive difference between geothermal and other renewable energy resources is that geothermal systems are completely underground and not visible other than the small pumps that can be easily contained in maintenance rooms. All the land above the wells can still be used for other activities, although digging is not encouraged. 54
Hamilton College Comparison Hamilton College has successfully installed two geothermal heating and cooling systems and is in the process of installing a third in its newly renovated Student Union building. All three systems are vertical closed-loop systems with a glycol solution running through the pipes. The first installation occurred in the atrium of their science building over five years ago and the second system is in a newly renovated residential house and provides 100 percent of the heating and cooling needs for the building. While the system in the atrium of the science building was a trial run and will not become economically practical for at least a hundred years, it allowed the college to test the system and be sure of its effectiveness. 55 Colgate must take this initial step and install geothermal in a building on campus to at least test its practicality. The second building that Hamilton installed geothermal heating and cooling in was a dorm that was being renovated. The dorm has a 21,000 square foot floor plan, sleeps 51 students, and now receives 100 percent of its heating and cooling from geoexchange. Each room within the dorm has its own heat pump and thus residents are
54 55
Tolme, Paul, Universities Lead the Charge to Mine the Heat Beneath our Feet. Bellona, Steve, personal communication
32
able to control their own room temperatures. This is a technology that Colgate should explore. The entire system cost about $85,000 more than a traditional heating system would have cost to install, although $80,000 of this cost was due to the cost of drilling 16 wells and Hamilton was able to offset much of this cost with a $48,000 subsidy from NYSERDA. The college estimates that it will break even on the energy costs of this building in two to three years. The success of geothermal heating and cooling in this dorm led Hamilton to begin a similar project in their next construction endeavor, the Student Union building. 56
The achievements of geothermal heating and cooling at
Hamilton lends great credence to the idea that geothermal energy can be successful and cost efficient here at Colgate.
Figures 17 and 18: Images of a small room on the first floor that contains the only above-ground aspects of Hamilton’s dorm’s geothermal system except for the small heat pumps in each room. Figure 17 shows the 16 well heads as they come in from the ground outside and circulate through the building. Figure 18 is of the glycol solution that circulates through the closed-loop pipe outside.
Potential Funding Many projects that include renewable energy in renovations or new construction can receive funding from both local and national organizations. According to Sean 56
Ibid
33
Graham, the Director of Public Works and MUC Civil Defense in the Village of Hamilton, the Independent Energy Efficiency Projects (IEEP) offers compensation of up to $10,000 for energy efficient projects such as geothermal systems. 57 The New York State Energy Research and Development Authority (NYSERDA) also offers incentives for renovations and new construction that incorporate renewable energy systems. 58 However, in order to be eligible for NYSERDA funding, Colgate would have to pay the New York State System Benefits Charge. 59 The school’s electricity comes from a municipal grid as opposed to a state run grid, so it does not pay the New York State System Benefits Charge and Colgate is ineligible for funding from NYSERDA. The Regional Greenhouse Gas Initiative (RGGI) is an organization working to reduce greenhouse gas emissions in the northeastern and mid-Atlantic states through Cap-and Trade. 60 RGGI is also offering incentives for decreases in carbon emissions through decreases in electricity consumption. The American Recovery and Reinvestment Act of 2009 invested 16.8 billion dollars into energy efficiency and renewable energy. Some of this money is being distributed through the Department of Energy as grants, with millions of dollars available for geothermal systems. 61
There are many programs that offer
funding for renewable energy projects like geothermal, although a major obstacle to accessing these funds is electricity use.
57
Graham, Sean, personal communication New York State Energy Research and Development Authority (2004). Incentives. Retrieved from http://www.nyserda.org/incentives.asp 59 New York State Energy Research and Development Authority (2004). Frequently Asked Questions. Retrieved from http://www.nyserda.org/programs/New_Construction/faqs.asp 60 Regional Greenhouse Gas Initiative. (2009) Welcome. http://www.rggi.org/home 61 U.S. Department of Energy (2008, December). Recovery and Reinvestment. Retrieved from http://www.energy.gov/recovery/renewablefunding.htm#GEOTHERMAL 58
34
Potential Obstacles All research points to the idea that Colgate should pursue geothermal on campus and should start with the houses on Broad Street recommended in Table 1. Despite the feasibility of geothermal on Colgate’s campus, there are some potential roadblocks. These obstacles will come in the form of the initial costs and also from the potential regulations by the Village of Hamilton. The financial costs of implementing geothermal energy are enumerated above, so this section will focus more on the Village’s regulations. The main concerns of the village, according to Sean Graham, are keeping the drinking water safe and keeping electricity prices stable. If an open-loop system were ever to be considered, Colgate would need to supply the town with a detailed engineering report; a geologic survey; and a survey showing how the system would affect landowners, groundwater, and drinking water; Colgate would also need to comply with annual inspections of the system. 62 A backflow valve would also need to be installed on all pipes. There are no village regulations for digging or installing a closed-loop system that does not affect groundwater. The potential problem is that groundwater is located very close to the earth’s surface on Colgate’s campus and thus the school would have to spend time, money, and energy to fill out forms and make sure that every precaution was taken to protect the distribution system of the village’s potable water. The village is also very concerned with rising electricity costs that could come with geothermal energy use, as these systems could require higher levels of electricity consumption. The town is allotted ten megawatt hours of hydroelectric energy per month 62
Graham, Sean, personal communication
35
at a price of one dollar per megawatt hour. When the town consumes more than this allotment, the price jumps drastically to $7.99 per megawatt hour. 63 Hydroelectric power allows the electricity costs for the village to remain around four cents per kilowatt hour and this could rise if geothermal energy was used. Overall, the town does not have any regulations against geothermal. However, it does have certain rules to protect drinking water and requires permits that need to be obtained prior to digging. 64
A Condensed List of the Potential Barriers of Geothermal at Colgate: 1) The initial costs of installing a geoexchange system and digging exploratory wells is high. 2) Regulations from the Village of Hamilton in the form of protecting drinking water and keeping electricity consumption down may provide some resistance. 3) Geoexchange systems have the potential to increase electricity consumption.
Next Steps: In order for Colgate to take geothermal energy into serious consideration there are certain steps that must be taken immediately. First and foremost Colgate must evaluate its true commitment to sustainability and realistically define what it is working toward. If Colgate decides to follow through with geothermal energy, a second important step will be to hire an engineer to construct a proposal for the location and depth of the wells for the Broad Street houses recommended in this paper. Despite our recommendations to use
63 64
Graham, Sean personal communication Ibid
36
a close-loop vertical system, the same engineer should also determine the most effective technologies and the exact capacity that the system will require. Determining the most effective technologies for each location will be a pivotal decision as it will have a large impact on the success of the system. In order for this to be determined, a test well will need to be drilled on a proposed site for thermal response testing.
This test will
determine how deep the geothermal wells will need to be as well as exactly how many wells will need to be dug to sufficiently heat and cool the building. Once a proposal has been written, Colgate will need to work closely with the Village of Hamilton to comply with regulations associated with digging the wells as well as consider issues associated with electricity consumption.
Conclusions: The adoption of geothermal energy at Colgate is an expensive investment in the short term. The costs to install the new technologies will be high, especially if a fully functioning heating system exists. However, the long-term environmental, economic, and social payback of an investment in geothermal energy is large. Cutting out the use of fuel oil #2 will reduce greenhouse gas emissions and, therefore, Colgate’s carbon footprint. For a large percentage of fuel oil #2 buildings and especially those on Broad Street, geothermal will be cost effective and begin saving Colgate money within thirty years of installation.
Finally, having a geothermal system on campus will provide future
educational opportunities as well as increased environmental awareness. There are many examples of colleges and institutions in the northeast that have invested in geoexchange systems, and it seems that this is a logical next step for Colgate to pursue. We 37
recommend that initial systems be installed along Broad Street where the payback is shortest and the space for wells is available.
Acknowledgements We would like to thank Peter Darby, Thomas Myers, Steve Bellona, Sean Graham, Bruce Selleck, John Pumilio, and Bob Turner for their help with this project. Each served as excellent resources for data, information, and firsthand experience. The latter two were excellent advisors to the research and writing processes. Thank you all!
38
Appendix I:
49 Broad
8344.00
28425.00
1279.13
Avg. Cost Fuel Oil #2 ($/yr) (‘07-‘09) 12835.07
42500.00
6.42
Rounded to Nearest Even Number 8.00
42496.00
239000.00
Current Total Heating Cost ($/yr) 14114.20
325275.13
1279.13
68 Broad
13050.00
85280.00
3837.60
6760.42
26.10
27.00
13500.00
10.04
12.00
63744.00
358500.00
10598.02
439581.60
3837.60
70 Broad
6244.00
22870.00
1029.15
6213.09
12.49
13.00
32500.00
4.80
6.00
31872.00
179250.00
7242.24
244651.15
1029.15
80 Broad
8770.00
93930.00
4226.85
12875.18
17.54
18.00
45000.00
6.75
8.00
42496.00
239000.00
17102.03
330722.85
4226.85
84 Broad
19000.00
84780.00
3815.10
16447.55
32.90
33.00
82500.00
14.62
16.00
84992.00
478000.00
20262.65
649307.10
3815.10
92 Broad
13698.00
58660.00
2639.70
24116.75
48.23
49.00
122500.00
10.54
12.00
63744.00
358500.00
26756.45
547383.70
2639.70
Location
Building Sq. Ft.
Avg.Electric Use (kwh/yr) (‘07-‘09)
Avg.Electric Costs ($/yr) (‘07-‘09)
Number of Heating Units Required 16.69
Rounded to Nearest Whole Number 17.00
Total Cost of Heating Units ($)
Number of Wells Required
Total Cost of Wells ($)
Total Mechanical System Costs
Potential First Year Geothermal Costs ($/yr)
Potential Costs of Geothermal Thereafter ($/yr)
94 Broad
10830.00
69729.00
69729.00
16498.46
21.66
22.00
55000.00
8.33
10.00
53120.00
298750.00
19636.27
410007.81
1045.94
102 Broad
6722.00
49166.00
2212.47
6872.50
13.44
14.00
35000.00
5.17
6.00
31872.00
179250.00
9084.97
248334.47
2212.47
116 Broad
4700.00
17940.00
807.30
5326.86
9.40
10.00
25000.00
3.62
4.00
21248.00
119500.00
5326.86
165748.00
807.30
118 Broad
8770.00
93930.00
4226.85
12875.18
17.54
18.00
45000.00
6.75
8.00
42496.00
239000.00
17102.03
330722.85
4226.85
10830.00
69729.00
3137.81
16498.46
21.66
22.00
55000.00
8.33
10.00
53120.00
298750.00
19636.27
410007.81
3137.81
5483.00
52475.00
2361.38
4164.53
10.97
11.00
27500.00
4.22
6.00
31872.00
179250.00
6525.91
240983.38
2361.38
5617.00
57040.00
2512.80
8961.99
11.23
12.00
30000.00
4.32
6.00
31872.00
179250.00
11474.79
243634.80
2512.80
4100.00
25625.00
1153.13
5472.08
8.20
10.00
25000.00
3.15
4.00
21248.00
119500.00
6625.21
166901.13
1153.13
5040.00
16967.00
763.52
6845.48
10.08
10.00
25000.00
3.88
4.00
21248.00
119500.00
7608.99
166511.52
763.52
67000.00
67000.00
3015.00
34445.27
134.00
134.00
335000.00
51.54
52.00
276224.00
1553500.00
37460.27
2167739.00
3015.00
6835.00
157600.00
7092.00
3671.85
7.34
8.00
20000.00
5.26
6.00
31872.00
179250.00
10763.85
238214.00
7092.00
1476.00
19135.00
861.08
2325.80
2.95
4.00
10000.00
1.14
2.00
10624.00
59750.00
3186.88
81235.08
861.08
13886.00
139232.99
6265.48
22564.72
27.77
28.00
70000.00
10.68
12.00
63744.00
358500.00
28830.20
498509.48
6265.48
5518.00
20000.00
900.00
5565.53
11.04
12.00
30000.00
4.24
6.00
31872.00
179250.00
6465.53
242022.00
900.00
2783.00
11926.84
536.71
3598.70
7.20
8.00
20000.00
2.14
4.00
21248.00
119500.00
4135.41
161284.71
536.71
8375.00
11945.00
537.53
5304.60
10.61
11.00
27500.00
6.44
8.00
42496.00
239000.00
5842.13
309533.53
537.53
2545.00
55030.00
2476.35
5628.41
5.09
6.00
15000.00
1.96
2.00
10624.00
59750.00
8104.76
87850.35
2476.35
4507.00
17440.00
784.80
8385.01
9.01
10.00
5000.00
3.47
4.00
21248.00
119500.00
9169.81
146532.80
784.80
Chapel House Conant House Cultural Center French / Italian House Preston Hill Apartments Sanford Field House Seven Oaks Club House Seven Oaks Maint Bldg Sigma Chi Watson House 79 Hamilton 59 Hamilton 88 Hamilton 13 East Kendrick
39
Table 2 displays the costs for heating and cooling all buildings on campus currently using fuel oil #2 and the potential costs if those were retrofitted for geothermal heating and cooling instead. The square footage, average electricity use, and average costs for fuel oil #2 were all collected from Colgate’s Buildings and Grounds. Current fossil fuel prices are assumed to continue indefinitely. The cost of electricity was created by multiplying the consumption (in kWh) by .045 because the average cost of electricity in Hamilton is around 4 cents. The numbers of heat pumps, wells, and other mechanicals supplies as well as their respective costs were calculated based on numbers used by Hamilton College. For every 500 sq ft of building, one ton of heating capacity is required (you can get heat pumps in the one ton variety and place them in each room or have bigger pumps with heat ducts) and each ton of heating capacity costs around $2,500. For every 1,300 sq ft of building, one well is required and when this is calculated it must be rounded up to the nearest even number because for every well that goes down another must come up. This means that each building will have more capacity to heat then necessary. For each well, the digging costs around $5,312 but this will be very dependent on the location. Finally the mechanical costs of the system, including piping, the glycol solution, labor, etc., will cost about $29,875 per well.
Appendix II: Recommendation for the Implementation of a Geoexchange System in the Fitness Center Construction Project (Edited version of the document presented to Lyle Roelofs, Interim President of Colgate University, on November 20, 2009)
In its most basic form, geothermal energy is energy that originates in the earth and flows naturally up into the atmosphere. Natural sources of geothermal energy include volcanoes, hot springs, and geysers. Most naturally occurring sources of geothermal energy in the United States are located on the west coast because of the amount of plate tectonic activity that is required to force geothermal energy to the surface. Technology has also allowed humans to extract this energy through shallow or deep well systems. Humans can use high temperature geothermal resources to generate power or directly heat buildings or we can capitalize on the temperature differential between the subsurface and the air to heat or cool buildings using heat exchange technology. At depth the earth is warmer because heat energy is created within the core as radioactive particles in rocks 40
constantly decay. Closer to the surface, the aquifers and the earth are at a constant temperature that does not vary seasonally because it is heated by radiation from the earth’s core but is insulated from above surface temperature variations. Geothermal heat exchange technology currently exists that allows us to use this natural difference to our advantage. As global climate change increases environmental pressures across the world, and reliance on foreign oil continues to place political and economic pressures on the United States and other western countries, geothermal solutions are becoming more attractive energy alternatives. As a clean, renewable, reliable, and domestic source of energy, there is great potential for the use of geothermal energy across the United States, but also at Colgate University. Installing geothermal heating and cooling capabilities in the newly planned fitness center could be a great step toward creating a greener Colgate. As signatory to the American College and University Presidents' Climate Commitment (ACUPCC), Colgate has committed itself to carbon neutrality and geothermal heating and cooling could aid in this attempt. Geothermal heating and cooling would also be a huge advantage if the goal of the fitness center were to attain LEED certification. The alternative plan would be to connect the new fitness center to the central heating plant, which is powered by woodchips. While this source is technically considered carbon neutral, the validity of the plant's neutrality is questionable. When the temperature drops below 35-40 degrees the plant must supplement heating with fuel oil # 6. This temperature threshold, already well within normal temperature ranges for central New York, would almost certainly raise if the fitness center were added to the system as prior to construction of the Ho Science Center the temperature threshold was as low as 30 degrees. Furthermore, through basic
41
economics, we can expect prices for woodchips to rise as becoming "green" becomes more popular in central New York. As the central plant already accepts up to 33 tons of woodchips per day, this cost could be significant. As the world becomes increasingly environmentally conscious and with the wide acceptance of LEED certification standards, it becomes more difficult for a non-profit institution such as Colgate to construct a new building without getting it LEED certified. If Colgate decided to make the fitness center LEED certified, using geothermal energy would aid this process. A geothermal heat exchange system would make the building much more efficient and therefore much more eligible for LEED certification. The way LEED certification works, each building is assessed on a point system with points awarded for certain "green" aspects such as light pollution reduction and use of recycled materials. When it comes to energy efficiency, LEED awards up to 35 possible points. A geothermal heat exchange system has the potential to receive up to 19 points for optimized energy efficiency, up to 7 points for on-site renewable energy, and 2 points for green power. Biomass is considered a carbon neutral, renewable energy source, however in the end the points earned by geothermal will end up being much higher than those earned from the utilization of our current heating plant because of the need to use fuel oil # 6 in the winter months to supplement the woodchips. Fuel oil #6 emits large amounts of greenhouse gases. By eliminating its use to heat the new fitness center we could make the building truly carbon neutral and optimize the building's energy performance. Not only could the use of geothermal in general, and specifically with the fitness center, aid in Colgate’s carbon neutral initiative, it could also have nonmonetary benefits including educational benefits. In the face of large budget cuts, tensions may be high
42
among faculty and staff with the announcement of a new fitness center. Improving the efficiency of the building and advertising its environmental benefits has the potential to improve this reaction. Furthermore, academic classes in the geology and geography departments could take field trips to the site and learn more about renewable energy. Space on a wall in the lobby could also be dedicated to explaining the geothermal system, which could encourage increased interest about the environment and renewable energy sources in the general student population. Along the same lines, installing geothermal heating and cooling in the fitness center could be good for Colgate's national reputation and appeal to prospective students. It would also allow us to catch up in terms of sustainability with some neighboring colleges such as Hamilton. Hamilton College currently has geothermal heating and cooling in two buildings and is installing a third system in its newly renovated student center. The first installation occurred in the atrium of their science building and the second system is in a residential house and provides 100 percent of the heating and cooling for the building. The geology of the two schools is very similar, thereby showing that geothermal heating and cooling could also work at Colgate. While the system in the atrium of their science building was a trial run and will not become economically practicable for at least a hundred years, it allowed them to test the system and be sure of its effectiveness. We recommend that Colgate make a similar decision for the fitness center. While it may not be economically viable in the short run, because of its proposed location near the heating plant, it would be a great trial run of the technology at Colgate. Estimates show that a geothermal heat exchange system would require a significant upfront investment of about $100,000 more than the cost of connecting the
43
building to the central heating plant (see table 3). The cost of internal piping and ventilation infrastructure will be comparable to the alternative. If the system is implemented correctly we can expect reduced annual energy costs to pay back this initial investment. Heating Unit Prices
Well System Prices
Total Additional Cost
Geothermal Heating $50,000 $42,496 $92, 496 and Cooling Table 3: The cost of geothermal heating and cooling in the proposed fitness center. The price for heating units and the well system were estimated using the proposed heatable square footage and the costs for materials at Hamilton per square foot. To potentially make the new fitness center more economically efficient with geothermal heating and cooling, we recommend the use of lower ceilings to reduce the area that requires heating.
44
Works Cited Aquifers Under Colgate Campus Buildings. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] Author. (2007, August). Geothermal System Qualifies University For LEED Certification. The Chief Engineer. Retrieved from http://www.chiefengineer.org/content/content_display.cfm/seqnumber_content/31 00.htm Backyards of Broad Street Houses. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] Bellona, Steve(personal communication, 10-23-09) Blackwell, D. D., and Richards, M. 2004. Geothermal Map of North America. American Assoc. Petroleum Geologist (AAPG), 1 sheet, scale 1:6,500,000. Brown, Lester (2003). Plan B: Rescuing a Planet under Stress and a Civilization in Trouble. New York: W.W. Norton & Co. California Energy Commission (2006). Geothermal or Ground Source Heat Pumps. Retrieved from http://www.consumerenergycenter.org/home/heating_cooling/geothermal.html Colgate Campus Buildings by Heat Source. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] Colgate University, Buildings and Grounds (2009) [Campus Energy Consumption Data by Building]. Unpublished Raw Data. Darby, Peter (personal communication, 9-28-09; 10-1-09) Geothermal Energy. (2009). In Encyclopedia Britannica. Retrieved from http://search.eb.com/eb/article-9036528 Geothermal Heat Pump Consortium. (2007). Information for Evaluating Geoexchange Applications (2nd ed). Washington, D.C.: Author Graham, Sean (personal communication, 12-4-09) László, E. (1981). Geothermal Energy: An Old Ally. Ambio, 10(5), 248-249.
45
MIT-led Interdisciplinary Panel. (2006). The Future of Geothermal Energy: Impact of Enhanced Geothermal Systems (EGS) on the United States in the 21st Century. Cambridge, MA.: Tester, Jefferson et al., section 2.2.6
Myers, Thomas (personal communication, 10-1-09) National Renewable Energy Laboratory (1998). Direct Use of Geothermal Energy. Washington, D.C.: Author. New York State Energy Research and Development Authority (2009). Energy Efficiency Measures at New College Dorm Complex. Retrieve from http://www.nyserda.org/Programs/New_Construction/Case_Studies/bardcollege.p df New York State Energy Research and Development Authority (2004). Frequently Asked Questions. Retrieved from http://www.nyserda.org/programs/New_Construction/faqs.asp New York State Energy Research and Development Authority (2004). Incentives. Retrieved from http://www.nyserda.org/incentives.asp Priebe, Maryruth (2009, September) Hot and Steamy: Ground-Source on Campus. Retrieved from http://www.nwf.org/campusEcology/climateedu/articleView.cfm?iArticleID=102 Princeton Review (2009).College Hopes and Worries Survey. Retrieved from http://www.princetonreview.com/uploadedFiles/Test_Preparation/Hopes_and_Wo rries/colleg_hopes_worries_details.pdf Regional Greenhouse Gas Initiative. (2009) Welcome. http://www.rggi.org/home Selleck, Bruce (personal communication, 9-18-09) Types of Bedrock Under Colgate Campus Buildings. [computer map]. New York State GIS clearinghouse. Albany, NY. 2009. Using USGS [GIS software] Tolme, Paul (2008, September) Universities Lead the Charge to Mine the Heat Beneath our Feet. Retrieved from http://www.nwf.org/campusEcology/climateedu/geothermal.cfm U.S. Department of Energy (2008, September). Geothermal Basics. http://www1.eere.energy.gov/geothermal/geothermal_basics.html U.S. Department of Energy (2008, September). Hydrothermal Power Systems. http://www1.eere.energy.gov/geothermal/powerplants.html 46
U.S. Department of Energy (2008, November). A History of Geothermal Energy in the United States. http://www1.eere.energy.gov/geothermal/history.html U.S. Department of Energy (2008, December). Benefits of Geothermal Heat Pump Systems. Retrieved from http://www.energysavers.gov/your_home/space_heating_cooling/index.cfm/myto pic=12660 U.S. Department of Energy (2008, December). Recovery and Reinvestment. Retrieved from http://www.energy.gov/recovery/renewablefunding.htm#GEOTHERMAL U.S. Department of Energy (2008, March). Direct Use of Geothermal Energy. Retrieved from http://www1.eere.energy.gov/geothermal/directuse.html U.S. Energy Information Administration (Date). Voluntary Reporting of Greenhouse Gases Program Fuel and Energy Source Codes and Emission Coefficients. Retrieved from http://www.eia.doe.gov/oiaf/1605/coefficients.html
47
