Developing Demand Side Management Program for ...

International Conference on Electrical, Computer and Communication Engineering (ECCE), February 16-18, 2017, Cox’s Bazar, Bangladesh

Developing Demand Side Management Program for Residential Electricity Consumers of Dhaka City Ayman Uddin Mahin, Md. Adnan Sakib, Md. Asif zaman, Md. Shahed chowdhury, Saik Ahsan Shanto Department of Electrical and Electronic Engineering, Ahsanullah University of Science and Technology Dhaka, Bangladesh [email protected] Abstract— In Bangladesh, electricity consumption is higher than the generation and demand of electricity is increasing day by day. Due to this, load shedding is occurring which affects the daily life. This problem can be solved by increasing generation which involves setting up new generating units and change in transmission lines, which are costly. Another approach to solve this problem is demand side management. It is a process of reducing energy consumption at user end. Using demand side management, energy consumption can be reduced at no or very little cost. At the same time, it also reduces the use of energy resources. So, environment is also less affected. Three Demand side management tools: energy efficiency, direct load control and time of use have been applied and significant amount of electrical energy can be saved using energy efficiency.

Fig. 1. Electrical energy consumption of different types of consumers in Dhaka[1]

To the best of our knowledge, no methodology has been proposed to bring the residential customers of Dhaka city under demand side management program. If demand side management program can be used, electrical energy consumption will be reduced. So, it will reduce the necessity of installing new generating units or turning units on during peak period.

Keywords— Demand side management, demand response, time of use, direct load control, load shifting, energy efficiency.

I. INTRODUCTION The demand of electricity is increasing day by day. Due to this, new generators or power plants are required. Increasing number of power plants refers increasing use of energy resources. We have limited resources of energy on earth. So, it is necessary to control the demand of electricity. Demand side management is a sum of techniques and strategies which helps us to control energy use at user end. It prevents the necessity of new generator or power plant and change of transmission lines and other equipment’s up to a certain limit. If residential users become concerned about demand side management, they can save their money by reducing energy demand. A little saving in everyday can generate huge saving at the end of a year. The objectives of the paper are: to develop an average load profile/curve for residential users of Dhaka city and to apply demand side management tools to reduce energy consumption.

Section II gives idea about demand side management, section III focuses on the methodology used, section IV shows the results obtained and section V reflects the summary of the paper. II. DEMAND SIDE MANAGEMENT

A. Demand side management (DSM) Demand Side Management (DSM) is a set of techniques applied on the consumer’s side to reduce energy consumption. Demand side is the side that demands for electrical energy. The side can be residential, industrial or commercial. DSM is used by utilities to control the loads in order to achieve a better overall network performance and to obtain a better match between the available supply and the consumer demand, so that their connection to the grid is scheduled according to the availability or cost of power. In other words, DSM is the implementation of those measures that help the consumers to reduce energy consumption and cost [2].

Total demand of electricity in Bangladesh is increasing day by day. Figure 1 show that among different types of consumers (residential, industrial, and commercial), use of electrical energy is higher in the case of residential consumers.

B. Approach to DSM DSM can be classified into two parts. The first one is “energy efficiency” (EE). In this method, the main concern is to save electricity. To do so, we must use energy efficient

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when electricity is used and how much is used. In California of USA, summer has three rate-periods: off-peak, partialpeak and peak. Winter has two rate periods: offpeak and partial-peak. Time-of-use rate plans at all other times will be lower than the peak rate [4]. When the demand is high the price of electricity should be high and when demand is low price should be low.

appliances. Energy conservation can also be considered as a part of energy efficiency method. Second one is “demand response” (DR). Demand response can be divided into: time of use, direct load control and load shifting. In time of use method, consumers are allocated different time to use electricity. Different time schedules provide different pricing range. This encourages customer to use energy in a moderate way and allows provider to manage the supply. In the case of direct load control, load can be controlled by the suppliers. Some loads are turned off for a limited period to save energy. The last one is load shifting. It is the process of shifting load from peak-hours to off-peak hours. Load shifting is of two kinds: indirect load shifting and automatic load shifting. Figure 2 shows how DSM can be classified.

E. Direct load control In direct load control method supplier can control the supply of electricity directly. During the pick hour if any consumer uses more than a certain amount of energy the supplier can limit that consumer’s consumption. For example, if the suppliers’ setup a frequency sensitive relay and a controller with every connection which will open the relay after a certain amount of electricity consumed by the controller in pick hour it will fulfill the purpose of direct load control. Not all the devices are suitable for direct load control. Devices like refrigeration load, heating and cooling devices are suitable for this. Maximum interruption time can be from 30 minutes to 1 hour and it can be applied for 2-3 times a day. The impact should be small such that it should not be noticed by the consumers [5].

Demand side management

Demand Response

Energy Efficiency

F. Load Shifting Load shifting is such a process where the load is shifted and it does not make any change in the amount of consumed energy. Demand Side Management programs using loadshifting techniques show good potential for reducing the peak loads in the network demand pattern. It focuses on scheduling smart household appliances from peak load periods to offpeak periods. The aim is to increase the efficiency of the system by bringing both demand and supply to the best possible low value. Figure 3 gives an idea about load shifting [6].

Time of use

Direct load control

Load Shifting Fig. 2. General classification of DSM

C. Demand Response (DR) Demand response means voluntarily reducing demand. No modification is done on the consumer’s side. Demand Response is being more and more essential for the market and for the energy system. Shifting energy from peak hours to offpeak hours and hence distribute the load is one way to manage the demand side. These peaks are both costly to handle and a threat to the climate since marginal production technologies can be expensive and are usually fossil based. Shifting/reducing energy can be done by demand response and there are plenty of customer participating programs for this purpose. Some features of DR: market driven, user controlled, penalty for non-compliance, consumers are given opportunity to earn money in energy market [3].

Fig. 3. Load shifting curve [7]

From the above illustrated load shifting curve, the load from peak period has been distributed to off peak period. Peak period usually involves higher price of electricity than that during off-peak. So, users can save money by shifting load from peak period to off-peak period. Encouraging consumers to shift their load is done by encouraging consumers or implementing electronic messaging service that reminds consumers about load shifting.

D. Time of use Instead of a single flat rate for energy use, variable price is providing in this method. Time-of-use (TOU) pricing is a variable rate structure that charges for electrical energy depending on the time of day and the season the energy is used. With time-of-use rates, bill will be determined by both

G. Energy Efficiency

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Energy Efficiency is a DSM tool which is used to reduce energy consumption by replacing normal appliances by energy efficient appliances. In this method, the main concern is to save electrical energy. To do so, we must use energy efficient equipment’s. Energy conservation can also be considered as a part of this method.

Fig. 4. Effects of energy efficiency [8]

Fig. 6. Average share of energy consumption by various loads

Figure 4 shows how using of energy efficient appliances reduce the total energy consumption. If more efficient appliances are used, more save in energy can be achieved.

Figure 6 shows the relative contribution of different types of loads that are generally used by a residential user on an average. The calculation has been done on the basis of energy consumption. As every household has at least one fridge/ refrigeration unit which is kept ON for 24 hours/day, energy consumption due to fridge turns out to be the largest share in residential energy consumption scenario. Different types of loads are used at different times. Some loads are kept ON for all day long where as some loads are used for a limited period.

III. METHODOLOGY

Fig. 5. Methodology

Figure 5 shows the methodology regarding DSM. Necessary information should be collected using questionnaire. It should involve the number of different types of loads and time of using the loads. Using these, load profile can be developed. After that, DSM tools can be applied and benefits can be calculated. IV. RESULTS AND ANALYSIS Results are obtained by analyzing statistical data collected through survey. 32 residential houses in Japan garden city mohammadpur, Dhaka have been taken into consideration in this case. Demand side management tools (Energy efficiency, direct load control and load shifting) have been applied. Average daily load curve, contribution from each load, daily average load curve after applying DSM tools have been developed and analyzed. Fig. 7. Daily average load curve

The daily average load curve in figure 7 shows the pattern of using loads of a household on an average. From the load curve, we can see that the peak consumption occurs during 9:00pm–9:30pm.Contribution from lighting load, fan and TV

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can be reduced by using energy efficiency methods. Some particular loads can be shifted. Water heater, washing machine and water pump have shifting potential. Some loads like fridge and AC can be subjected to direct load control method. A. Impact of energy efficiency Light, fan and TV have been replaced by energy efficient light, fan and TV respectively. Replacement of fluorescent lamp of 40W and energy saving bulb of 23W with LED tube light of 14.5W; fan of 75W with energy efficient fan of 31W, TV of 100W with LED TV of 48W have been done. Resulted load curve is shown in figure 8.

Fig. 9. Daily average load curve after applying DLC

C. Impact of load shifting According to load shifting method, some loads when energy consumption is very high can be shifted to the region where energy consumption is comparatively low. Different tariffs are provided for peak hour and off peak hour. High tariff is provided for peak hours. By shifting loads from peak hours cost can be reduced. It also reduces the necessity of turning on additional generating units. Water heater and water pump can be shifted from peak hour(5:00pm – 11:00pm) to off-peak hour(11:00pm - 5:00am).Load curve after shifting water heater and water pump is shown in figure 10.

Fig. 8. Energy efficient daily average load curve

B. Impact of direct load control According to direct load control method, some particular loads can be turned off by the suppliers for a limited time. Turning off these loads do not affect the operations of these appliances. By applying this DSM tool, some amount of energy can be saved every day. Here, Fridge is kept off during 9:00pm-9:30pm.AC is kept off during 8:30pm-9:00pm and 9:30pm-10:00pm.The resulted daily average load curve is shown in figure 9.

Fig. 10. Daily average load curve after shifting load

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shifting, 1.42% of average daily energy consumption can be shifted from peak hours to off peak hours. Demand side management tools can be applied easily by little or no cost. As load profile has been developed on the basis of field data, it may contain error. More precise load curve can be developed by increasing the number of segments in the axis of time. Future scopes involves solar system, incentive based pricing, peak and off-peak pricing, DSM for commercial and industrial users.

D. Unit saved/shifted Unit saving calculation for energy efficiency: Average load per day = 745.66W Total units consumed per day = 745.66 W X 24 h = 17895.84 Wh = 17.89584 units After working on energy efficiency:

ACKNOWLEDGMENT

Average load per day = 598.294W

Starting with thanking the Almighty, we would like to express our deep gratitude to our respected supervisor, Dr. Tareq Aziz, Associate Professor, Department of EEE, Ahsanullah University Of Science and Technology, for his patient guidance, enthusiastic encouragement and valuable support throughout the work.

Total units consumed per day = 598.294W X 24 h = 14359.056 Wh = 14.359056 units Total units saved = (17.89584 – 14.359056) = 3.536782 units/day

REFERENCES

So, 19.76% of average daily energy consumption can be reduced.

[1]

Unit saving calculation for direct load control: Total units saved= (274.218 + 187.5 + 225) X 0.5

[2]

= 343.359 Wh/day = 0.343359 KWh/day = 0.343359 unit/day

[3]

In this case, 1.92% of average daily unit consumption can be saved.

[4] [5]

Unit shifting calculation for load shifting: Energy shifted for water heater = (62.5 X 0.5)

[6]

= 31.25 Wh/day

[7]

Energy shifted for water pump = (445.285 X 0.5) [8]

=222.6425 Wh/day Total units shifted =(31.25 + 222.5425) =253.8925 Wh/day =0.2539 unit/day 1.42% of total average daily unit consumption can be shifted from peak-hours to off-peak hours. V. CONCLUSIONS Among the three DSM tools: energy efficiency, direct load control and load shifting, energy efficiency shows better result. Noticeable amount of energy can be saved by replacing normal appliances with energy efficient appliances. So, this method should be given priority to reduce energy consumption. Using energy efficiency appliances 19.76% of average daily energy consumption can be reduced which results in reduction of emission of carbon dioxide by 2.10 kg. For direct load control method 1.92% of average daily consumption can be reduced which results in reduction of emission of carbon dioxide by 0.20 kg. In the case of load

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Sujit Kumar Sikder , Francis Eanes , Henok Birhanu Asmelash , Shiba Kar and Theo Koetter , “The Contribution of Energy-Optimized Urban Planning to Efficient Resource Use–A Case Study on Residential Settlement Development in Dhaka City, Bangladesh” ,5 February 2016 Abdel-Baset Mostafa Imbarek Ihbal, “Investigation of Energy Demand Modeling and Management for Local Communities: Investigation of the Electricity Demand Modeling and Management Including Consumption Behaviour, Dynamic Tariffs, and Use of Renewable Energy” University of Bradford, 2012 Demand side management and demand response in municipalities, IndEco Strategic Consulting Inc. , 27 January 2004 Ahmad Faruqui,RyanHledik and Jennifer Palmer , “Time-Varying and Dynamic Rate Design” Ciara O’Dwyer,“Modelling Demand Response in the Residential Sector”, August, 2011 Maurits de Blécourt, “Load-shifting in a new perspective” January, 2012 DSM system, Available at:http://etap.com/smart-grid/smart-griddemand-management.htm?lang=en-US (last accessed on october 31, 2016) Demand Response and Demand Side Management What’s the Difference?, Available at: http://www.energyadvantage.com/blog/2010/02/demand-responsedemand-side-management-what%E2%80%99s-difference/ , (last accessed on October 31, 2016 )