1. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
INTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
& TECHNOLOGY (IJEET)
ISSN 0976 – 6545(Print)
ISSN 0976 – 6553(Online)
Volume 4, Issue 1, January- February (2013), pp. 124-130
IJEET
© IAEME: www.iaeme.com/ijeet.asp
Journal Impact Factor (2012): 3.2031 (Calculated by GISI) ©IAEME
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A REALISTIC ESTIMATION OF ENERGY SAVING WITH
RENEWABLE ENERGY SOURCES IN DOMESTIC SECTOR
A.Srinivasa Rao1, S.V. L. Narasimham2 and B.Suresh Kumar3
1
Department of Electrical and Electronics Engineering, GITAM University, Visakhapatnam-
530045, India
2
Department of Information Technology, JNT University, Hyderabad-500085, India
3
Department of Electrical and Electronics Engineering, GITAM University, Visakhapatnam-
530045, India
ABSTRACT
Electrical energy is the unchallenged prime mover of the modern human life. The
demand for the energy is constantly increasing in developing countries like India, where the
generation of power is predominantly by fossil fuels. Because of the various disadvantages
associated with fossil fuels besides the economic constraints, it is becoming mandatory to
switch to alternative sources for energy. In this paper an attempt has been made to use non
conventional energy sources at the domestic level that supplements the regular power supply.
The houses are trifurcated into low, middle and high income groups based on energy
consumption. Solar and wind energies are considered as they are available in plenty in most
of the regions in India, and can be installed easily at the consumer’s premises.
Key words: renewable energy, photo voltaic energy, wind energy, Micro Power Generation
1. INTRODUCTION
India stands fifth in the world with respect to energy consumption with an installed
capacity of about 210.936GW [1]. This is still far behind relative to the developed countries
around the globe. The demand/supply gap is around 8.2% in India [2], which is hampering
the growth of industrial sector and becoming an impediment to the progress of economy.
India heavily depends on the import of fossil fuels like coal, oil and gas which results in
heavy loss of foreign exchange. These sources are fast depleting and hence the prices are
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2. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
shooting up affecting the country’s economy adversely. Hence it is essential to vet alternate
energy technologies to tackle the energy crisis. Kennedy et al [4] gave a generic approach to
calculate long term costs and benefits of renewable energy generation. However this limits to
impact on two different units rather than system as a whole. Bergmann et al [5] estimated the
costs of renewable technologies and no approach was made to quantify the costs G. Young et al
[6] indicated that photovoltaic generation is cost effective if we wish to power a home which is
more than 2 miles from nearest power line. This literature survey prompted the authors to think
about effective generation for domestic applications using renewable energy sources. The Indian
Renewable Energy Program is well established under the Ministry of New and Renewable
Energy (MNRE) [3] which is promoting R&D, demonstration projects, subsidy programs etc. in
the area of renewable energy sources along with Indian Renewable Energy Development Agency
(IREDA).
The key factors that force usage of renewable energy are:
• Demand- supply gap
• Economic and environment and energy security concerns
• Huge untapped potential of renewable energy and reducing cost of generation
• Feasibility particularly for domestic and rural electrification
This paper addresses the need for usage of available renewable energy sources at the
domestic level and associated savings achieved.
2. MICRO GENERATION
Micro generation refers to the production of low carbon electrical power by domestic
consumers to meet their own requirements. Micro generation technologies include solar based
photovoltaic systems and small wind turbines which can be installed easily at the premises of the
consumer to supplement the regular grid supply.
3. FOCUS ON SOLAR AND WIND ENERGY
India receives a good amount of solar radiation as it is located between the equator and
tropic of cancer in the Northern hemisphere. The daily incident solar energy ranges from 4 to 7
kWh/m2 based on location with about 1500 to 2000 sunshine hours per year [7]. Wind energy
depends indirectly on solar radiation as the circulation of air is caused by non uniform heating of
earth’s surface.
4. PROBLEM FORMULATION
In the present paper a case study is presented to exploit and effectively utilize the
renewable energy sources at domestic level to reduce the energy demand from grid, which in turn
minimizes the adverse environmental impact. The houses are classified into three types namely
lower class(class A), middle class(class B) and higher class( class C) taking the average
consumption into account and load tables are prepared which are shown in Appendix A. The
hours of usage is estimated based on the sample survey on one feeder in Visakhapatnam. The
monthly and hourly solar and wind energy data is also shown in appendix B which is taken from
[8]. Depending on month and time the consumer should connect his loads to the available solar
panel and/or wind generator and remaining loads will be connected to the grid. The bill has been
calculated when loads are connected to renewable energy sources (solar and wind). The bill when
loads are connected to renewable energy sources is savings obtained in the month. The savings
are calculated for the three classes individually.
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3. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
Appendix A
CLASS WISE LOAD TABLES
CLASS A
TIME LABLE WATTAGE MONTH
18-22 L1 40 1-12
18-24 F1 60 1-12
1-6 F1 60 1-12
10-12 TV 100 1-12
17-21 TV 100 1-12
18-24 BL1 10 1-12
1-6 BL1 10 1-12
18-21 L2 40 1-12
18-22 L3 40 1-12
CLASS B
ROOM TIME LABLE WATTAGE MONTH
Bed room 18-21 L1 40 1-12
18-24,1-6 F1 60 1-12
22-24,1-6 BL1 10 1-12
Hall 10-13,16-22 TV 100 1-12
10-13,16-22 F2 60 1-12
18-22 L2 40 1-12
Kitchen 6-9,12-13,18-21 L3 40 1-12
8-9,12-13,20-21 F3 60 1-12
7-8 MIX 450 1-12
Motor 6-7,16-17 M 750 1-12
Bath Room 6-8,18-22 L4 40 1-12
Surroundings 18-22 L5 40 1-12
22-24,1-6 BL2 10 1-12
CLASS C
ROOM TIME LABLE WATTAGE MONTH
Bed Room1 18-21 L1 40 1-12
18-22 L2 40 1-12
18-24.1-6 F1 60 1-12
18-24,1-6 BL1 10 1-12
Bed Room2 18-22 L3 40 1-12
18-24,1-6 F3 60 1-12
14-15,20-24 AC1 2400 1-12
1-4 AC1 2400 1-12
18-24,1-6 BL2 10 1-12
Verandah 18-24,1-6 L4 40 1-12
Guest Room 16-21 F4 60 1-12
16-21 L5 40 1-12
18-21 L6 40 1-12
Hall 10-13,16-22 F5 60 1-12
18-22 L7 40 1-12
18-22 L8 40 1-12
12-14,18-22 TV 100 1-12
Kitchen 8-9,20-22 F6 60 1-12
7-8,18-22 L9 40 1-12
7-8 MIX 450 1-12
1-24 Fr 1000 1-12
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4. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
Appendix B
WIND TABLE
Month Jan Feb March Apr May June July Aug Sep Oct Nov Dec
Wattage/Hour 207 230 227 165 348 563 668 461 358 185 282 340
SUN TABLE: Wattage available
Month/Time 6 7 8 9 10 11 12 13 14 15 16 17 18
January 0 25 75 225 300 350 400 375 350 275 125 25 0
February 0 25 75 225 300 350 400 375 350 275 125 25 0
March 0 25 75 225 300 350 400 375 350 275 125 25 0
April 25 50 125 275 375 450 500 450 400 350 250 100 25
May 25 50 125 275 375 450 500 450 400 350 250 100 25
June 25 50 125 275 375 450 500 450 400 350 250 100 25
July 0 25 75 225 300 350 400 375 350 275 125 25 0
August 0 25 75 225 300 350 400 375 350 275 125 25 0
September 0 25 75 225 300 350 400 375 350 275 125 25 0
October 0 15 25 75 150 250 350 300 250 200 100 50 0
November 0 15 25 75 150 250 350 300 250 200 100 50 0
December 0 15 25 75 150 250 350 300 250 200 100 50 0
UNIT COST TABLE
Units per month Unit cost
(Rs)
0-50 1.45
51-100 2.80
101-200 3.60
201-300 5.75
301-500 6.75
>500 7.25
The algorithm for proposed method:
1. Input choice of Class of Load.
2. Input Load data, Wind energy data, solar energy data and cost per unit.
3. Calculate Gi= Wi + Si
Where Gi = Renewable energy generation at ith hour,
Wi = Wind energy generation at ith hour,
Si = Solar energy generation at ith hour.
4. If Li < Gi , Energy saving is Li kwh.
Where Li = Load at ith hour.
5. Calculate Cost of Energy saving
Ci = Li * (Cost/unit)
Where Ci = Cost of Energy saving at ith hour.
6. If Gi < Li , Energy saving is Gi kwh.
7. Calculate Cost of Energy saving
Ci = Gi * (Cost/unit).
8. Plot graph for Load curve, Energy savings in Kwh and Cost of Energy savings in Rs.
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5. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
5. RESULTS
A software has been developed using MATLAB for calculating the savings obtained
by use of renewable energy sources in a given month. The load curves are plotted based on
the classification of houses. Table 1 gives the energy savings estimated with the use of
renewable energy. Graphs are also plotted for every month with respect to savings in KWH
and saving in INR for each classification. Figure 1, 2 and 3 presents the typical load curve,
energy and cost savings of class A, B and C houses respectively. The accuracy of the
estimation solely depends on the data assumed and hence the method is highly flexible and
can be tailored to suit any local conditions.
Table 1: Energy savings with renewable generation
Type of Energy Energy % Energy Cost saving
House consumption generated by Saving
per year renewable
(KWH) sources (INR)
(KWH)
Class A 686.2 645.8470 94.11 1010.2
Class B 1974.7 1392.9 70.53 3276.4
Class C 18721 3873.5 20.69 20032
Figure 1: Load and saving of Class A house
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6. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
Figure 2: Load and saving of Class B house
Figure 3: Load and saving of Class C house
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7. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –
6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 1, January- February (2013), © IAEME
6. CONCLUSION
It is observed that the percentage energy savings with the available solar and wind
powers is 94.11, 70.53 and 20.69 in the case of Class A, class B and Class C houses
respectively. The authors feel that by shifting partially to renewable energy sources will make
India to attract foreign investments to herald green energy revolution in India.
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5. Bergmann, A., Hanley, N., Wright, R., 2006. Valuing the attributes of renewable
energy investments. Energy Policy 34, 1004–1014.
6. G.Young et.al “Cost effectiveness of photovoltaics” renewable electricity solutions.
www. Renewable electricity.com
7. Solar power in India: Wikipedia
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