Bringing The Sun Closer To Home Team members:- ANIRUDH ROY UTKARSH SINGHAL SRIJAN KUMAR NANDINI AGNIHOTRI Delhi Public School Ghaziabad

Bringing the Sun closer to home Converting existing inverter into Solar Power Inverter

Bringing the Sun closer to home Aims and objectives of study To study the feasibility of converting existing household inverter into solar powered inverter. Hypothesis Household inverters can successfully be transformed into a solar powered inverter.

Bringing the Sun closer to home Need Statement 5-6 hours of power backup in cost effective manner especially during summers when power cut is more than 8-12 hours a day. The grid supply is generally not available from 30%- 50% of time in towns like Ghaziabad during peak summer.

Methodology Group A did extensive research and worked on The report Home Power Back Up Case study Log book Group B worked on Charts and posters Model Validation of recommendations of Group A

RESEARCH FINDINGS Home Power Back Up – A Case study We have an inverter with a backup capacity of 800 VA and a battery of 150 AH. It can run 1 fan, 7 CFLs, a 54 cm T.V and 1 computer at the same time for 2 hours (approx.). We calculated the duration of backup by the following formulae: Battery AH x Battery voltage / inverter capacity (in our case) 150AHx12V/800VA =2.25 hours (at full load) RUNNING OUR INVERTER at full load = 2.25 hours at half load= 4.5 hours We do not get 4.5hrs of back up due to power cuts of 8-12 hrs. during peak summer even on 50% load.

RESEARCH FINDINGS Contd… Compatibility of solar panels system with existing inverters –Our study revealed that solar panel system can be connected to the existing inverter with a simple charge controller. –Various vendors have the solution but none of them are marketing it aggressively. Instead they suggest double battery inverters designed by them.

RESEARCH FINDINGS Contd… COSTING We contacted a few vendors and got few the quotes. The specification: – 4 x 80 watt panel= 320 watt –Panel voltage= 12 V –Current produced= Amps –Efficiency= 90% –Net current produced= 26.67*90%=24 amps –Battery Capacity= 150 AH –Time required for charging = Battery capacity/net current produced = 150/24 or 6.25 hrs. –We are assuming that the whole installation will cost –Rs35,000/- all inclusive taking the lowest offer of Rs 30,000/- based on the quotes received

RESEARCH FINDINGS Contd… COST BENEFIT ANALYSIS Since we are not getting 2.25 hrs. back up during the peak summer and investing in 7.5 kVA Diesel Generator set is very expensive so we compared the existing Inverter with 320 watt solar panel connection vs VA Inverter with 2x150 AH battery system (known as double battery inverter) In proposed case :300AHx12V/1400VA =2.6 hrs. (at full load) Running Proposed Inverter –At full load = 2.6 hours –At half load= 5.2 hours ( Our desired requirement of 5 hrs) The comparison was done for: Option 1: 800 VA inverter with 150 AH Single battery and 32O KW Solar Panel VS Option 2: 1400 VA inverter with 2x 150 AH battery For simplicity of understanding only one time capital cost and replacement cost of battery and inverter has been considered. Power consumption, inflation, depreciation has been ignored in the calculation. The results based on analysis exhibited in Table 1 are:

Cost benefit Analysis Table 1

RESEARCH FINDINGS Contd… The comparison (Table 1) reveals that Initial Capital cost of Option 1 is more than Option 2. Thats one of the reason that people go for Option 2. On analyzing the life cycle it is clear that Option 2 Capital expenditure +Operating expenditure increase by 76% in 3 years while in option 1 it increases by only 25%. Deeper probing reveals that Option 2 total expenditure exceeds Option 1 in Year 6 i.e. Option 1 becomes profitable after Year 6 and there on. Our existing inverter cost and battery cost is not considered in the current comparison. If we consider complete fresh purchase of all the items in case of Option 1, than Option 1 will be profitable after 9 years and will cost whopping Rs 48,500/-.

Conclusion Since the initial capital investment is high, people tend to purchase either double battery inverter or 7.5 KVA DG set which is not green technology and requires high operating cost of diesel which is on rise. Since the gestation of recovery period is high i.e.- 6 years, people tend to go for Option 2. Option 1 will become more attractive as the solar panel costs falls, as it is happening in case of mobile handsets. Already the cost of solar panels have come down from Rs 150/watt to Rs 75/watt. Government provides incentives for opting for solar panels, like being done for large solar power projects. However there are strong followers of Green Power who adopt solar power inverters even against all odds like Mr. Jose George, a resident of Sector 22 Dwarka, New Delhi whose interview was published in Deccan Herald. According to him: I got a One KW solar panel installed at my place five years ago. Initially, it did burn a hole in my pocket and I was also skeptical if it would bring me any benefit but in the long run, it has. All the light-load appliances in my three-bedroom flat are run on the power generated from the solar panel; the heavy-load appliances like AC, fridge and water motor are run on the normal electricity supply, and my electricity bill has come down from Rs 5000 per month to just Rs Besides, I recovered the whole amount I had invested in the solar panel in three years. However there are strong followers of Green Power who adopt solar power inverters even against all odds like Mr. Jose George, a resident of Sector 22 Dwarka, New Delhi whose interview was published in Deccan Herald. According to him: I got a One KW solar panel installed at my place five years ago. Initially, it did burn a hole in my pocket and I was also skeptical if it would bring me any benefit but in the long run, it has. All the light-load appliances in my three-bedroom flat are run on the power generated from the solar panel; the heavy-load appliances like AC, fridge and water motor are run on the normal electricity supply, and my electricity bill has come down from Rs 5000 per month to just Rs Besides, I recovered the whole amount I had invested in the solar panel in three years.

Future Plans Further study of our option and look for alternate solar panel technologies which increase our existing battery back up in shortest possible time or at lesser upfront cost. Demo project at our school for Option 1. Writing proposals to the Government for providing incentives to consumers opting for solar panels less than 1 KW e.g in case of switching to LPG from Kerosene stoves.

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