In a move that cuts the annual electricity bill by 90% thereby reducing carbon footprint, a residential complex at Lokhandwala, Andheri (West), has installed 120 solar panels atop its building lessening its dependency on the electricity grid.
Installed last month at the 16-storeyed Cliff Tower apartment with 62 flats, the panels generate 30 kilowatt (kW) solar energy per hour that lights up its common areas, passage, terrace and compound lights and powers three lifts and five water pumps. An average household in Mumbai uses 2.5kW electricity every hour.
“Our monthly bill was Rs55,000. After installing this clean energy source, we save Rs50,000 every month. What we spent every month will now be spent in a year reducing our annual expenditure by 90%,” said R Sahgal, secretary, Cliff Tower.
The society has also installed a net meter system ---- a first-of-its-kind installed in the western suburbs.
“The system allows excess electricity generated by the solar panels to be sent back to the grid, which is compensated by the electricity supplier at the end of the year,” said Rishabh Tatia, director, Green Option Private Limited that installed the system manufactured by Tata Power Solar.
Tatia added that if the society generates 4,500 units of electricity per month via solar power vis-a-vis the requirement of 4,200 units, the additional 300 units will be carried over to the next month and so on.
With no maintenance fee required for 25 years, the society spent Rs 23 lakh to set up the project that will be recovered over the next four years. “The panels generate 100% solar power during 10 months of the year, but there is a 35% decrease during cloudy days in July and August,” said committee member Sushil Jain.
“With the intention to install a similar project, the neighbouring societies have been visiting us to understand the concept.”
Scientists said using renewable source of energy is the need of the hour.
“There is a lot of incentive for large commercial buildings, institutions and housing complexes to switch to solar energy. If more institutions opt for rooftop solar projects, it will have a significant impact on reducing carbon emissions for a city like Mumbai,” said Rakesh Kumar, director, National Environmental Engineering Research Institute (NEERI).
How does it work?
Solar radiation is converted directly into electricity by photovoltaic cells and the solar photovoltaic (SPV) technology works without producing any polluting byproducts. The grid and solar power runs parallel so that solar energy is evenly distributed throughout the complex.
Why should you care?
•Solar energy is free but there is a cost for building equipment required to convert solar energy into electricity or hot water
•Does not cause pollution
•Can be used in remote areas where electricity from the grid cannot be accessed
• Items such as street lights, calculators and other low-power-consuming devices can be powered
•Potential to harness solar energy as a natural resource is infinite.
•Can only be harnessed when it is daytime and sunny
•Solar collectors, panels and cells are relatively expensive to manufacture.