Hot and hotter. That best describes Chennai’s weather. But a few see the opportunity in this and are getting the city’s weather to work for them.

They use the free available sunlight, and heat, to generate electricity and heat to power appliances, heat water or cook food. Advantage: low electricity and fuel (cooking gas) bill.

Chennai’s Ramakrishna Mission Students’ Home, which houses 700 residents, has done just this. The Mission, which was recently awarded the highest grade of certification for green initiative by the Indian Green Building Council, has set up a solar photovoltaic system that generates around 460 units per day, which is about 90 per cent of its needs.

Swami Satyajnanananda, Secretary, Ramakrishna Mission Students’ Home, says: “We used to pay electricity bill of about ₹1.25 lakh per cycle but post installation, we are saving 80-90 per cent.”

Over 405 solar panels installed on the rooftop generate electricity. There is even some surplus production during the day and this is fed to the grid. The net metering calculates the net charge, which is paid to the utility.

Out of a total expenditure of ₹94 lakh for a 115 kW solar PV system, close to ₹82 lakh was sponsored by SunEdison, a renewable energy company, as a part of its CSR initiative two years ago.

Swami Satyajnanananda says the cost should be recovered in three years. The Home also houses a solar thermal cooking system, which has brought the monthly consumption of LPG cylinders to 20-25 from 80.

Swami Satyajnanananda says that to further reduce the LPG consumption, a bio-gas cooking system, which will generate 10 kg equivalent of LPG gas for 165 kg of wet waste, is being tested.

In recognition of its efforts to turn energy-efficient, the Home was given Platinum rating, the highest certification, by the Indian Green Building Council (IGBC).

Chandrashekhar Hariharan, Chairman – ZED Habitats, which develops green buildings, including residences and commercial space, says that in contrast to the popular belief that green buildings are expensive, they cost as much as regular buildings but are energy efficient.

Hariharan, who is a part of the IGBC, says that renewable energy can help reduce demand on the grid.