Rooftop solar panels are changing the skyline, with quite a few Chennaiites keen to become self-sufficient for energy. Hema Vijay speaks to some home-owners

While the trend of installing rooftop solar panels is gradually catching up in Chennai, an enthusiastic bunch of residents has gone a step further. They not only generate solar energy to power their homes, but also supply surplus power to the Tamil Nadu Electricity Board (TNEB). Take, for instance, 79-year-old V. Balakrishnan, a resident of Kalakshetra Colony, Besant Nagar, who strongly believes that solar is the way to go. “Though it’s a matter of time, the city will switch to solar and also supply electricity to the TNEB. If the State does not rely on external sources, it will save on transmission costs,” he says. Balakrishnan has installed a 10x12 feet split solar panel with a capacity of 1.5KW that generates six kilowatt hours (six units a day). The two-way net electricity meter reads both incoming and outgoing electricity. “The months I generate surplus energy I need not pay the electricity bill, which now seldom exceeds Rs. 400. Earlier, it invariably crossed Rs. 2,000,” he says. His 3KW inverter has the capacity to support another 1.5KW panel and Balakrishnan is all set to double production by installing additional solar panels. “Since my system generates 6 units per day, I can recover the Rs. 1.2 lakh I spent on my solar power system in around six years,” he says.

So, what are the advantages of passing on electricity to the grid instead of storing it in batteries? Balakrishnan explains, “With this system, one does not need expensive batteries, and can avoid any loss of electricity through discharge. The days my system generates more electricity than what is needed, it is banked as an electricity credit with the state electricity board, and results in earnings.”

The concept is gaining popularity, says Jitendar Bagmar of Creative Solutions. A channel partner of Sukam Power Systems, the company has installed solar panels in eight homes in the city. “Residents are showing a great interest in solar after the announcement of a Rs. 20,000 subsidy last year as part of the chief minister’s scheme for residential rooftop solar power generation. We have installed panels on homes in Madipakkam, Boat Club Road, Thiruvanmiyur, Purasawalkam and IPS Colony. The subsidy is in addition to the Rs. 30,000 offered by the Central government, so residents effectively get a Rs. 50,000 subsidy when they opt for a rooftop solar power system.”

When Suresh Jayachandran of Madipakkam heard about the subsidy, he opted for solar instead of the inverter he had originally planned. He says, “A regular inverter would have cost Rs. 16,000, while the 1KW solar power system cost Rs. 52,000. “This was a great move, as my bills have become lesser by at least 100 units per cycle.”

K. Akila of Triplicane too has opted for a 1KW system that cost her Rs. 48,000, inclusive of the net meter obtained from TNEB. She says her system generates 4-5 units a day, or around 220 to 240 units every two months (or a single cycle) “Compared to my earlier electricity bills of Rs. 4, 000-Rs. 5, 000, I shell out only Rs. 1,000 now.”

Sandeep. R, an advocate based in Purasawalkam, switched to solar as he was looking for an eco-friendly power backup system and wanted to replace his diesel generator at home. He installed a 1KW solar power system two months ago and has applied for the net electricity meter. “The entire system, including the meter, cost around Rs. 73,000 and I have already started saving over Rs. 1,000 on my bi-monthly bill. By generating electricity, I have also started coming under the stipulated ‘500 unit’ slab, which has substantially lowered my per-unit cost as charged by TNEB,” says Sandeep.

A 1KW system that generates about 3.5 to 4.5 units a day requires around 100 sq. ft of roof space, and people can opt for panels that suit their energy needs and space availability. The basic maintenance is quite simple — you just need to wipe the panels with a wet cloth in the morning or late evening once a fortnight. Though, like Suresh, you could just use a dry mopping stick to reach up to the top surface of the panels and dust them. And if you are wondering what happens when workmen take up repair work on the electricity cables, well, an auto cut-off system in the inverter instantly cuts off outgoing electricity transmission from the inverter, averting any chance of an accident.

It is advised to buy solar power systems from authorised agencies recognised by the state electricity board, to ensure compatibility of the system with the state grid. Recognised dealers also handle installation.