KOLKATA: Scrapping of coal blocks by Supreme Court may have sown the fear of a power tariff rise among consumers, but it hardly makes any difference for those residing at SIRSA, the 10-storied residential apartment for officials of the Central Glass & Ceramic Research Institute (CSIR). They depend neither on thermal power nor any power utility. Thanks to grid-connected solar power panels installed on the roof, the complex generates its own power. In fact, they even supply power, albeit in small scale, to CESC.
Almost next to the sprawling Lake in south Kolkata, SIRSA on Lake Road is a green island amid the concrete jungle. The process of turning it into a self-reliant power producer began with the CSIR officials' determination to combat climate change in their own way. To begin with, the solar panels were commissioned for Rs 37.35 lakh (including a five-year maintenance contract), of which 30% was subsidized by the ministry of new and renewable energy. Within seven month, SIRSA has produced 31,536 units of power (till September 30). Around 30,328 units were consumed in-house and 1,208 units were sold to CESC.
SIRSA is a sharp contrast in a city where buildings rules are flouted at will. A Kolkata Municipal Corporation (KMC) rule specifically says that any high-rise over 15.5 (five-storied) needs to install rooftop solar panels. But the rule is confined to papers only. This is particularly shocking in a state where 97% of the power requirement depends on coal, much higher than the national average of 64%.
"We were really concerned with the soaring energy bill. Moreover, as member of a scientific community, I strongly felt that we must have a solution that would be truly green and sustainable. So, to offset the effect of incremental tariff and also to minimize environmental impact, we thought of exploring clean energy route. A solar power plant was an automatic choice. But wind and storms were issues. To store the power generated via rooftop panels in batteries was impractical. It was necessary to connect the solar power generation system to the grid. Finally, we have grid-connected solar photovoltaic power plant on the rooftop," said Avijit Ghosh, principal technical officer of CSIR who conceived the plant.
The rooftop solar plant, covering a space of around 550 square metre, is now functioning in full swing. The panels are tilted at 20 degree, matching the latitude of the city. "We entered into a power purchase agreement with CESC for next 25 years at the prevailing rate (at same rate they are selling). Thus we could save Rs 2.33 lakh till now and environmentally, we saved 52 tonne of carbon emission and 284 kilolitres of water in last seven months," said Ghosh.
The SIRSA complex, with 96 flats, seven lifts, 24-hour filtered water supply, power back-up and a guest house with adequate lighting arrangements. The average energy bill stands at Rs1.60 lakh on an average, out of which 55% are recovered from allottees as per meter-wise consumption. "Around 25% of the
total units are consumed by the guesthouse alone and 20% goes for common services like water pumps, lift services, common area lighting etc. With the installation of solar plant, we adopted energy efficient lighting system, pumps, lifts and other machineries in phases," Ghosh said.
Ghosh, a champion of sustainable solutions for energy intensive problems, has also set up a solar heater using empty 20 litre containers and simple plastic pipe connected with an insulated storage tank kitchen created with discarded objects. "Round the year, we get water of 33-37 degree celsius hot water. By using the water in cooking, we are saving 33% LPG consumption," he explained.
