At the Magnolia block of Brigade Millenium apartments in J.P. Nagar, 142 solar panels with a capacity of 350 watts were installed in 2019 at a cost of ₹32.5 lakh. Around 90% of power requirement of the common area of the apartment is catered to by the panels generating more than 70,000 units a year.
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“We have saved ₹19.5 lakh over three years, and also saved 72 tonnes of carbon emissions. There were a few initial challenges like selection of panels and vendors, employing the right design, placement of inverter and assessing space and structural requirements. Once all of that was sorted out, we have been recovering an average of ₹6.5 lakh of our capital cost every year,” the residents said
Green energy path
In the last few years, many residential complexes in Bengaluru decided to choose the green energy path, and installed rooftop solar panels on their terraces. Even with the 50-kW limit granted by Bangalore Electricity Supply Company (Bescom), these complexes say they have been saving in lakhs for power bills every year on their energy expenses with a one time investment on panels.
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At Brigade Millenium apartments, while a total of 74,660 units of solar energy were generated in the first year, despite erratic rain patterns, in 2020–21 and 2021–22, the panels generated 70,320 units and 70,900 units respectively. The residents also pointed out that 28 degrees celsius is the optimum temperature for solar power generation and anything more or less will affect energy generation.
“Even if it rains in the night, a little sunlight in the morning will enable generation of power, which is why it (generation) has not been affected by rains. February–April is the optimum time for solar power generation,” said Subramanya Putrevu, a resident of Jacaranda block at the same apartment.
In the last few years, many government and private buildings have installed rooftop solar panels. According to data provided by Bescom, during the year 2022 – 23 (until November), 131.47 units of energy were generated out of which, private buildings generated the major share of 128.63 units while government buildings generated just 2.84 units.
‘Remove ceiling’
Residential complexes are now demanding that the 50 kW wattage limit on Low Tension (LT) panels should be removed by Bescom and that they should be allowed to generate energy as much as their requirement is. They also said that easing of the process of application and implementation will encourage more such complexes to opt for rooftop solar panels. “Like how they have made rainwater harvesting and sewage treatment plants mandatory now, the same way they should make solar power panels mandatory for all the residential buildings,” another resident said.
Bescom officials said that they are working on increasing the 50 kW limit given to residential buildings. “That decision will be made by Karnataka Electricity Regulatory Commission (KERC). We have also advised them (residential buildings) to file a petition with the KERC and when objections are raised, we will give our comments in a positive manner,” said Mahantesh Bilagi, Managing Director, Bescom.