Energy storage systems made mandatory for solar projects in Tamil Nadu
The advisory, addressed at state power utilities and Renewable Energy Implementing Agencies (REIAs), recommends that future solar projects incorporate at least a two-hour co-located BESS with a capacity equivalent to 10% of the installed solar generation.
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CHENNAI: Integrate battery energy storage systems (BESS) with upcoming solar power projects, particularly rooftop solar (RTS), the Central Electricity Authority has mandated. In a directive, the CEA said the move will enhance grid stability, optimise energy utilisation, and support India’s target of achieving 500 GW of non-fossil fuel capacity by 2030.
The advisory, addressed at state power utilities and Renewable Energy Implementing Agencies (REIAs), recommends that future solar projects incorporate at least a two-hour co-located BESS with a capacity equivalent to 10% of the installed solar generation. Also, the distribution licensees should consider mandatory two-hour storage requirements for rooftop solar projects. This could enhance power reliability for consumers while preventing the over-injection of electricity into the grid during peak solar generation periods.
Renewable Energy Producers’ Association (REPA) chairman K Venkatachalam said battery storage for solar generation will be financially viable only if the cost is reasonable. “The cost of a one-kilowatt Lithium Ion battery in China is $63. The same will cost $157 in India, thanks to high import duty. For a mega-watt scale battery, it will cost Rs 53-60 lakh while in India it will be Rs 1.55 crore,” he said, adding the government should reduce the import duty to bring the battery cost on par with the international market. On the battery storage for the rooftop solar, he said that generation from rooftop solar plants matches the consumption.
India has set an ambitious target of achieving 500 gigawatts (GW) of non-fossil fuel energy capacity by 2030. However, the variability of solar and wind power presents challenges to grid stability.
India has an installed energy storage capacity of 4.86 GW, comprising 4.75 GW of Pumped Storage Projects (PSP) and 0.11 GW of BESS. To support the integration of an anticipated 364 GW of solar and 121 GW of wind power by 2031-32, the country would require an estimated 73.93 GW of ESS capacity, the advisory said.
The advisory highlights that implementing the proposed storage clause could lead to approximately 14 GW/28 GWh of storage by 2030. With battery costs declining, integrating BESS with solar projects could also reduce power purchase expenses during evening hours when solar generation is not an option.
The advisory outlines two potential operational models for BESS: single-cycle operation, where energy is stored during peak solar hours and discharged in the evening, and double-cycle operation, where the system can also be charged using off-peak grid electricity and discharged during peak demand periods.
