India to Test Battery Storage at Coal Plants to Balance Solar and Strengthen Grid

India has launched trials to integrate large-scale battery storage systems at coal-fired power plants, a move designed to absorb surplus solar power, lower grid costs, and ensure electricity reliability as the country accelerates its energy transition.

The National Thermal Power Corporation (NTPC), the country’s largest thermal power producer, is spearheading the pilot projects with support from the central government. The batteries will be installed at select coal stations to capture excess solar generation during daytime lulls in demand and release it during evening peaks, when electricity use climbs and solar output fades.

The initiative comes as India’s rapid solar expansion places new strains on its conventional power system. Coal plants are increasingly forced to ramp down or halt operations when solar generation floods the grid, a process that thermal units are not designed to handle efficiently. The result is higher fuel consumption, steeper costs, and faster equipment wear, alongside risks to grid stability once the sun sets.

The Central Electricity Authority has acknowledged these challenges and issued new operational guidelines for coal units in a renewables-heavy environment. Battery storage is now being viewed as a potential stabiliser, or 'shock absorber,' to allow coal plants to run more smoothly while maximising renewable integration.

NTPC’s programme is India’s first significant attempt to test coal-linked batteries at scale. The systems are expected to reduce fuel waste, extend plant lifespans, and provide a steadier flow of power to the national grid. Reflecting the seriousness of the plan, NTPC has already invited bids for 1.7 GW of battery storage capacity across 11 coal stations.

At the same time, India’s energy storage market is evolving quickly. Merchant battery systems, which purchase power when prices are low and sell during demand spikes, began turning a profit last year. The trend has been driven by falling battery costs and volatile electricity prices, underlining the growing commercial as well as technical importance of storage in the power sector.

According to the International Energy Agency, India’s coal capacity is likely to plateau within the next five years, while solar could climb to 800 gigawatts by 2040. By then, coal and solar may account for nearly equal shares of generation, with renewables powering most of the growth.

The success of battery trials at coal plants could help India bridge its traditional energy backbone with its renewable future. If scaled effectively, the model may offer lessons for other coal-reliant economies seeking to balance decarbonisation with reliability.