Battery storage capacity must keep pace with solar energy generation

Battery storage capacity must keep pace with solar energy generation

India scaled a record peak demand of 256.1 GW on April 25 with solar plants supplying 21.5% of the afternoon load — an all-time high, and the clearest signal yet that the country’s installed solar fleet can do real work when the sun is overhead. But the same day’s full 24-hour ledger told a more sobering story. When there was accounting for the whole day of April 25, solar contributed only about 10.8% of daily generation, and just 0.1% of the evening’s needs after sunset. Solar’s share of India’s installed electric capacity has nearly doubled from about 15% in 2022 to nearly 28% in early 2026. However, solar accounted for roughly 5.6% of generation on India’s peak-demand day in 2022 and only increased to the 10.8% of April — a clear indication of the yawning gap that remains between the realities of the present and what is possible. The bottleneck is not panels, land or ambition but the inability to use the vast stores of generated electrons through batteries. In fact, such is the paucity of battery storage that States which are prolific producers of solar power are being asked to halt their supply, lest it compromise the stability of India’s electric grid. In 2025, India had to curtail 2.3 terawatt hours of solar generation between late May and December, equivalent to 18% of average monthly solar output, with 0.9 TWh (terra-watt hours) wasted in October alone. Given that producers of such electricity must be compensated, this ends up being a cost to the public exchequer which pays for power that was never delivered. The India Meteorological Department’s forecast of a below-normal monsoon at 92% of the Long Period Average — the first such warning in 11 years — only sharpens the argument: a hotter, drier summer means greater daytime demand, which is precisely when solar should be doing the heavy lifting.

The encouraging news is battery economics. Standalone two-hour battery storage tariffs fell from around ₹2.21 lakh per MW per month in early 2025 to ₹1.48 lakh by year-end. The challenge is execution. Only 0.7 GWh of battery storage was operational in India by end-2025, with another 2 GWh expected by December 2026. The Centre and States must now focus less on tendering and more on commissioning — pairing every fresh solar auction with mandatory co-located storage and resolving the financing wall facing aggressively bid low-tariff projects. Solar capacity without storage is a half-built bridge.