India is meeting new energy peaks during the day this summer, but come sundown, power shortages are becoming more frequent.

Consider this: On May 19, 2026, at 3.40 PM, energy demand surged to a new high of 260.45 GW and was met with no shortage. Coal-based thermal power contributed the most to meeting demand, at over 162 GW. Renewables followed with 74 GW (solar 57 GW and wind 17 GW), with hydroelectric and nuclear making up the rest.

The morning trough was at 216 GW at 7 AM, indicating a 44 GW swing in demand during the day.  For the first time, non-solar hour peak crossed the 250 GW-mark at 10.38 PM when the energy demand soared to 251.54 GW.

The day’s energy peak preceded similarly high energy demand days when India’s electricity system met 250 GW plus without a sweat. An intense heat wave, which started earlier than expected, is contributing to higher cooling demand and the consequent rise in energy peaks.

It is a different story altogether when the sun stops shining. On May 19, the non-solar hour shortage was 698 MW. On May 18, 257 GW plus was the demand met at around the same time in the afternoon. However, the non-solar hour shortage was 1.3 GW. Two days earlier, the non-solar hour shortage was slightly short of 800 MW.

On April 24, the non-solar deficit was as high as 5.4 GW. The solar hour demand reached 252 GW that day.  The next day was only slightly better, with the shortage dropping to 4.2 GW, while the solar hour demand of over 256 GW was met.

These figures suggest that India’s challenge is not generation during the day. The problem is in shifting surplus solar power into the non-solar hour peak. The grid’s vulnerability is shifting toward the hours after sunset, underscoring the urgent need to augment battery energy and pumped storage capacity.

New demand from upcoming data centers and AI is likely to further increase pressure on the grid. The Central Electricity Authority has projected that peak demand will grow from 289 GW in 2026-27 to 459 GW by 2035-36.

India added nearly 547 MWh of battery energy storage capacity in 2025, around 26% year-over-year increase from over 433 MWh, according to the 2H & Annual 2025 India’s Energy Storage Landscape Report by Mercom India Research. India’s cumulative installed battery energy storage capacity reached almost 1,082 MWh as of December 2025. The cumulative installed capacity of pumped storage projects stood at around 7 GW, of which almost 6 GW is operational.

While operational energy storage capacity has not yet reached significant levels, installations are likely to grow substantially as tender volumes rise.

According to Raj Prabhu, CEO at Mercom Capital Group, energy storage is expected to play a critical role in India’s clean energy future, helping maintain grid reliability, enabling flexibility, and ensuring stability as renewable penetration continues to rise.