The deficit also follows delays, a government source said, in the commissioning of 3.6 gigawatts (GW) of new coal-fired plants which had been targeted to be operational before March.
A peak shortage of 14 GW is forecast in June during nighttime hours, when solar capacity is offline, the Central Electricity Authority, the country's planning body for the power sector, told Reuters in a statement.
"The planning process relies on worst-case scenarios," it said.
The gap is the widest since 2009-10, according to publicly available government data. India's hydroelectricity output fell at the steepest pace in four decades in the year ended March 31, while renewable energy generation was flat.
Reuters Graphics
Power Minister R K Singh held an emergency meeting last week to take stock of the situation, and decided to defer shutting down power plants for planned maintenance during June and revive 5 GW of idled coal plant capacity, two separate government sources present in the meeting said.
"All efforts have been made to maximise generation, and with the measures in place it is expected that the power demand would be adequately met during the day and the non-solar hours in the coming months including June 2024," the statement said.
Grid administrator Grid-India projects maximum night-time demand of 235 GW in June, the statement said. On the supply side, nearly 187 GW of thermal capacity is available, and about 34 GW from renewable sources, according to government sources.
The figures on power demand and capacity projections have not been previously reported.
The power ministry last month invoked emergency rights for the first time to direct gas-based and imported coal-based power plants to operate at full capacity.
