Rising Solar Penetration Puts India’s Power Grid Under Severe Stress: EAC-PM Paper Warns

New Delhi: India's power system is struggling to generate electricity at the right time, as per a new paper by the Economic Advisory Council to the Prime Minister. The paper said the defining problem for the Indian grid has shifted from capacity to flexibility, and three market signals show just how acute the mismatch between solar and non-solar hours has become.

One of the authors of EAC-PM working paper, Sanjeev Sanyal, highlighted the issue. He wrote on X, “My new EAC-PM working paper (with Satvik Dev) argues that India’s rising solar penetration is causing grid stress. While solar is meeting more midday demand, it also forces conventional sources, especially thermal plants, to ramp up and down more sharply to meet the net load. This is visible in both the summer “duck” curve and winter “camel” curve, putting grid operations under stress .”

He further wrote, “Three signals show the stress. First, prices: in May 2026, power on the IEX day-ahead market averaged Rs 1.11 per unit at midday but Rs 9.71 at night. Second, curtailment: about 24 GWh of solar was wasted daily in May. Third, shortages: the grid fell short of non-solar-hour peak demand on 36 days in April-May, compared with only 6 days for solar-hour peak demand.”

According to him, the paper supports the direction of the Draft Electricity (Amendment) Bill, 2025, and the draft Electricity (Rights of Consumers) Amendment Rules, 2026. But it cautions that without adequate storage and net-load smoothing policies, solar growth will intensify grid stress, Sanyal added.

According to the Economic Advisory Council to the Prime Minister, the intraday spread between solar hours and non-solar hours has widened to a peak-to-trough ratio approaching nine. The gap would be even wider, the report notes, but for the market's price ceiling.

In practical terms, power is plentiful and cheap in the middle of the day when solar output peaks, and turns scarce and expensive in the evening when the sun sets but demand stays high. The second signal is showing up in reliability.

The council found that the "grid's failures to meet demand rise overwhelmingly in the non-solar hours, relative to solar hours." During the day, when solar is generating, the system largely copes. The stress builds after sunset, when solar drops off sharply and the grid has too few flexible resources to ramp up quickly and fill the gap. The third signal is visible in wasted clean energy. The report says solar is being curtailed in large volumes because it cannot be consumed the moment it is produced.

The scale of the loss is significant. The paper estimates that the average daily solar curtailment in May 2026 was equivalent to the electricity that could have powered more than a quarter of Delhi for a full day.

Together, the three trends point to a grid that is flush with solar power for a few hours and then short of it for the rest. The council argues this is not a generation problem but a timing problem, and it will grow as India adds more solar. The report said addressing it will require a shift in how power is planned and distributed across the day, with greater emphasis on storing midday surplus and moving demand into solar hours. Without that, the paper warns, the price volatility, evening shortages and curtailment seen today will only intensify as the solar fleet expands.