Why India's growing solar surplus is going unused despite record demand

India's solar generation has surged to record levels, but an average 24 GWh of electricity went unused every day in May 2026 because the grid could not absorb it before demand shifted to the evening

India's clean energy push is creating an unexpected problem. Even as solar power capacity touches record highs, a growing amount of electricity generated during the day is going unused because the grid cannot absorb or store it for use after sunset.

 

A working paper by the Economic Advisory Council to the Prime Minister (EAC-PM), co-authored by economist Sanjeev Sanyal and IRS officer Satvik Dev, said solar generation that the grid could not absorb averaged 24 GWh per day in May 2026 was equivalent to more than one-quarter of Delhi's average daily electricity consumption.

 

The paper said India is "not running short of electricity in the middle of the day". Instead, "the stress on the grid emerges when the sun is not shining. And the stress is increasing every year".

Solar capacity rises as daytime surplus grows

According to NITI Aayog's India Climate and Energy Dashboard, the country's renewable energy capacity has increased from 58 GW in 2020-21 to 283 GW by May 2026-27, with solar alone contributing 157 GW.

 

Government data also says India added 55.29 GW of non-fossil power capacity during 2025-26, the highest annual addition so far, taking non-fossil sources to about half of the country's installed power capacity.

The grid is under pressure after sunset

According to the EAC-PM paper, the challenge is no longer generating enough electricity during the day but using it when it is available. It says the country's electricity system is now constrained by "when it can generate the electricity required, and how fast it can change what it generates."

 

It added, "the active constraint for the grid has shifted from generation capacity to flexibility."

 

The paper analysed electricity demand and generation at 15-minute intervals using Grid India data.

 

It said India's grid now develops a pronounced "duck curve" during summer months, where solar generation sharply reduces the need for conventional electricity during the day before demand rises rapidly after sunset.

 

It said the imbalance has become much steeper over the past three summers.

Daytime surplus and evening demand are moving further apart

Between May 2023 and May 2026, the morning decline in net load as solar generation increases almost tripled from 18.5 GW to 52.6 GW. During the same period, the evening increase in net load almost doubled from 35.7 GW to 73.7 GW, meaning conventional power plants have to ramp up much faster once solar generation falls.

 

The paper says the midday trough in net load has barely changed despite higher electricity demand because "the extra electricity the country now draws in the middle of the day is being supplied almost entirely by the growing fleet of solar panels, leaving the conventional system with no more to do at noon than it did in 2023."

Power prices show the same imbalance

The average day-ahead market price during the midday solar peak dropped from ₹2.81 per unit in May 2023 to ₹1.11 in May 2026, while the average evening price increased from ₹8.08 to ₹9.71 per unit. The gap between the two widened from ₹5.27 to ₹8.60, indicating abundant electricity during solar hours but tighter supply after sunset.

 

Grid shortages also follow the same pattern.

 

The paper said that during April and May 2026, India recorded electricity shortages on 36 of 61 days during the evening peak, compared with just six of 61 days during solar hours.

Storage gap leaves surplus solar unused

The study said the mismatch between when solar electricity is produced and when it is needed has widened as solar capacity has grown.

 

It estimated that reducing even half of a typical summer evening ramp would require around 130 GWh of electricity discharge between 1 pm and 8 pm. By comparison, India's pumped-storage and battery fleet discharged only about 23.8 GWh across an average day in May 2026.

 

The paper said while storage is the "obvious solution", the gap is large and needs to be filled quickly.