India’s power sector is increasingly facing a non-solar-hour crisis, with rising evening shortages, solar power wastage and inadequate storage infrastructure exposing deep stress in the electricity grid even as renewable energy capacity expands rapidly, according to a Citi Research report and grid data.
The report said the country’s electricity challenge is no longer merely about generating enough power, but about ensuring reliable supply after sunset when solar generation disappears and cooling demand remains elevated.
“The challenge is shifting from ‘not enough energy’ to ‘not enough dispatchable energy at the right hour’,” Citi said.
India’s non-solar demand met has already crossed 230 GW, requiring thermal power stations to ramp up aggressively during evening hours to maintain grid stability.
Surge in electricity demand
The stress comes at a time when India’s peak electricity demand has surged from around 119 GW in 2010 to nearly 250 GW in 2025. The Central Electricity Authority (CEA) expects peak demand to touch 270 GW during 2026.
Despite rapid solar additions, grid operators are increasingly being forced to curtail renewable generation due to transmission bottlenecks, weak storage deployment and operational inflexibility in the power system.
Even as India’s electricity demand touched a record high in April amid an early summer heatwave, around 23 gigawatt-hours (GWh) of solar power was curtailed every day on average.
What does data posted by Grid India suggest?
According to Grid India data, at least 693.81 GWh of solar power was curtailed in April alone, around 74% higher than the combined curtailment recorded during January-March. On April 5 alone, solar curtailment touched 80.5 GWh.
Curtailment refers to the forced reduction or shutdown of available renewable power generation despite plants being capable of producing electricity. It typically happens when the grid is unable to absorb excess renewable energy because of transmission bottlenecks, low demand during solar hours or inadequate storage capacity.
The report also highlighted widening divergence in electricity prices between daytime and night-time hours.
Spot prices on the Indian Energy Exchange repeatedly hit the regulatory ceiling of Rs 10 per unit during night-time hours in April before crashing to nearly Rs 1.5 per unit during the day due to excess solar supply, reflecting growing imbalance between abundant daytime renewable generation and tighter evening supply conditions.
Citi said that India’s current grid architecture is increasingly struggling to absorb rising renewable energy generation.
The brokerage estimated that India would require nearly Rs 7.3 trillion of transmission and distribution investments between FY27 and FY36 to strengthen transmission corridors, build grid flexibility and integrate renewable energy capacity.
According to Citi, India is now entering its “first-ever multi-vector capex upcycle” spanning thermal generation, transmission, storage, nuclear and renewable energy infrastructure.
The report said multiple instances of solar power curtailment between May and December 2025 had already exposed operational challenges in integrating large-scale renewable energy into a thermal-heavy grid.
To address the growing after-sunset challenge, India is expected to witness massive investments in battery and pumped hydro storage systems.
CEA projections cited by Citi estimate battery energy storage system (BESS) requirements rising sharply from 6 GW in 2026-27 to 80 GW by 2035-36, while pumped hydro storage capacity may rise from 5 GW to 94 GW during the same period.
Coal-fired generation, despite the clean energy transition, will continue to remain critical for grid reliability and non-solar-hour supply management, the report said.
Around 97 GW of coal-based capacity is either under construction or in planning stages by the early-to-mid 2030s.
At the same time, renewable energy capacity is projected to surge from 172 GW in FY25 to 412 GW by FY32, while solar capacity alone may rise to nearly 295 GW.
Citi also flagged growing electricity demand from data centres, electric mobility and air-conditioning as key drivers of future power consumption growth.