Energy storage the answer to solar boom stress on power grid, says new study
Times of India | 17 July 2026
Kolkata: India’s rapid expansion of solar power has ushered in a new challenge for the country’s electricity grid, with the focus shifting from generating enough electricity to ensuring that power is available at the right time and can respond quickly to fluctuations in demand, says a new research paper by economist Sanjeev Sanyal, a member of the Prime Minister’s Economic Advisory Council.
The paper, “The Duck and The Camel: Tracing the Net Load on the Indian Power Grid”, co-authored by Sanyal and Satvik Dev, argues that rising solar penetration is creating significant operational stress on the national grid.
While solar power is successfully meeting a large share of daytime electricity demand, it is simultaneously forcing conventional sources — particularly coal-fired thermal plants — to ramp down generation sharply during the day and then rapidly increase generation after sunset to meet the evening demand.
The paper describes this phenomenon through the summer “duck curve” and winter “camel curve”, both of which illustrate steep swings in net electricity demand that grid operators must manage every day.
The report, submitted to the Union power ministry, identifies energy storage as the most effective solution to this growing imbalance. “The most direct remedy is to store energy when it is abundant and release it when it is scarce, complemented on the demand side by time-of-day tariffs and demand response that move load toward the solar hours. The gap between need and provision of storage is the greatest, and it is overwhelmingly a battery gap,” the paper states.
According to the paper, three indicators highlight the increasing stress on the grid. The first is the sharp divergence in electricity prices. During May 2026, power traded on the Indian Energy Exchange (IEX) day-ahead market averaged just Rs 1.1 per unit during midday, when solar generation was at its peak, but surged to Rs 9.7 per unit at night, when solar output disappeared.
The second signal is renewable energy curtailment. Around 24 gigawatt-hours (GWh) of solar electricity was curtailed every day in May, effectively wasting clean energy that, according to the report, could have powered more than one-quarter of Delhi’s daily electricity requirement.
The third indicator is growing supply shortages outside solar hours. During April and May, the grid recorded 36 days of shortages during non-solar-hour peak demand, compared with only six days of shortages during solar-hour peaks.
Arguing that India’s power sector has crossed an important threshold, the paper says the “binding constraint has shifted from capacity to flexibility”. While supporting the direction of the Draft Electricity (Amendment) Bill, 2025, and the draft Electricity (Rights of Consumers) Amendment Rules, 2026, the authors caution that rapid solar expansion without corresponding investments in storage and flexible grid management could intensify operational stress.
Solar energy expert Avijit Ghosh said battery storage and pumped-storage hydropower would be critical for maintaining grid stability as renewable energy capacity grows.