India’s electricity grid is no longer constrained primarily by power generation capacity but by its ability to respond quickly to rapidly changing demand, making battery storage critical for maintaining grid stability, according to a report by the Economic Advisory Council to the Prime Minister (EAC-PM).
The report, titled The Duck and The Camel: Tracing the Net Load on the Indian Power Grid, said the rapid expansion of solar power has fundamentally altered the way India’s electricity system operates.
According to the report, “the best way to smoothen these fluctuations in demand and price is to store electricity when it is abundant and release it when it is scarce.”
Solar Growth Reshaping Power Demand
The study found that electricity demand is becoming increasingly uneven over the course of a day as solar generation rises sharply during daylight hours before dropping rapidly after sunset.
To assess these changes, researchers analysed the grid’s net-load curve, calculated as total electricity demand minus solar power generation, using high-frequency data recorded at 15-minute intervals.
The report examined both summer and winter demand patterns and compared monthly averages across multiple years to identify structural changes in the power system.
From the “Duck Curve” to the “Camel Curve”
According to the report, India’s net-load profile now varies significantly with the season. During summer, when air-conditioning demand is high and solar generation is at its peak, the net-load curve resembles the globally recognised “duck curve”, characterised by a deep decline in demand during the afternoon followed by a steep increase after sunset.
In winter, however, the pattern shifts to what the report describes as a “double-humped Bactrian camel”, with electricity demand peaking in the morning and evening, separated by a midday dip supported by solar generation.
Grid Challenge Has Shifted
The report said the nature of India’s electricity challenge has changed. Instead of focusing solely on adding generation capacity, the priority now is ensuring the grid can respond quickly to sharp swings in demand.
“The grid is now bound by when it can generate the electricity required, and how fast it can change what it generates. In other words, the active constraint for the grid has shifted from generation capacity to flexibility. Storage is the obvious solution. However, the storage gap is large and needs to be filled quickly,” the report stated.
Large Battery Storage Gap
The report estimated that flattening even half of the evening demand surge on a typical summer day would require around 130 GWh of battery discharge between 1 pm and 8 pm. However, India’s current storage capacity remains well below that requirement.
According to the report, the country’s combined pumped-storage and battery infrastructure discharged only about 23.8 GWh during an average day in May 2026. It noted that the shortfall is primarily due to insufficient battery storage. While the National Electricity Plan had projected 8.68 GW of grid-scale battery capacity for 2026-27, only 0.27 GW was operational as of January 2026.
Although recent additions have increased Battery Energy Storage System (BESS) capacity to 2.7 GW, the report said the gap remains substantial.
Lessons from California
The report cited California as an example of how battery storage can improve grid flexibility. According to the study, California’s battery fleet, capable of discharging more than 10 GW, stores surplus solar power during the day and supplies electricity during the evening peak.
This has reduced the state’s evening net-load swing from nearly 28 GW to around 10 GW. The report said India will require similar capabilities as renewable energy capacity, particularly solar power, continues to expand.
It concluded that large-scale deployment of battery storage alongside renewable energy projects will be essential to reduce grid stress, improve operational flexibility and support the country’s evolving power system.
