India curtailed about 2.3 TWh of solar power between May and December 2025 due to grid security concerns, says Ember
October alone accounted for 0.9 TWh, highlighting limits in system flexibility
Solar capacity grew by 38 GW in 2025, but lower-than-expected demand and the coal fleet’s limited ability to ramp down led to daytime oversupply
The system missed out on around 2.11 million tonnes of potential CO₂ emissions reductions owing to the curtailment
Between May and December 2025, India curtailed an estimated 2.3 TWh of solar power, including 0.9 TWh in October alone, due to grid security concerns. According to a new Ember report, the need for greater system flexibility is evident, as a lack of it could limit further solar integration.
Last year, Ember says, India’s installed solar capacity expanded by 38 GW. Rising solar generation led to daytime oversupply; however, demand was lower than expected. The coal fleet was unable to reduce its output enough due to technical limits. To keep the grid stable and safe, some solar power had to be switched off, according to the analysts.
Additionally, although renewable energy generators would receive around INR 5,750 million–INR 6,900 million in compensation for curtailment, the power system still lost an estimated 2.11 million tonnes of unrealized CO₂ abatement, the global energy markets think tank points out.
“While grid security-related curtailment in 2025 may not be a major concern in isolation, as it was largely triggered by lower-than-expected demand, it served as a real-world stress test for a high-solar future,” said Ember Energy Analyst Ruchita Shah. “It highlighted a fundamental reality: clean energy cannot scale efficiently without flexibility.”
In the absence of flexibility, such curtailment could become ‘routine’ as has been the experience of some international markets. To avoid this, Ember recommends that India expand its flexibility tools at the same pace as solar capacity growth.
“The extent of avoided curtailment in the future will depend on how accurately demand is forecasted, how decisively India resolves transmission bottlenecks and how rapidly it scales flexibility resources,” recommends the energy think tank.
Ember’s report titled Beyond capacity: why India’s power system must get flexible to harness its solar potential is available for free download on its website.
TaiyangNews is bringing together the Indian solar PV manufacturing industry at the Solar Technology Conference India 2026 (STC.I 2026) on February 5 and 6 in Aerocity, New Delhi. This 2nd edition of the TaiyangNews physical conference will also have banks, investors, and policymakers in attendance. Register for the event here.