2025 saw significant solar curtailment to preserve system stability

In 2025, India experienced significant solar curtailment, estimated at 2.3 TWh between late May and December, primarily due to the inability of the coal fleet to ramp down sufficiently during periods of low daytime demand. This was exacerbated by weaker-than-forecast demand growth in 2025, driven by mild temperatures and increased behind-the-meter solar generation. The report highlights that while operational errors in forecasting contributed to the issue, the structural lack of flexibility in coal plants—many of which must operate above a minimum thermal load of 55%—creates a systemic challenge as solar capacity continues to grow faster than demand.

• Between late May and December 2025, the system operator is estimated to have curtailed 2.3 TWh of solar energy via emergency TRAS, with approximately 0.9 TWh occurring in October alone.
• Solar curtailment was driven by the coal fleet's limited ability to ramp down during midday hours while remaining online to meet evening demand peaks. Many central sector coal plants are mandated to maintain a minimum thermal load (MTL) of 55%, and over 40% of coal capacity may not be under the National Load Despatch Centre (NLDC) purview for ancillary services.
• Actual electricity demand growth in 2025 was less than 20 TWh, significantly lower than the 6% increase projected for FY 2025–26. This stagnation was caused by exceptionally mild temperatures reducing cooling needs and the growth of behind-the-meter solar generation.
• In October 2025, the reduction in average demand at 1 p.m. (14 GW or 7.2%) was double the reduction seen at 6 p.m. (7 GW or 3.5%), which increased the net load spread and the flexibility required from the system.

APA

Ember (2026). 2025 saw significant solar curtailment to preserve system stability. https://ember-energy.org/chapter/2025-saw-significant-solar-curtailment-to-preserve-system-stability/

Chicago

Ember. 2025 saw significant solar curtailment to preserve system stability. 2026. https://ember-energy.org/chapter/2025-saw-significant-solar-curtailment-to-preserve-system-stability/.

Wikipedia

{{cite report |author=Ember |title=2025 saw significant solar curtailment to preserve system stability |date=27 January 2026 |url=https://ember-energy.org/chapter/2025-saw-significant-solar-curtailment-to-preserve-system-stability/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{ember20262025, author = {{Ember}}, title = {{2025 saw significant solar curtailment to preserve system stability}}, institution = {Ember}, year = {2026}, month = jan, url = {https://ember-energy.org/chapter/2025-saw-significant-solar-curtailment-to-preserve-system-stability/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }