Structural and operational factors of renewable energy curtailment in India in 2025

This report examines the structural and operational drivers of renewable energy curtailment in India in 2025, highlighting the roles of demand forecasting errors, limited system flexibility, and transmission bottlenecks. It distinguishes between emergency curtailment via Tertiary Reserve Ancillary Services (TRAS) and structural curtailment caused by inadequate transmission infrastructure, particularly affecting projects under the temporary general network access (T-GNA) framework.

• By December 2025, India's non-fossil fuel-based power capacity reached 266.7 GW, with solar accounting for 135.8 GW (26% of total installed capacity) and non-fossil sources overall representing 52%.
• Under the Indian Electricity Grid Code (IEGC) 2010, renewable energy has 'must-run' status, meaning load dispatch centres are statutorily responsible for evacuating all available solar and wind generation, except for reasons of grid security or safety.
• Emergency curtailment is managed through Tertiary Reserve Ancillary Services (TRAS), operated by the National Load Dispatch Centre (NLDC) to maintain grid stability during infrastructure outages or demand forecasting errors. For ISTS-connected solar projects, this resulted in curtailments of approximately 45 GWh on 25 May 2025 and 93.3 GWh on 12 October 2025.
• The primary structural cause of curtailment is the mismatch between rapid renewable energy deployment and slower transmission infrastructure construction. Projects with temporary general network access (T-GNA) are particularly vulnerable; in December 2025, approximately 4 GW of solar capacity under T-GNA faced complete curtailment on some days between 11 a.m. and 2 p.m.

APA

Ember (2026). Structural and operational factors of renewable energy curtailment in India in 2025. https://ember-energy.org/chapter/structural-and-operational-factors-of-renewable-energy-curtailment-in-india-in-2025/

Chicago

Ember. Structural and operational factors of renewable energy curtailment in India in 2025. 2026. https://ember-energy.org/chapter/structural-and-operational-factors-of-renewable-energy-curtailment-in-india-in-2025/.

Wikipedia

{{cite report |author=Ember |title=Structural and operational factors of renewable energy curtailment in India in 2025 |date=27 January 2026 |url=https://ember-energy.org/chapter/structural-and-operational-factors-of-renewable-energy-curtailment-in-india-in-2025/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{ember2026structural, author = {{Ember}}, title = {{Structural and operational factors of renewable energy curtailment in India in 2025}}, institution = {Ember}, year = {2026}, month = jan, url = {https://ember-energy.org/chapter/structural-and-operational-factors-of-renewable-energy-curtailment-in-india-in-2025/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }