Supporting materials

Downloads

Beyond capacity: why India’s power system must get flexible (PDF)

Methodology

Curtailment linked to delays in transmission infrastructure deployment was assessed using publicly available news articles and industry reporting documenting evacuation constraints and grid bottlenecks.

Curtailment under emergency operating conditions was estimated using Grid-India’s daily Variable Renewable Energy (VRE) reports for the period May–December 2025. Daily curtailment was converted to 15-minute solar availability using Grid-India’s hourly PSP data and Ember’s modelled estimates of hourly solar availability.

National cooling degree days were estimated using gridded ERA5 data, weighted by population.

Compensation to solar generators was estimated using prevailing market tariffs discovered through competitive bidding mechanism.

Average monthly solar generation is taken at ~13 TWh for calculating the curtailment percentage as a share of average monthly generation.

Emissions impacts were calculated using emission factor estimates from Ember – 965.64 kgCO2/MWh for coal and 48 kgCO2/MWh for solar – to estimate the emissions that could have been avoided had curtailed solar displaced coal-based generation.

To calculate equivalent households, emission of 5,625 kg CO2 per year per household was considered.

The 6% growth in demand in 2025 versus 2024 is calculated using year-on-year demand mentioned in Table 2.5 of the 20th Electric Power Survey (EPS). Expected annual generation is then distributed across months using the average annual profile from 2021-24.

Acknowledgements

Contributors

Special thanks to Tito Das and Ardhi Arsala Rahmani for communications support.

Particular thanks to Duttatreya Das, whose feedback and insights were invaluable for this report. Thanks also to Neshwin Rodrigues, Richard Black and Sarah Brown.

Thank you to Jivan Zhen Thiru for his support in data visualisation.