India Proposes Mandatory Battery Storage for New Solar and Wind Projects

India is moving to strengthen grid flexibility as renewable energy continues to expand. Under a draft regulation proposed by the Central Electricity Authority (CEA), new utility-scale solar and onshore wind projects would be required to install battery energy storage systems alongside their generation facilities from 2027.

Storage Requirement to Start in 2027

Projects commissioned from July 1, 2027 would need storage capacity equivalent to at least 10% of the project’s installed capacity, with a minimum storage duration of two hours.

For example, a 100 MW solar project would need at least 10 MW/20 MWh of battery storage.

For projects commissioned between July 1, 2029 and June 30, 2031, the minimum storage duration would increase to four hours, meaning a 100 MW project would require 10 MW/40 MWh of storage.

Reducing Renewable Energy Curtailment

The proposed policy comes as India faces growing challenges in absorbing surplus solar and wind power. During the first quarter of the current fiscal year, more than 8,133 GWh of solar generation was curtailed because the grid could not accommodate excess daytime output.

Battery storage could help shift surplus renewable electricity to periods of higher demand and reduce renewable energy curtailment.

Grid-Forming Technology Also Targeted

The draft also proposes that at least 15% of inverters in renewable energy projects connected after July 1, 2027 must have grid-forming capabilities. Battery storage power conversion systems (PCS) would also be required to support grid-forming functions.

As the share of inverter-based renewable generation increases, these technologies are expected to play a growing role in maintaining grid voltage, frequency and stability.

Stakeholders have until October 4 to submit comments on the proposed amendments.