India's authorities plan to introduce, from July 1, 2027, a regulation requiring developers of solar and wind energy projects to have battery storage installed at their sites in a bid to better manage renewable energy output and reduce curtailments.

Under draft proposals from India's Central Electricity Authority (CEA), solar and wind projects commissioned after July 1, 2027 would be mandated to have co-located energy storage equal to at least 10% of the renewable project's installed capacity, with a minimum duration of two hours.

The proposed regulation would become more stringent for projects commissioned between July 2029 and 2031, requiring battery storage of at least 10% of installed capacity with a minimum duration of four hours, according to the draft proposals.

The move follows a similar approach taken in other major renewable markets. China, the world's largest installer of solar and wind capacity, has pushed for co-located storage on new renewable projects, and several U.S. states, including California, have mandated or incentivized storage additions to manage solar-heavy grids. India, which has set a target of 500 GW of non-fossil power capacity by 2030, is now aligning its regulations with that push.

Despite a major solar and wind installation boom in recent years, India has struggled to fully utilize these capacities because output has often been curtailed due to the lack of battery storage.

As a result, solar power developers in India have started adding battery storage to photovoltaic projects to attract buyers and reduce the large share of curtailments of power supply that the grids are unable to absorb, Santosh Sarangi, Secretary of India's Ministry of New and Renewable Energy, said last month.

Without battery backup, solar projects experience curtailments during the hottest months and peak daytime hours.

India's electricity grid is expanding at a slower pace than the boom in renewable energy installations, leading to an increased share of clean energy curtailments and threatening to slow the solar and wind boom in the world's most populous country.

Grid and transmission constraints accounted for nearly two-thirds of all renewable energy curtailment, totaling 300 gigawatt-hours (GWh) in the first quarter of the year, clean energy think tank Ember said in a report in May.

In a separate analysis in June, Ember said that India needs around 10 GWh of battery storage immediately to stop renewable energy curtailment when the coal fleet cannot ramp down below its technical minimum.

The draft regulation, if finalized, would be watched closely by battery suppliers and project developers, as mandating co-located storage at this scale could significantly expand demand for grid-scale batteries in one of the world's fastest-growing clean energy markets. The CEA is expected to seek stakeholder feedback on the draft proposals before finalizing the rules.

By Tsvetana Paraskova for Oilprice.com