India Plans Mandatory Battery Storage at Solar and Wind Projects

India's government intends to enforce a new rule, effective from July 1, 2027, mandating solar and wind energy developers to incorporate battery storage at their facilities. This move aims to better manage the intermittent nature of renewable energy output and decrease curtailments. For projects commencing after July 1, 2027, developers must install energy storage systems equivalent to a minimum of 10% of the project's installed capacity, with a minimum storage duration of two hours.

The rule will become stricter for projects initiated between July 2029 and 2031, requiring battery storage equal to at least 10% of installed capacity and a minimum duration of four hours, according to draft proposals.

Despite a surge in solar and wind installations, India has faced challenges in fully leveraging its renewable energy capacity due to frequent curtailments. These curtailments occur when the power grid is unable to absorb the excess energy produced, especially during peak hours and scorching summer months when curtailments are most common. To attract investors and minimize curtailments, solar power developers in India have started incorporating battery storage into their photovoltaic projects.

The Indian electricity grid is expanding at a slower rate than the rapid growth in renewable energy installations, resulting in a growing share of curtailed clean energy and threatening to impede the solar and wind boom in the world's most populous nation. According to a report by Ember, a clean energy think tank, grid and transmission constraints accounted for nearly two-thirds of all renewable energy curtailments, or 300 gigawatt-hours, during the first quarter of the year.

Ember's separate analysis in June suggested that India urgently needs around 10 GWh of battery storage to prevent renewable energy curtailment when the coal-fired electricity generation cannot be reduced below its technical minimum.