New Delhi, June 6 -- India's clean energy push is running into an unexpected hurdle: the country is generating more solar power than its grid can handle, forcing operators to cut supply even as states sign new coal-based power deals.

Data from the Grid Controller of India showed that on 1 May, up to up to 27.34GW of solar capacity-equating to 121.46 GWh of power generation-was curtailed to ensure grid security, including curtailment under emergency TRAS Down mechanism, wherein gencos are directed by the Grid Controller of India to curtail generation.

The solar capacity that was curtailed that day equals almost one-sixth of the country's installed capacity of 150GW. Experts said that low demand due to industries closing for Labour Day on...