NHPC declares CoD of 250 MW Unit 4 at Subansiri Lower project

NHPC Limited has declared the Commercial Operation Date (CoD) of Unit 4 (250 MW) of the Subansiri Lower Hydroelectric Project (SLHEP) with effect from 00:00 hours on May 8, 2026.

The project, located across Assam and Arunachal Pradesh, has a total installed capacity of 2,000 MW (8×250 MW). With Unit 4 now operational, four units—Unit 1, Unit 2, Unit 3, and Unit 4—are in commercial operation, taking the commissioned capacity to 1,000 MW. NHPC stated that timelines for the remaining four units will be announced separately.

The SLHEP is among the largest hydroelectric projects under development in India. Its phased commissioning is being closely tracked due to its scale and expected contribution to renewable energy capacity through large hydro. Unit 1 (250 MW) achieved CoD on March 20, 2026, taking operational capacity at that stage to 750 MW.

Once fully operational, the 2,000 MW project is expected to support power supply in the northeastern region and contribute to grid stability as additional units are brought online.

Photo credit: NHPC