NHPC commissions 250 MW unit at Subansiri Lower project

NHPC Limited has declared commercial operation date (CoD) of Unit 1 (250 MW) of the Subansiri Lower Hydroelectric Project, effective 00:00 hours on March 20, 2026. With this, three units of 250 MW each, totalling 750 MW, are now operational. The remaining five units are to be commissioned in phases, with timelines to be announced separately.

Project status and history
The Subansiri Lower Hydroelectric Project, with a total capacity of 2,000 MW across eight units, is located on the Assam–Arunachal Pradesh border. It is among the largest hydropower projects under development in India.

Construction was halted in 2011 following protests by downstream communities in Assam over flood and seismic safety concerns. Work resumed after extended litigation, technical reviews, and design modifications. Unit 2 achieved CoD in October 2023, followed by Unit 3, with Unit 1 now added to the operational capacity.

At full capacity, the project will contribute 2,000 MW to the northeastern grid and add to India’s hydropower capacity. The staged commissioning is expected to support regional supply and grid stability as additional units are brought online.

Earlier, on March 1, 2026, NHPC lowered the 673 metric tonne (MT) generator rotor of Unit 5 into the generator pit at 11:00 hours. The company stated that this is the heaviest equipment component handled at a hydroelectric power plant in India.