Guwahati, Dec 24: NHPC on Tuesday began partial commercial operations at its long-delayed 2,000 MW Subansiri Lower Hydroelectric Project, located along the Assam-Arunachal Pradesh border, 13 years behind the original December 2012 schedule.
Union Power Minister Manohar Lal inaugurated unit-2 virtually from New Delhi, calling it a “proud milestone” that reflects years of persistent effort. The project comprises eight 250 MW units, with three more expected to be operational soon and the remaining units phased in by 2026-27.
As India’s largest hydropower facility, the run-of-the-river project with minimal pondage will generate 7,422 million units (MU) of clean energy annually through eight head race tunnels. The power will be supplied to 16 states, with 1,000 MW earmarked for the Northeast, and Arunachal Pradesh and Assam receiving free power.
The 116-meter-high concrete gravity dam—the tallest in Northeast India—provides flood moderation with a 442 million cubic meter cushion, safeguarding downstream areas. NHPC has invested Rs 522 crore in riverbank protection up to 60 km downstream.
Construction began in January 2005 after forest clearance but was stalled from December 2011 to October 2019 due to local protests concerning safety and downstream impacts. Work resumed in 2019 following clearance from the National Green Tribunal and committee reviews.
The project cost has risen more than fourfold to Rs 26,075 crore from an initial Rs 6,285 crore. It employs around 7,000 locals daily and has generated numerous jobs. The project also features engineering milestones, including India’s heaviest hydropower rotors and largest stators.
Full commissioning by May 2026 is expected to strengthen India’s renewable energy capacity, enhance grid resilience, and support the nation’s Net Zero goals.
