India's Largest Hydropower Project Achieves Key Milestone

In a significant development, NHPC achieved a milestone with the successful synchronisation of the 250 MW Unit (Unit-2) of the 2,000 MW Subansiri Lower HE Project (one of eight 250 MW units) with the National Grid. This is seen as a crucial phase of the mega dam project in Arunachal Pradesh, which is India's largest hydroelectric power-generating station.

NHPC, in a statement, said the commissioning process commenced with Unit-1 and Unit-2, which underwent mechanical run on October 24 and November 6. NHPC also added that the crucial synchronisation of the remaining three units-Unit-1, Unit-3, and Unit-4-will proceed upon completion of comprehensive testing.

The project will deliver 1,000 MW of output.

Upon completion, the Subansiri Lower HE Project is expected to contribute 7.421 billion units of renewable energy annually, strengthening the country's energy sector and moving forward to fulfil India's carbon neutrality target.

The Subansiri Lower HEP has seen many hurdles after being greenlit in January 2005 at Gerukamukh on the Arunachal Pradesh-Assam border.

Construction came to a halt for eight years between 2011 and 2019 due to anti-dam protests. Project construction started back up in October 2019.

NHPC further stated: "As a national endeavour, power allocation adheres to central hydropower norms. Assam, beyond its standard 208 MW share, secures a preferential 300 MW allotment plus 25 MW of free electricity. Arunachal Pradesh will get 12% free power as per the national hydropower policy. The remaining power is allotted to other states, including the northeast states of India."

Upon full commissioning, the 2,000 MW capacity will substantially strengthen the nation's renewable energy portfolio and significantly enhance electricity access throughout the critical northeastern region. The momentous achievement aligns perfectly with India's broader goals of increasing clean energy production and reducing dependence on fossil fuel generation.