NHPC commissions second unit of Subansiri Lower Project, adds 250 MW to grid

Guwahati, Feb 4: NHPC Limited has started commercial operation of the second unit (Unit # 3 of 250 MW) of its Subansiri Lower Hydro Electric Project, adding another 250 MW of hydropower to the national grid.

With this, the 2,000-MW (8×250 MW) Subansiri Lower HE Project has contributed 500 MW out of its total 2,000 MW capacity.

The commercial operation was achieved on February 1, and ahead of that, the synchronization of the third unit (Unit #1 of 250 MW) with the national grid was accomplished on the night of January 31.

NHPC Limited had officially commenced commercial operation of the first unit (Unit #2 of 250 MW) of the 2,000-MW project on December 23, 2025.

Located on the Assam-Arunachal Pradesh border, this marked a significant step in commissioning India’s largest hydropower project. The eight-unit project is scheduled to be fully operational in a phased manner by 2026-27.

India’s largest hydropower project, the Subansiri lower project comprises eight units of 250 MW each and is designed as a run-of-the-river scheme with small pondage.

It diverts water through eight head race tunnels to generate 7,422 million units of renewable electricity annually.

The project features the largest dam in Northeast India – a 116-metre-high concrete gravity dam – which strengthens regional infrastructure and grid resilience.

NHPC also claims it will enhance flood moderation and water management in the Subansiri river basin, reinforcing hydropower’s role in grid stability, peak power support and integration of renewable energy into the national energy mix.

Bhupender Gupta, CMD, NHPC, while expressing gratitude to the Ministry of Power and the Governments of Arunachal Pradesh and Assam, lauded the dedicated efforts of the Subansiri Lower Project team, led by Rajendra Prasad, Executive Director, and all the officials of various departments of NHPC at corporate office who contributed towards the milestones.

Gupta added that the successful commissioning of the units demonstrated NHPC’s technical expertise, execution capability and crucial role in ensuring national energy resilience and the Government of India’s vision of a sustainable and self-reliant power sector.

He emphasized that the achievements would support timely commissioning of the remaining units.

Sanjay Kumar Singh, Director (Projects), NHPC, congratulated the entire team of NHPC at site and corporate office which contributed to the achievement.

Rajendra Prasad, Executive Director, Subansiri Lower HE Project, thanked the NHPC management, corporate teams, and the executing agencies – GE Vernova, BGS-SGS-SOMA, TREL and PEL as well as local stakeholders and communities for their support.