NHPC Synchronizes Unit-3 (250 MW) of Subansiri Lower Project with National Grid

NEW DELHI / GERUKAMUKH – NHPC Limited has achieved a historic breakthrough in India’s renewable energy landscape with the successful synchronization of Unit–3 (250 MW) of the Subansiri Lower Hydroelectric Project (SLHEP). The unit was officially connected to the National Grid at 9:00 PM on January 21, 2026.

This milestone marks a decisive step toward the full operationalization of what will soon be India’s largest hydroelectric power project, boasting a total installed capacity of 2,000 MW.

Project Progress and Unit Status

The synchronization of Unit-3 follows a rapid series of successes at the project site located on the border of Arunachal Pradesh and Assam:

Engineering a Mega-Structure

The Subansiri Lower Project is a marvel of modern engineering, featuring several "firsts" for the Indian hydropower sector:

• The Dam: A 116-meter-high concrete gravity dam, designed as a run-of-the-river scheme with limited storage to minimize environmental impact.
• The Powerhouse: An underground facility housing eight Francis turbines of 250 MW each.
• Flood Moderation: The project provides a dedicated 442 million cubic meter flood cushion, playing a vital role in protecting downstream communities in Assam during the monsoon.

Leadership & Collaboration

Shri Bhupender Gupta, Chairman and Managing Director of NHPC, credited the achievement to the seamless coordination between the Ministry of Power and the State Governments of Arunachal Pradesh and Assam. He specifically lauded the Subansiri Project team and key executing agencies:

• GE Vernova (Electromechanical works)
• BGS-SGS-SOMA JV (Major civil works)
• TREL & PEL (Infrastructure and additional civil works)

Strategic Impact

Once all eight units are online, SLHEP will generate 7,422 million units (MU) of clean electricity annually. It is expected to be a cornerstone for:

• Grid Stability: Providing essential "peaking" power to balance the intermittency of solar and wind energy.
• Regional Growth: Supplying 1,000 MW of dedicated power to the North Eastern region.
• Net Zero Goals: Contributing significantly to India's commitment to reach 500 GW of non-fossil fuel capacity by 2030.