NHPC Limited has begun commercial operation of the second unit (250 megawatt) of the Subansiri Lower Hydroelectric Project, strengthening India’s renewable energy capacity.

Key developments

• NHPC Limited started commercial operation of Unit 3 (250 megawatt) on February 1, 2026.
• With this, 500 megawatt of power is now operational out of the project’s total capacity of 2,000 megawatt.
• The first unit (250 megawatt) became operational in December 2025.
• The project is scheduled to be fully commissioned in phases by 2026–27.

About the Subansiri Lower Hydroelectric Project

• It is India’s largest hydropower project, located on the Assam–Arunachal Pradesh border.
• The project consists of eight units of 250 megawatt each.
• It is a run-of-the-river scheme with small pondage, reducing large-scale submergence.
• The project is designed to generate about 7,422 million units of renewable electricity annually.

Engineering and strategic features

• The project has the largest dam in Northeast India, a 116-metre-high concrete gravity dam.
• Water is diverted through eight head race tunnels for power generation.
• NHPC states that the project will also support flood moderation and water management in the Subansiri river basin.
• It strengthens grid stability, supports peak power demand, and aids integration of renewable energy.

Exam Hook – 

Q. Consider the following statements:

1. The Subansiri Lower Hydroelectric Project is India’s largest hydropower project.
2. It is a run-of-the-river project with small pondage.
3. The project is located entirely within Assam.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3

Correct answer: (a)

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