Subansiri Lower, India's largest hydropower project, begins commercial operation of first unit
Union Power Minister Manohar Lal on 23 December 2025 inaugurated commercial operation of Unit-2 (250 MW) of NHPC's 2,000 MW Subansiri Lower Hydroelectric Project on the Assam–Arunachal Pradesh border.
Summary
Union Power Minister Manohar Lal virtually inaugurated commercial operation of Unit-2 (250 MW) of NHPC's 2,000 MW Subansiri Lower Hydroelectric Project, India's largest hydropower project, on 23 December 2025. Located at Gerukamukh on the Assam–Arunachal Pradesh border, the Subansiri Lower project is a run-of-the-river scheme with eight 250 MW units, designed to generate 7,422 million units a year, and has a 116-metre concrete gravity dam, the largest in North-East India. Three more units are to be commissioned shortly and the remaining four in 2026–27; the project will supply 16 beneficiary states, give free power to Arunachal Pradesh and Assam, and allot 1,000 MW to the North-East.
Key facts
- Date
- 23 December 2025
- Unit
- Unit-2, 250 MW (first unit in commercial operation)
- Capacity
- 2,000 MW (8 × 250 MW), run-of-the-river
- Location
- Gerukamukh, Assam–Arunachal Pradesh border; Subansiri river
- Dam
- 116 m concrete gravity dam, largest in North-East
- Output / share
- 7,422 MU a year; 16 beneficiary states; 1,000 MW to North-East
Practice MCQs 3 questions
What is the total installed capacity of the Subansiri Lower Hydroelectric Project, whose first unit began commercial operation in December 2025?
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Correct answer: D — 2,000 MW
PIB 2207797: the Subansiri Lower project is 2,000 MW (8 × 250 MW); the North-East will receive 1,000 MW from it.
The Subansiri Lower Hydroelectric Project is located along the border of which two states?
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Correct answer: B — Assam and Arunachal Pradesh
Deccan Herald and TOI: the project at Gerukamukh is situated along the Assam–Arunachal Pradesh border.
Consider the following statements about the Subansiri Lower Hydroelectric Project: 1. It is designed as a run-of-the-river scheme with small pondage. 2. Its dam is a 116-metre concrete gravity dam, the largest in North-East India. 3. It is being developed by NTPC Limited. Which of the statements given above is/are correct?
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Correct answer: A — 1 and 2 only
PIB 2207797: Subansiri Lower is a run-of-the-river scheme with small pondage and has a 116-m concrete gravity dam, the largest in the North-East. The developer is NHPC, not NTPC, so statement 3 is wrong.