NHPC Limited will commence commercial operation of Unit 5 (250 MW) at the Subansiri Lower Hydroelectric Project on October 23, 2026, taking the project’s operational capacity to 1,250 MW.
Key Highlights
- New Capacity – 250 MW Unit-5
- Total Project Capacity – 2,000 MW
- Operational Capacity – 1,250 MW
- Remaining Capacity – 750 MW
- Energy Type – Hydropower Energy
- Source – Subansiri River
- Project Location – Assam–Arunachal Pradesh border.
- Developer – NHPC Limited.
India’s premier green energy Navratna Public Sector Enterprise under the Ministry of Power, Government of India, NHPC Limited has declared the Commercial Operation Date (CoD) of Unit 5, with an installed capacity of 250 MW, at its 2,000 MW Subansiri Lower Hydroelectric Project located on the Assam–Arunachal Pradesh border. The unit will become commercially operational from 00:00 hours on October 23, 2026, marking another milestone in the commissioning of the major hydropower project.
With the addition of Unit 5, five of the project’s eight generating units have achieved commercial operation, taking the total commercially operational capacity to 1,250 MW. The remaining three units, with a combined capacity of 750 MW, are yet to achieve their respective Commercial Operation Dates.
Subansiri Lower Project Reaches 1,250 MW Operational Capacity
The Subansiri Lower Hydroelectric Project has a planned installed capacity of 2,000 MW, comprising eight generating units of 250 MW each. The project is being developed by NHPC Limited on the Subansiri River, along the boundary of Assam and Arunachal Pradesh.
The declaration of CoD for Unit 5 represents 62.5% of the project’s total installed capacity becoming commercially operational. The remaining capacity is expected to be brought into operation as the commissioning process progresses. NHPC has stated that the commercial operation dates of the remaining units will be communicated in due course.
Once fully operational, the project is expected to make a substantial contribution to India’s electricity generation capacity, particularly in the northeastern region. Large hydropower projects play an important role in supporting grid reliability and meeting electricity demand through renewable energy generation.
Hydropower to Support India’s Renewable Energy Mix
The commissioning of additional generating capacity at Subansiri Lower comes amid India’s broader efforts to expand its power infrastructure and diversify its electricity mix. Hydropower can complement solar and wind generation by providing flexible electricity supply, subject to water availability, reservoir conditions and operational requirements.
For NHPC, the progress at Subansiri Lower represents a significant step towards commissioning the project’s full 2,000 MW capacity. The development also strengthens the region’s hydropower infrastructure and supports the long-term availability of electricity for the national grid.
With five units now declared commercially operational, attention will turn towards the commissioning of the remaining three units. Their commercial operation will be an important milestone in completing the project and unlocking its full installed generation capacity.
The latest announcement underscores the continuing progress of one of India’s major hydropower developments, with 250 MW of additional capacity scheduled to enter commercial operation from October 23, 2026.