New Delhi: India’s hydropower sector received a major boost as NHPC Limited announced the commercial operation of Unit 4 of its flagship Subansiri Lower Hydroelectric Project (SLHEP), adding 250 MW of clean energy to the national grid.
The latest addition takes the project’s operational capacity to 1,000 MW, marking a significant milestone in one of India’s largest hydropower developments.
Unit 4 Goes Into Commercial Operation
The 250 MW Unit 4 began commercial operations at midnight on May 8 after successfully completing its trial run on May 1. With this addition, four out of the eight generating units are now operational.
This milestone reflects steady progress in the phased commissioning of one of India’s largest hydropower projects.
Read also: NHPC Commissions 4th Unit of 2,000 MW Subansiri Hydro Project, 1,000 MW Now Operational
1,000 MW Operational Milestone Achieved
The Subansiri Lower Hydroelectric Project has a total planned capacity of 2,000 MW, and with 1,000 MW now operational, the project has reached half of its installed capacity.
The remaining four units are expected to be commissioned in phases by the end of 2026.
Strategic Role in Power Supply and Grid Stability
Located on the Subansiri River along the Assam-Arunachal Pradesh border, the project is expected to play a key role in:
- Strengthening national grid stability
- Meeting peak electricity demand
- Supporting renewable energy integration
Once fully operational, the project is expected to generate around 7,421 million units (MU) of electricity annually.
Contribution to Clean Energy and Climate Goals
The project will also contribute significantly to India’s clean energy transition. It is estimated to reduce carbon emissions by nearly 7 million tonnes annually, supporting national climate targets.
Long Development Journey of the Project
The Subansiri Lower Hydroelectric Project has faced a long and complex construction timeline:
- Construction began in 2005 after forest clearance in 2004
- Work was halted between 2011 and 2019 due to protests and safety concerns
- Construction resumed in October 2019 after legal and technical issues were resolved
Since then, the project has moved forward with updated safety measures and environmental safeguards as per regulatory approvals.
About NHPC Limited
NHPC Limited is a Navratna public sector enterprise and India’s leading hydropower company. Headquartered in Faridabad, it focuses on the development and operation of hydroelectric and renewable energy projects across the country, playing a key role in India’s clean energy transition.
Read also: NHPC Appoints Anish Gouraha as Regional Head for J&K and Ladakh Hydropower Operation
