The 2,000-megawatt Subansiri Lower Hydroelectric Project has achieved a major milestone in its construction and commissioning process. Engineers successfully lowered the 395-metric-tonne generator stator of Unit 7 on September 30, bringing the project closer to its full installed capacity.
Arunachal Pradesh Deputy Chief Minister Chowna Mein announced the development on October 1. He described the achievement as an important step towards commissioning the seventh generating unit and strengthening the region’s power infrastructure.
The National Hydroelectric Power Corporation (NHPC) is developing the project on the Subansiri River along the Arunachal Pradesh-Assam border. The project will have eight generating units, each with a capacity of 250 MW. <Cite refs={[“turn323623search0″,”turn323623search6”]}/>
Unit 7 Stator Lowering Marks Major Milestone
The successful lowering of the 395-tonne stator marks a significant stage in the electro-mechanical work of Unit 7.
A generator stator forms a key component of a hydroelectric generator. It works with the rotor to convert mechanical energy from the turbine into electrical energy.
The operation required detailed planning, precision engineering and coordination among the project teams. NHPC and its executing agency, GE Vernova, worked together to complete the activity.
NHPC Chairman and Managing Director Bhupender Gupta congratulated the project team and described the operation as an important step towards commissioning Unit 7.
The successful lowering will allow engineers to continue assembly work inside the unit pit. The team will then proceed with further testing and commissioning activities. <Cite refs={[“turn323623search6″,”turn323623search11”]}/>
Project Comprises Eight 250-MW Units
The Subansiri Lower Hydroelectric Project has an installed capacity of 2,000 MW. Its eight generating units will each produce 250 MW of electricity.
The project has already started supplying electricity through four commercially operational units. These units together provide 1,000 MW of installed capacity.
NHPC commissioned Unit 2 on December 23, 2025, followed by Unit 3 on February 1, 2026. Unit 1 entered commercial operation on March 20, while Unit 4 began commercial operation on May 8.
The remaining four units, including Unit 7, are undergoing construction, installation or commissioning preparations. NHPC is also preparing Unit 5 for commissioning. <Cite refs={[“turn323623search6″,”turn323623search4”]}/>
Project Located Along Assam-Arunachal Border
The Subansiri Lower project stands at Gerukamukh on the Subansiri River, along the boundary between Arunachal Pradesh and Assam.
NHPC is implementing the project as a major hydropower development in the Northeast. Once all eight units operate at full capacity, the project is expected to generate approximately 7,422 million units of electricity annually.
The project also aims to support grid stability. Hydropower can help balance fluctuations in electricity generation from renewable sources such as solar and wind.
The Union Power Ministry has also identified flood moderation benefits for the Brahmaputra Valley among the project’s intended outcomes. <Cite refs={[“turn323623search4”]}/>
Commissioning Work Continues on Remaining Units
The latest achievement brings Unit 7 closer to its commissioning stage. However, engineers must complete further assembly, testing and related work before the unit can begin commercial operation.
NHPC continues to focus on the remaining units to achieve the project’s full installed capacity.
The Power Ministry indicated in March that the project’s remaining units would enter operation in phases through December 2026. The latest stator installation marks progress towards that broader timeline. <Cite refs={[“turn323623search4″,”turn323623search6”]}/>
Chowna Mein Congratulates NHPC Team
Deputy Chief Minister Chowna Mein congratulated NHPC and the Subansiri Lower project team for completing the operation.
He said the milestone would bring Unit 7 closer to commissioning and move the project towards its full 2,000-MW capacity.
The development also highlights the role of large hydropower projects in expanding electricity generation in the Northeast.
As NHPC advances work on the remaining units, the Subansiri Lower project is moving towards its planned full-scale operation. Its completion is expected to add substantial electricity generation capacity and support the wider power network.