Subansiri project hits 1,000 MW production capacity as 4th unit goes live

Dibrugarh: NHPC Limited, a Navratna Public Sector Undertaking under the ministry of power, has declared the commercial operation of the fourth unit (Unit 4 of 250 MW) of its flagship 2,000 MW Subansiri Lower Hydroelectric Project (SLHEP), bringing the project to half its total intended capacity.The unit commenced commercial operation on Friday, adding another 250 MW of clean, renewable energy to the national grid and pushing the project’s total operational capacity to a landmark 1,000 MW.The Subansiri Lower Hydroelectric Project, located on the Arunachal Pradesh–Assam border, is one of India’s largest hydroelectric developments, with construction having commenced in Jan 2005 after obtaining forest clearance on Oct 12, 2004. However, due to agitations and protests by local stakeholders, construction was stalled from Dec 2011 to Oct 2019 — a delay of nearly eight years that significantly pushed back the project’s commissioning timeline.The project’s first unit (Unit 2) was commercially commissioned on Dec 23, 2025, marking the inaugural milestone in the project’s phased rollout. The second unit (Unit 3) followed on Feb 1, 2026, taking the project’s contribution to 500 MW of the national grid. The third unit came online on March 20, 2026, raising total operational capacity to 750 MW.Friday’s commissioning of the fourth unit completes what has been a rapid sequence of activations over the past several months, reaching the symbolic 1,000 MW halfway mark.Bhupender Gupta, chairman and managing director of NHPC said, “The successful commissioning of this unit highlights NHPC’s strong technical expertise and project execution capabilities, and further reinforces its pivotal role in strengthening India's energy security in line with the Centre’s vision of a sustainable and self-reliant power sector.”He conveyed gratitude to the ministry of power and the Arunachal and Assam govts for their continued support, while acknowledging the dedicated efforts of the project team led by executive director Rajendra Prasad and the contributions of various departments at NHPC’s corporate office. He expressed confidence that the remaining units would be commissioned within their targeted timelines.