NHPC begins wet commissioning of first unit at Subansiri Lower HEP

NHPC Limited has commenced wet commissioning of Unit I (250 MW) of the 2,000 MW Subansiri Lower Hydroelectric Project (HEP) on October 24, 2025, marking the start of commissioning for India’s largest hydropower project. The mechanical run of the first machine was completed successfully, initiating the synchronisation process with the national grid.

The event was attended by NHPC leadership including Bhupender Gupta, CMD; Sanjay Kumar Singh, Director (Projects); Suprakash Adhikari, Director (Technical); Mahesh Kumar Sharma, Director (Finance); Uday Sakharam Nirgudkar, Independent Director; Santosh Kumar, CVO; and Rajendra Prasad, Executive Director & Head of the Project, along with senior corporate and project officials.

Bhupender Gupta acknowledged the support of the Ministry of Power, the governments of Arunachal Pradesh and Assam, former NHPC leadership, the Subansiri project team, executing agencies, and other stakeholders. He described the milestone as a symbol of NHPC’s engineering expertise and India’s progress toward a cleaner, self-reliant energy future.

Following the commissioning of Unit I, three additional 250 MW units are scheduled for synchronisation this year, collectively adding 1,000 MW. Upon full completion, the Subansiri Lower HEP, with eight units of 250 MW each, will be India’s largest hydroelectric project, contributing significantly to national energy security and sustainable development.

The successful wet commissioning sets the stage for the commencement of the commercial operation process and underscores NHPC’s role in advancing India’s renewable energy capacity in the North Eastern region.

Image source: NHPC