India’s largest hydropower project undergoes test run

GUWAHATI

One of the eight units of India’s largest hydropower project, located on the Arunachal Pradesh-Assam border, has started its test run, signaling that it will be commissioned soon.

NHPC Limited officials said that wet commissioning of the first 250 megawatt unit of the 2,000 MW Subansiri Lower Hydropower Project started on Friday, October 24, 2025.

“Wet commissioning is basically a test run of the turbine to check various parameters without generating electricity. The test run with water flow can take four to five days,” said an NHPC spokesperson. Hindu On Saturday, October 25th.

The Subansiri Lower project has eight units of 250 MW each. “Four of these units are ready for test runs. The next step involves synchronizing at least two units for the project to start generating power,” he said.

The Subansiri Lower project, located at Gerukamukh on the inter-state border, was launched in January 2005. Work on the project was suspended in 2011 following protests by anti-dam activists in Assam and concerns about downstream environmental impacts.

Work resumed in October 2019 after the Prime Minister’s Office pushed for completion and the NHPC agreed to enhanced mitigation and safety measures.

NHPC Chairman and Managing Director Bhupender Gupta, who attended the wet commissioning event, stated that this achievement is a “shining testament” to the company’s engineering excellence. “This is more than just a project milestone; it reflects India’s steady progress towards a cleaner, greener and self-sufficient energy future,” he said.