NHPC advances Subansiri Lower project with Unit 4 tests

The 2,000 MW Subansiri Lower Hydroelectric Project (SLHEP) has progressed toward commissioning with the start of generator tests for Unit 4 on April 21–22, 2026, during a site visit by Shri Uttam Lal, Director (Personnel) of NHPC Limited.

The project team initiated Short Circuit Characteristic (SCC) and Open Circuit Characteristic (OCC) tests for the 250 MW Unit 4, marking a key stage in electro-mechanical commissioning. Spiral casing concreting was also launched for Unit 7, another 250 MW unit, which is expected to support progress in both civil and electro-mechanical works.

During the visit, Uttam Lal, along with Rajendra Prasad, Executive Director and Head of Project, inspected major facilities including the dam, diversion tunnel inlet, and powerhouse. The review covered overall readiness and timelines for the remaining units, particularly Units 5 to 8.

In interactions with project personnel, Lal acknowledged the team’s progress and emphasised adherence to timelines for commissioning the remaining units.

The Subansiri Lower project is among India’s largest run-of-river hydroelectric schemes and plays a key role in renewable energy supply and grid balancing.

Photo credit: NHPC