NHPC is set to begin the commissioning of three units, each with a capacity of 250 MW, at the Subansiri Lower Hydroelectric (HE) Project starting June 2025, pending final clearance from the National Dam Safety Authority (NDSA).

The announcement was made via a regulatory filing, highlighting that approval from NDSA is the only remaining hurdle for this milestone. Located on the Subansiri River and spread across the Arunachal Pradesh-Assam border, the Subansiri Lower HE Project is the largest hydroelectric venture undertaken in India.

With a total planned capacity of 2,000 MW, the run-of-river project incorporates water storage and will significantly contribute to India’s renewable energy infrastructure. The remaining five units, each also with a capacity of 250 MW, are scheduled to be completed in a phased manner by May 2026.

Once fully operational, the Subansiri project is expected to enhance power supply stability across northeastern India and contribute meaningfully to the national grid.