NHPC Subansiri Project Reaches 750 MW Capacity in 2026

Introduction

State-owned NHPC Limited has achieved a significant milestone in the development of India's largest hydroelectric project. The company announced the commercial operation of the third 250 MW unit of its 2000 MW Subansiri Lower Hydroelectric Project on March 20, 2026. This latest addition brings the project's total operational capacity to 750 MW, marking steady progress in its phased commissioning plan.

A Phased Commissioning Timeline

The journey to 750 MW has been achieved through a series of planned activations over several months. The first unit to come online was Unit #2, which began commercial operation on December 23, 2025. This was a landmark event, initiating the flow of power from the massive project to the national grid.

Following this, NHPC commissioned the second operational unit, Unit #3, on February 1, 2026. This step doubled the project's contribution to 500 MW. The most recent development was the commissioning of Unit #1 on March 20, 2026, which completed the first phase of bringing 750 MW of capacity into service. The company has followed all regulatory protocols, informing stock exchanges under SEBI regulations for each commissioning event.

Current Project Status

With three of its eight units now operational, the Subansiri Lower HE Project is substantially contributing to the national grid. The project is designed with eight identical units, each with a generation capacity of 250 MW. The remaining five units are scheduled for commissioning in a phased manner.

Project Specifications and Strategic Importance

Located on the Subansiri River along the border of Arunachal Pradesh and Assam, the project is a run-of-the-river scheme with a small pondage. It features a 116-metre-high concrete gravity dam, the largest in Northeast India. This infrastructure is not only crucial for power generation but also enhances flood moderation and water management in the river basin.

As India's largest hydroelectric project, Subansiri Lower is a strategic asset for the country's clean energy ambitions. It is designed to strengthen grid stability, particularly in the North-Eastern region, and provide essential peak power support. This capability is vital for integrating intermittent renewable energy sources like solar and wind into the national energy mix.

Power Generation and Distribution

Once fully operational, the 2000 MW facility is projected to generate approximately 7,422 million units of renewable electricity annually. This output will significantly bolster India's green energy portfolio. The power generated will be distributed to 16 beneficiary states, with Assam and Arunachal Pradesh receiving free power allocations as host states. The Northeast region is set to receive 1,000 MW from the project, which will enhance regional energy security.

Economic and Community Impact

The project, constructed at an estimated cost of around Rs 27,000 crore, has also had a considerable socio-economic impact. During its construction phase, it provided daily employment for approximately 7,000 local individuals and created numerous indirect job opportunities. Furthermore, NHPC has invested about Rs 155 crore in Corporate Social Responsibility (CSR) activities in Assam and Arunachal Pradesh, including community development programs focused on livelihood initiatives for local women.

Future Outlook

NHPC has indicated that the remaining five units, accounting for 1250 MW of capacity, will be commissioned in phases through 2026 and 2027. The company will continue to provide updates on the commercial operation dates for these units as they are achieved. The successful and sequential commissioning of the first three units provides confidence in the project's timeline for full completion.

Conclusion

The commissioning of the third unit at the Subansiri Lower Hydroelectric Project is a testament to NHPC's execution capabilities and a major step forward for India's renewable energy sector. With 750 MW now online, the project is already a key contributor to the national grid. Its full commissioning will play a pivotal role in meeting the country's rising power demands with clean, reliable, and sustainable energy.