Subansiri Lower Hydroelectric Project hits 1,000 MW as Unit 4 commissioned
Synopsis
India's largest hydroelectric project has crossed the halfway mark — with four of eight units now live and 1,000 MW operational, the Subansiri Lower Hydroelectric Project is on track for full 2,000 MW commissioning by December 2026, promising to reshape power supply across the Northeast and advance India's clean energy targets.
Key Takeaways
NHPC commissioned Unit 4 (250 MW) of the Subansiri Lower Hydroelectric Project effective 8 May 2025 .
Total operational capacity has reached 1,000 MW — half of the project's 2,000 MW installed capacity.
Full commissioning of all eight units is targeted by December 2026 .
The project is expected to generate more than 2,500 employment opportunities and attract over 1.5 lakh tourists annually .
Chief Minister Pema Khandu has written to PM Narendra Modi seeking Central support for the project's broader development.
Arunachal Pradesh Deputy Chief Minister Chowna Mein on 10 May 2025 congratulated state-run NHPC for successfully commissioning Unit 4 (250 MW) of the Subansiri Lower Hydroelectric Project — India's largest hydroelectric project — bringing its total operational capacity to 1,000 MW. NHPC declared the commercial operation of Unit 4 effective from 8 May 2025, marking a significant milestone in the project's phased rollout.
Key Developments
The 2,000 MW Subansiri Lower Hydroelectric Project, located on the Subansiri River along the Assam–Arunachal Pradesh border, comprises eight units of 250 MW each. With four units now operational, the project is exactly halfway to its full installed capacity. According to an official of the Arunachal Pradesh Power Department, full commissioning is expected by December 2026.
What Chowna Mein Said
Mein, who also holds the Power and Non-Conventional Energy Resources portfolio, described the commissioning as a major milestone in India's pursuit of clean, sustainable, and self-reliant energy generation. In a social media post, he said:
Point of View
Not just a headline target. What deserves closer scrutiny is whether the promised eco-tourism and livelihood integration actually materialises, or whether it remains a political talking point used to smooth over the project's fraught history with affected communities.
NationPress
11 May 2026
Frequently Asked Questions
What is the Subansiri Lower Hydroelectric Project?
The Subansiri Lower Hydroelectric Project is India's largest hydroelectric project, being developed by NHPC on the Subansiri River along the Assam–Arunachal Pradesh border. It has an installed capacity of 2,000 MW, comprising eight units of 250 MW each.
How much capacity is operational now?
As of 8 May 2025, four of the eight units are operational, bringing the total commissioned capacity to 1,000 MW. The remaining four units are expected to be commissioned by December 2026.
Why was the Subansiri project delayed for so many years?
The project faced years of delay due to environmental and social concerns, as well as prolonged public agitations. Construction resumed in 2019 after these issues were partially addressed.
What is the significance of this project for Northeast India?
Once fully operational, the project is expected to significantly enhance electricity availability across the Northeastern region and contribute to India's clean energy goals. It is also projected to generate more than 2,500 long-term employment opportunities and attract over 1.5 lakh tourists annually.
What role is the Central government playing in the project?
Chief Minister Pema Khandu has written to Prime Minister Narendra Modi seeking Central support and technical collaboration from key ministries including Tourism, Power, Jal Shakti, Ports, Shipping and Waterways, and DoNER for the project's holistic development.
