NHPC’s Subansiri Lower Hydroelectric Project Has Now Achieved 50% Of Its Planned 2,000 MW Capacity.

Guwahati; May 2026: Commercial operation of the fourth unit (250 MW) of NHPC’s 2,000 MW (8×250 MW) Subansiri Lower Hydroelectric Project (SLHEP) located in Arunachal Pradesh and Assam started on Friday (08th May 2026). With the commissioning of this unit, SLHEP has achieved a total operational capacity of 1,000 MW out of its planned 2,000 MW capacity, marking a milestone in the project’s phased commissioning. The remaining units are expected to commissioned within the scheduled timelines.

“The unit commenced commercial operation at 00:00 hrs on May 8, 2026 adding 250 MW of clean energy to the national grid”, an official statement from NHPC stated. NHPC had begun construction in January 2005 after receiving forest clearance in October 2004. Work on the major project along the Subansiri river came to a halt between December 2011 and October 2019 due to protests in Assam over safety concerns and potential downstream impacts. Following the resolution of all legal challenges raised by the National Green Tribunal (NGT), NHPC resumed construction with certain design modifications starting on October 15, 2019. The Subansiri project was initially planned to be completed by December 2012.

However, the project cost has increased more than fourfold, rising from an initial estimate of Rs 6,285 crore in December 2002 to around Rs 27,000 crore at completion. “SLHEP has been planned and implemented in accordance with statutory requirements and government guidelines, with due emphasis on environmental protection, safety and socioeconomic welfare”, AN Mohammed, consultant for SLHEP, NHPC, told media reporters. “Since inception, the project has undergone comprehensive scientific studies, regulatory appraisal and review by independent expert committees to address environmental, geological and social concerns associated with large infrastructure projects in the Subansiri-Brahmaputra river system,” he said.

Taking into account the seismic history, hydrological characteristics and ecological sensitivity of the region, the project design incorporates robust safety features, sediment management provisions and year-round environmental flow releases to maintain downstream river ecology. Flood moderation measures have also been integrated, enhancing downstream safety during monsoon periods and contributing to basin-level resilience, he added. Claiming that social impact of the project has been minimized, Mohammed said that no habitation is being submerged, and limited agricultural land affected is being addressed through rehabilitation and compensation in accordance with the Arunachal Pradesh Rehabilitation and Resettlement Policy. “Compensatory afforestation is being undertaken over a substantially larger area of degraded forest land in Arunachal Pradesh and Assam through CAMPA funds. To further safeguard downstream areas, riverbank protection works, real-time flood forecasting and early-warning systems have been established. Project operations are supported by advanced monitoring and control systems to ensure safe and regulated functioning” he said.

On the launch of the fourth unit’s commercial operation, NHPC CMD Bhupender Gupta expressed gratitude to the Union Ministry of Power, and the State governments of Arunachal Pradesh and Assam for their support. He also appreciated the efforts of the SLHEP and contributions of various departments at NHPC. Gupta stated that the successful commissioning highlights NHPC’s strong technical expertise and project execution capabilities and further reinforces its pivotal role in strengthening India’s energy security in line with the Government of India’s vision of a sustainable and self-reliant power sector. In addition to power generation, sustained investments have been made in community development through livelihood support, education, healthcare, drinking water facilities, skill development and other socioeconomic initiatives in project-affected and nearby areas of Arunachal Pradesh and Assam. Power generated from the project is equitably shared, with free power benefits accruing to the host states and improved clean energy availability for the wider region.

Team Maverick.