The National Hydroelectric Power Corporation (NHPC) has declared the commercial operation of Unit 4 of the Subansiri Lower Hydroelectric Project (SLHEP), adding another 250 MW to the national power grid and taking the project’s total operational capacity to 1,000 MW.
The commissioning marks another major milestone in the phased development of the 2,000 MW hydropower project, which is being developed on the Subansiri River along the Assam-Arunachal Pradesh border.
The SLHEP, comprising eight units of 250 MW each, is the largest hydroelectric project in the country.
The NHPC informed that the remaining units – Units 5 to 8 – are scheduled to be commissioned in a phased manner by the end of this year.
Once fully operational, the project is expected to generate around 7,421 million units of electricity annually and significantly improve power availability across the Northeast.
Construction of the project began in 2005, but it faced numerous issues and controversies that led to the suspension of work from December 2011 to October 2019 following protests in downstream Assam over safety concerns and possible downstream impacts.
By the end of 2019, construction resumed despite continuing controversies surrounding the non-fulfilment of requirements as well as major safety concerns. As the project nears completion, Subansiri will become an important part of the country’s power supply chain. Even though the PSU maintains that the project has been planned and implemented in accordance with statutory requirements and government guidelines, with emphasis on environmental protection, safety, and socioeconomic welfare, the project has been mired in controversy, as several protocols were allegedly violated and multiple landslides raised safety concerns. The PSU must ensure that safety features are not undermined and remain at the core of the project.