Itanagar, Oct 13 Power major NHPC on Tuesday said it has synchronised the fifth 250-megawatt unit of the 2,000 MW Subansiri Lower Hydroelectric Project in Arunachal Pradesh with the national grid, taking the total synchronised capacity of the mega project to 1,250 MW.
The unit was synchronised at 9 pm on Monday, marking another milestone in the phased commissioning of the project, which is located on the Subansiri river along the Arunachal Pradesh-Assam border.
The project comprises eight generating units of 250 MW each. Once all the units are operational, it will have an installed capacity of 2,000 MW and is expected to generate about 7,422 million units of electricity annually, the company said.
The synchronisation of the fifth unit is a significant step in the project’s commissioning process.
Synchronisation involves connecting a generator to the electricity grid after the completion of necessary technical checks, allowing it to operate in coordination with the wider power system. Commercial operation, however, is declared separately after the required testing and procedures are completed.
Four units of the project, with a combined capacity of 1,000 MW, had already entered commercial operation before the latest development. The fifth unit adds another 250 MW to the capacity synchronised with the grid, while work continues on the remaining three units, officials said.
The project is expected to play an important role in meeting rising electricity demand in the Northeast and strengthening the national power network, the NHPC said.
The Subansiri Lower project had faced prolonged delays in the past amid concerns over dam safety and its downstream impact. Construction resumed in 2019 following the implementation of additional safety and mitigation measures.
Its completion is expected to increase the availability of renewable electricity and contribute to grid stability. The project is also envisaged to provide flood-moderation benefits in the Brahmaputra Valley, subject to operating conditions and coordinated river management, officials said.
The full commissioning of the project is now targeted for March 2027, with the remaining generating units scheduled to be brought into operation in phases.
The earlier target was December this year, according to the Ministry of Power.
The revised timeline comes as NHPC continues work on the project’s remaining units, including the installation of major electromechanical equipment, officials added.
(PTI News)
