The 456-megawatt Upper Tamakoshi Hydropower Project, Nepal’s largest so far, reached a milestone on Monday with one of its six 76-megawatt units starting power generation.

Once the project starts evacuating power from all its six units to the national grid, Nepal will earn the status of becoming a power surplus country during the wet season.

Prime Minister KP Sharma Oli inaugurated the project located on the Tamakoshi River in Dolakha district in north-central Nepal, approximately 200km away from Kathmandu, by pressing a button during a video conference from Baluwatar.

For the run-of-river hydropower project, which will have little or no storage capacity, the winter [December-February] is the dry season when Nepal’s Himalayan peaks do not melt and the low water flows lead to lower energy availability.

The Upper Tamakoshi plant, however, can generate electricity at full capacity for four hours during the dry season, according to the project.

“This is a historic achievement,” said Hitendra Dev Shakya, managing director at the Nepal Electricity Authority. “This makes Nepal a power surplus country capable of exporting electricity.”

As a major project in Nepal, this is the largest and most technically difficult, with an underground powerhouse, which is an engineering marvel, project officials said.