Under the Koshi Corridor 220 kilovolt (KV) transmission line project, the construction of the first circuit of the transmission line from Basantpur substation in Dharmadevi municipality of Sankhuwasabha to Dhungesanghu substation in Maivakhola rural municipality of Taplejung has been completed.

Basantpur-Dhungesanghu 220 KV double transmission line has been constructed to integrate the electricity of the hydroelectric projects constructed on the Tamor river and its tributaries into the national transmission system. The length of the Basantpur-Dhungesanghu 220 transmission line, which passes from the sea level up to 3000 meters, is 35 km. 127 towers have been built for transmission lines. Under the Basantpur-Dhungesanghu transmission line, 6 bays are being expanded in the Basantpur substation. Among them, 3 Bays devices are being installed and tested. The goal is to complete the work within the first week of March.

Executive Director of Nepal Electricity Authority, Kulman Ghising said that after the completion of the Basantpur-Dhungesanghu transmission line, there is no problem in the electricity flow of the 73 MW Middle Tamor Hydropower Project being constructed by Sanima Middle Tamor Hydropower Ltd. in Taplejung.

‘Middle Tamor will be connected to the Basantpur-Dhungesanghu transmission line within a few weeks, we have received information that the final phase of the project is currently being tested, and installation and testing of equipment for bay expansion is being done at the Basantpur substation to connect the project’s electricity, by the time the Middle Tamor starts generating electricity at the Basantpur substation The bay expansion will be completed and ready for electricity’, Managing Director Ghising said.

The transmission line and substation have been prepared, but since hydropower projects cannot be built, the 220kV line has to be run at a reduced capacity. The power of the hydropower projects, including Central Tamor will be connected to this line and supplied to Morang and Sunsari districts through the Inruwa substation. As a result, the voltage will be improved and the power supply will be reliable and quality.’

Under the Koshi Corridor Transmission Line Project Package-3, a contract was signed with KIC International, India in January 2018 for 24 million US dollars for the construction of Basantpur-Dhungesanghu 220 KV transmission line and 132-33 KV substation at Dhungesanghu. The contract was implemented from May 2075. The construction of the transmission line has been completed and the construction of Dhungesanghu substation is in the final stage. The Basantpur-Dhungesanghu transmission line was constructed with the investment of the Nepal government and authorities and the concessional loan of the Export Import (Exim) Bank of the Government of India.

Under the Koshi Corridor Transmission Line Project Package-4, construction of the second circuit of Basantpur-Dhungesanghu transmission line and bay extension work is underway at Basantpur substation. Out of the total 35 km of transmission line, 15 km of wire has been laid so far. Bay expansion work is ongoing.

A contract was signed with Nepal Hydro and Electric Ltd. in October 2023 to work on this package. The entire work of this package, which is being built with the investment of the Nepal government and authorities, is set to be completed within the next one and a half months.

Under the Koshi Corridor Transmission Line Package-1, a 220 kV double circuit tower has been constructed from Tumlingtar in Sankhuwasabha to Inruwa Substation in Bhokraha Narsingh Rural Municipality of Sunsari by pulling the wire only on one side of the tower.

Under package-2, 220 KV substations have been completed and put into operation at Inaruwa in Sunsari and Tumlingtar, Baneshwar and Vasantpur in Sankhuwasabha. Basantpur substation will receive electricity from Tumlingtar and Dhungesanghu substations. The electricity will be delivered to the Inruva substation through the 220 kV transmission line from Vasantpur and will be integrated into the national transmission system.

Under the Koshi Corridor 220 KV transmission line project, substations and transmission lines have been constructed at Tumlingtar, Vasantpur and Baneshwar with the investment of the Government of Nepal and authorities and the concessional loan of the Export Import (Exim) Bank of the Government of India.

The electricity generated from the hydropower projects being built on the Arun and Tamor rivers and their tributaries will be connected to the Inruva substation through the Koshi Corridor 220 kV transmission line. The Koshi Corridor has been constructed to connect the electricity of the hydropower projects to be built in Bhojpur, Sankhuwasabha, Tehrathum and Taplejung in Koshi province to the national transmission line.

Through the Koshi Corridor transmission line project, about 1,000 MW of electricity can be transmitted from Tumlingtar to Basantpur, about 1,000 MW from Dhungesanghu to Basantpur and about 2,000 MW from Basantpur to Inaruwa. Koshi Corridor is the longest distance 220 kV transmission line of Nepal so far.