Nepal Electricity Authority (NEA) has commissioned three 220 kilovolts (kV) substations on the same day.

NEA started the operation of a 220 kV substation each in Sunsari’s Inaruwa, Sankhuwasabha’s Tumlingtar, and Baneshwor on Thursday. The construction of the substations was recently completed. The 220/132/33 kV Tumlingtar and 220/33 kV Baneshwor substations have power transformers of 260 MVA and 60 MVA capacity, respectively.

Similarly, the single circuit transmission line in the Inaruwa-Tumlingtar section of the Koshi Corridor transmission line has been charged at 220 kV and brought into operation. The transmission line is 105 kilometers in length.

Kulman Ghising, the managing director of NEA, said that after the operation of the transmission line and substations, the infrastructure to flow the electricity produced in the hill districts of Province 1 into the national transmission system had been created. Managing Director Ghising also mentioned that following the operation of the 220 kV transmission line and the substations, the voltage in the region has improved, making the power supply more reliable and of better quality.

“In the Morang-Sunsari industrial corridor, when the electricity supply in the region was only through the Sunsari’s Duhabi substation, problems such as tripping and issues in voltage, etc often occurred. Now, since the load of the Duhabi Substation can be moved to the Inaruwa Substation, more electricity can be supplied to the industries, and tripping and issues in voltage can be resolved,” Ghising said.

The 220/132/33 kV Inaruwa Substation has been constructed under the Nepal-India Electricity Transmission and Trade Project with the investment of the Government of Nepal and a concessional loan from the World Bank to strengthen the power transmission and distribution system of the country.

Under the 220 kV Koshi Corridor transmission line project, substations, and transmission lines have been constructed at Tumlingtar, Basantapur, and Baneshwor.

Before the operation of the Inaruwa substation, the Inaruwa-Basantapur-Tumlingtar transmission line was temporarily charged at 33 kV and brought into use. The 66 km transmission line, from Kitingidanda in Sankhuwasabha to Dharan in Sunsari, was charged on 18 August 2021 at 33 kV.

For the improvement and strengthening of the power supply in the Sunsari-Morang Industrial Corridor, a 23 km 132 kV transmission line and a substation from Inaruwa Substation to Biratnagar are being constructed.

The construction of a 400 kV gas-insulated substation (GIS) at Inaruwa is in its final stage. After the completion of the construction of the 400 kV substation, the Inaruwa substation will become another major hub for the transmission system that supplies electricity from east to west of the country.

The electricity produced by the hydropower projects constructed on the Arun and Tamor rivers and their tributaries will be connected to the Inaruwa substation through the 220 kV Kosi Corridor transmission line. The construction of the Basantapur-Dhungesanghu (Taplejung) section and a 220 kV substation in Basantapur is currently being worked on as a part of the Koshi Corridor transmission line to complete them within six months, said Shukra Devkota, the head of the project.

Under the 220 kV Koshi Corridor transmission line project, a 220 kV double-circuit tower has been constructed from Sunsari’s Inaruwa to Sankhuwasabha’s Basantapur, Baneshwor, and Tumlingtar. Only one side of the tower has been stretched.

The transmission line project with an estimated cost of USD 112 million was built with the investment of the Government of Nepal and a concessional loan from the Export-Import Bank of India (EXIM Bank). The Exim Banks provided USD 90 million as a concessional loan for the project.

Through the Koshi Corridor transmission line project, about 1,000 MW of electricity can be transmitted from Tumlingtar to Basantapur, about 1,000 MW from Dhungesanghu (Taplejung) to Basantapur, and about 2,000 MW from Basantapur to Inaruwa.

The Kosi Corridor transmission line is the longest 220 kV transmission line in Nepal to connect the electricity generated from the Arun and Tamor rivers and their tributaries to the national electricity transmission grid of the country.

The Kosi Corridor transmission line project has been constructed to connect the electricity generated from the hydroelectric projects to be built in Bhojpur, Sankhuwasabha, Tehrathum, and Taplejung in Province 1 to the national transmission line. The NEA has signed a Power Purchase Agreement) to connect 516 MW of electricity generated from 28 private sector projects to this transmission line.