Chilime-Trishuli 220 kV transmission line construction completed

KATHMANDU: The construction of the Chilime-Trishuli 220 kV transmission line, initiated to channel the electricity produced by hydropower projects on the Trishuli River and its tributaries into the national grid, has been completed. This milestone project stretches 28 kilometers from the Chilime Hub Substation in Thambuchet, Aamachhodingmo Rural Municipality of Rasuwa, to the Trishuli Three B Hub Substation in Pahirebensi, Kispang Rural Municipality of Nuwakot.

Kul Man Ghising, Executive Director of the Nepal Electricity Authority (NEA), emphasized that employees and contractors worked tirelessly, even during the public holidays of Dashain and Tihar, to finish the transmission line. Ghising stated that the infrastructure is ready to transmit electricity from Rasuwa-based hydropower projects, including the 111 MW Rasuwagadhi and 42.5 MW Sanjen, which are nearing completion.

“The construction faced significant challenges, including building towers in highly risky and difficult mountainous terrain, transporting construction materials such as gravel, sand, tower components, and water by mules or on foot, and dealing with landslides, floods, forest land acquisition issues, and the adverse impact of COVID-19. Despite these obstacles, the successful completion of the line is a major achievement,” Ghising remarked.

He added that the Chilime-Trishuli transmission line would also facilitate electricity trade with northern neighbor China, as it connects to the future Chilime-Kerung inter-country transmission line.

The project includes the completion of the Chilime Hub and Trishuli Three B Hub substations, which are essential for integrating power into the national grid. Electricity from the Trishuli Three B Hub will be transmitted to Matatirtha, Kathmandu, via the Trishuli-Kathmandu 220 kV line. Meanwhile, power generated by the Sanjen and Rasuwagadhi projects will be connected at the Chilime Hub and fed into the national grid through the newly built line.

A total of 76 towers were constructed for the 28-kilometer transmission line, which runs from an altitude of 680 to 2,600 meters above sea level. Thirty-three of these towers were built in areas without road access, requiring the creation of over 20 kilometers of new access roads. NEA’s High Voltage Grid Department Director, Tharka Bahadur Thapa, mentioned that materials and equipment were transported using mules and helicopters, with two towers constructed using helicopter-assisted delivery.

In a particularly challenging section, spanning 1,235 meters between Thiru and Siruchet in Uttargaya Rural Municipality, the wires were strung using drones to cross the Mailung River.

The Chilime-Mailung section of the line covers 20 kilometers with a double-circuit configuration, while the remaining 8 kilometers to the Trishuli Three B Hub were built as a multi-circuit line to accommodate the 216 MW Upper Trishuli-1 Hydropower Project, currently under construction by Korean companies. The Upper Trishuli-1 project will bear 60% of the cost associated with constructing the multi-circuit line.

The Chilime-Trishuli project, with an estimated cost of USD 362.89 million, is financed by the Government of Nepal, the NEA, and a grant from the German Development Bank (KfW), with concessional loans from the European Investment Bank (EIB) established by the European Union. The contract for the transmission line and substations was signed with Pinggao Group of Companies from China in November 2017, and the project commenced implementation in January 2018.