The construction of the Chilime–Trishuli 220 kV transmission line, which will feed the electricity generated from the hydel projects along the Trishuli River corridor and its tributaries to the national grid, has been completed, accoridng to the Nepal Electricity Authority (NEA).
The 28-kilometre transmission line extends from the Chilime Hub Substation at Thambuchet of Aama Chhodingmo Rural Municipality in Rasuwa to the Trishuli Three B Hub Substation at Pahirebensi of Kispang Rural Municipality in Nuwakot district.
Kulman Ghising, Managing Director of NEA, said that the construction work was completed by the continuous effort of the employees and construction workers even during the public holidays of Dashain and Tihar.
Ghising reiterated that the transmission line was developed to facilitate the flow of electricity from various hydropower projects under construction in Rasuwa, including the 111 MW Rasuwagadhi and the 42.5 MW Sanjen, which are now in the electricity production phase.
“The project faced significant challenges due to the geographical difficulties of the mountainous region, lack of roads, and the need to transport construction materials via porters and mules,” said Ghising. “Additionally, landslides, conflicts related to the use of forest land, local opposition, Covid-19, and adverse weather conditions added to the difficulties for the timely completion of the project.”
Mentioning plans for the Chilime-Kerung cross-border transmission line for electricity trade with China, Ghising emphasised that it will be through the Chilime–Trishuli.
As part of the Chilime-Trishuli 220 kV project, the construction of the Chilime Hub and the Trishuli Three B Hub substations at 220/132/33 kV has already been completed. The electricity coming from the Trishuli Three B Hub Substation will be integrated into the national grid via the Trishuli-Kathmandu 220 kV transmission line.
The transmission line consists of 76 towers, situated at elevations ranging from 680 to 2600 metres above sea level. Of the total, 33 towers required construction of separate access roads.
According to Thark Bahadur Thapa, Director of NEA's High Voltage Grid Department, more than 20 kilometres of access roads have been constructed in the course of developing the transmission line. Construction materials and equipment were transported by nine helicopters, in addition to using workers and mules, Thapa added.
From Tiru in the Uttargaya Rural Municipality-1 to Siruchet in the same ward, a 1235-metre long cable has been installed. In the section above the Mailung River (Mailung Crossing), drones were used to assist in the pulling of cable.
Under this transmission line, the Chilime-Mailung section consists of a 20-kilometre double circuit, while the Mailung-Trishuli Three B Hub section includes an 8-kilometre four (multi)-circuit line.
The multi-circuit line will transmit the electricity produced from the 216 MW Upper Trishuli-1 hydel project, being constructed under the lead of Korean companies, to the national grid. The 60 percent of the cost for developing the multi-circuit line will be borne by Upper Trishuli-1, according to NEA.
The estimated cost of the Chilime-Trishuli project, when its construction began in October, 2016, was around 65 million euros. It is funded by the Government of Nepal and NEA, along with a grant from the German Development Bank (KfW) and a concessional loan from the European Investment Bank (EIB). The European Union has also supported the construction of the project.
