May 5, 2019
The 220 kV double circuit Trishuli-Kathmandu transmission line — Nepal’s first partially underground power line — built to evacuate electricity from hydroelectric plants in the Trishuli River basin is all set to come online this week, said project officials.
Construction crews have finished installing the 45-km-long power line and are ready to test run it as per the electricity authority’s plan to evacuate 60 MW of power to Kathmandu from the Trishuli 3A hydel plant.
“Although the power lines are ready to relay power, minor works related to gantry structures at the Trishuli 3A power house are yet to be completed,” said Phadindra Raj Joshi, chief of the project. “The power plant contractor is working to finish the structure within two days and after that we will be able to bring the transmission line online.”
Gantry structures are used to connect the nearest tower near a substation to electrical equipment in the substation.
The Trishuli-Kathmandu power line is expected to evacuate 30 MW from the Upper Trishuli-3A plant by May 15 and another 30 MW from June.
Officials also plan to connect under-construction Rasuwagadhi, Sanjen, Trishuli 3B and other small and medium scale hydropower projects to the national grid via the Trishuli-Kathmandu transmission line.
According to Joshi, both the transmission line and Trishuli hydel plant project once commissioned will serve as a lifeline to the Kathmandu Valley and maintain the demand-supply equilibrium, particularly during the dry season when power demand is high.
Power will be evacuated from Trishuli 3A powerhouse to Trishuli 3B hub through a 132 kV line and then relayed to Matatirtha sub-station through the 220 kV double circuit line.
Construction of the power lines and underground facility in Matatirtha started in 2012 but was halted multiple times following natural disasters and forest clearance issues.
According to officials, the Trishuli 3A hydropower project will supervise and manage the power lines that will relay power from the Trishuli corridor to the national grid via Matatirtha sub-station.
Out of the total length, 1,309 metres has been constructed underground with a substation in Matatirtha that can house 24 electricity cables.
“The Matatirtha substation is ready to relay power from Trishuli while works are ongoing to connect it to the grid via Bharatpur,” said Joshi.
Both the transmission line and Trishuli 3A hydel plant were built with concessional loan amounting to $114.7 million from China’s Exim bank.
China International Water and Electric Group undertook the transmission line project and raised 140 towers, mobilising around 300 workers to bring the power line online within the revised deadline after the 2015 earthquake.
Earlier, the project had also faced issues in clearing trees at Mahalaxmi Matatirtha Community Forest, and was given the green light to proceed after Minister for Energy, Water Resources and Irrigation Barsha Man Pun made an onsite visit last August.
Source: The Kathmandu Post