KATHMANDU, Jan 5: The capacity of Dhalkebar substation-- the country's largest substation in Dhanusha-- has been increased. The Nepal Electricity Authority (NEA) has added 220/132, 315 MVA capacity power transformer in Dhalkebar under the Grid Substation Capacity Expansion Project with the investment of the government.

NEA's officiating managing director Hitendra Dev Shakya informed that an additional 315 MVA power transformer connected to the substation was charged at 10:30 pm on Sunday. At present, two 220/132 KV transformers with the capacity of 320 MVA are in operation at Dhalkebar substation. Now, the capacity of the substation has reached 635 MVA. Of the two 315 MVA transformers to be connected to Dhalkebar under the Grid Substation Capacity Expansion Project, one has been already charged while another one is in the process of being connected.

“As soon as the 315 MVA transformer is charged, an additional 100 MW of electricity can be imported from India in winter and supplied to meet the domestic demand. And after the 456 MW Upper Tamakoshi comes into operation, the infrastructure is ready to export electricity that cannot be consumed at home,” said Shakya.

The 400/220 kV Dhalkebar substation, which came into operation a few months ago, has three power transformers with a capacity of 315 MVA each and a total of 945 MVA capacity, which can transmit about 900 MW of electricity. According to Dirghayu Kumar Shrestha, chief of the NEA’s Broadcasting Directorate, if necessary, an additional 100 MW of electricity can be imported through the Dhalkebar-Muzaffarpur cross-border transmission line as per the agreement reached with the Indian side.

“As our infrastructure is not enough, about 270 to 280 megawatts of electricity was being imported from there,” he said, adding, “The Indian side has said that an additional 100 megawatts of electricity can be supplied through the Dhalkebar-Muzaffarpur transmission line.”

The NEA and Indian company NTPC Vidyut Vyapar Nigam (NVVN) have signed a power purchase agreement (PPA) for Dhalkebar-Muzaffarpur transmission line of up to 250 MW during July-November, 350 MW during December-April and up to 200 MW in May-June. The PPA is valid till June 30, 2021.

The Dhalkebar-Muzaffarpur transmission line has been charged at 400 kV. As the 400 kV and 220 kV structures have not been prepared for the flow of electricity in Nepal, the electricity coming from India from the 400 kV transmission line is being converted to 132 kV and later supplied.

The Hetauda-Dhalkebar-Inaruwa 400 kV transmission line is under construction while the Khimti-Dhalkebar 220 kV transmission line is only in operation at 132 kV capacity. Construction work is underway to quickly charge Khimti-Dhalkebar at 220 kV. Electricity generated from the 456 MW Upper Tamakoshi Hydropower Project will be supplied to Dhalkebar through this transmission line.

The electricity of the project will be transmitted in the national grid and the surplus electricity will be exported to India. Electricity from Upper Tamakoshi can be sent from there to East and West for domestic consumption.

In case of excess energy during monsoon, it can be exported directly to India through the Dhalkebar-Muzaffarpur 400 kV cross border transmission line. A minimum of 600 MW can be imported if required in winter and the way will be opened for energy banking between the two countries. Both Nepal and India have agreed to materialize the proposed energy banking.