The Department of Electricity Development (DoED) has planned to develop Sunkoshi-II (1,110 MW) and Sunkoshi-III (536 MW) projects as pumped-storage projects for the first time in Nepal.

DoED officials, however, said a Detailed Project Report (DPR) will suggest feasible and appropriate modality for project development.

In a pumped-storage project, water is pumped from lower elevation of the reservoir to a higher elevation during the off-peak hour of electricity demand when the cost of electricity remains low.

During the period of high electricity demand, the stored water is released to lower reservoir to produce electricity. In the process, the power plant itself becomes electricity consumer for pumping water, but it enables the plant to spend less in pumping water for electricity and charge higher during the peak hour.

As per the plan, water will be pumped from the reservoir of Sunkoshi III, which will remain below the Sunkoshi River, to Sunkoshi III during the off-peak hour and release the stored water during the peak hour.

This modality is expected to help address power demand during winter. “There is not a single pumped-storage type project in the country, so we have planned to develop these two projects under this modality,” said DoED Director General Dilli Bahadur Singh.

Currently, DoED is preparing to carry out a DPR for the projects. The Asian Development Bank (ADB) recently signed a loan agreement with the government to fund the DPR. The DoED has been named implementing agency in the loan agreement worth Rs 600 million.

DoED spokesperson Gokarna Raj Pant said they plan to start the DPR as early as possible. “We hope the DPR will start this year,” he said. The DPR for Sunkoshi III Hydropower Project is expected to complete in next two years.

Officials at the Nepal Electricity Authority (NEA) say the Sunkoshi III project can be completed by 2021 if construction starts immediately after the DPR.

Located some 60km away from the Capital, the project is considered among the 10 best reservoir projects, according to a study carried out by the Japan International Cooperation Agency (JICA) in collaboration with the NEA.

The estimated cost of the project is Rs 100 billion. According to NEA, the Central Development Region, which also includes the Kathmandu valley, consumes 50 percent electricity produced in the country. And, the project is expected to address power demand in the region.