Rivers are great potential renewable energy source. The flowing energy have kinetic energy which can be converted to electrical energy and mechanical energy. Hydropower provides over 25% of the world’s electricity. Energy generated from rivers are a fundamental for global and local economics. The full global technical potential of hydropower production is estimated at 4,000 GW. Reliable energy services are the backbone for sustainable development. The gradient of the country’s topography provides ideal condition for the development of hydro-electricity in Nepal. Rivers can be the mainstay for Nepal’s energy crisis and leapfrog towards sustainable development. Nepal ranks 44th in terms of annual water resource availability according to FAO (2003).
The total hydropower potential of Nepal was assessed as 83,500 MW in 1966. A recent assessment on a Run-off River (ROR) basis with 80% efficiency resulted in 53,836 MW energy potential of Nepal.Basin wise, Gandaki, Saptakoshi, and Karnali river basins has potential of 17800, 17008 and 15661 MW respectively at 80% efficiency. While it is estimated that about 42,000 MW is economically feasible hydropower potential.
The hydropower development in Nepal began with the development of 500 kW Pharphing power plant in 1911. Hydropower Development Policy 1992 (amendment in 2001), drove the pathway of hydropower development in Nepal with involvement of private sectors. Till date only a mere amount of nearly 1 GW has been generated in Nepal. Kali Gandaki “A” hydropower plant is the country’s largest hydro-plant of capacity 144 MW. But the forecasts shows energy demand is going to doubled in 2025, needing new power capacity. Government of Nepal has set plans to reach 5 GW total hydropower capacity over the next five years. Chameliya hydropower plant (30 MW), Thapa Khola hydropower plant (13.6 MW) and Madkyu Khola Project (13 MW) are some projects connected to national grids in 2018. There are several ongoing hydropower projects which are set to be completed over next couple of years. 456 MW Upper Tamakoshi project, 60 MW Upper Trishuli 3A and 14 MW Kulekhani II plants are expected to be completed at the end of 2019. Besides, 51 hydropower projects totaling 910.31 MW are under various stages of development.
Challenges for energy production from river are resource assessment, economics, environmental adversity and system design. Compared to other sources of energy, hydropower has environmental advantages.