‘Hydro’ or water power refers to the energy of the movement of water being converted into electricity. The general process is power generation by use of water. Hydroelectricity is one of the most mature forms of renewable energy, providing 19% of the world’s electricity consumption from both large and small power plants. The most common type of hydropower uses dam or reservoir for water holding still there are run-off type of project too. Hydro electric power is based on the principle of using falling water to spin a shaft connected to an electric generator. The greater the fall of water, the more power it has to spin. The greater the quantity of water, the greater the number and size of the shafts that may spun and the greater the electricity output. The amount of power produced depends upon following factors:
The Flow [quantity of water passing]
The Head available [Vertical distance of water can be made fall]
Advantages of Hydropower
Non- polluting, clean and environment friendly
A renewable source of energy
Cost of generation, operation and maintenance is lower than the other sources of energy
Ability to start and stop quickly and immediate load acceptance/rejection makes it suitable to meet peak demand and for enhancing system reliability and stability
Long operating life
Cost of generation is free from inflationary effects after the initial installation
Storage based hydro schemes provide benefits of flood control, irrigation, drinking water supply, navigation, recreation, tourism and aquaculture, and
Opening of avenues for development of remote and backward areas
Hydro Power in Nepal
Hydropower so far has been only source of power generation of our country. The growing need of power is increasing day by day while power generation is lagging far behind than demand margin. Nepal is blessed with immense potentialities of hydropower generation. Our country ranks second in water resources after Brazil and posses large potentialities for hydropower generation. Nepal is gifted with economically exploitable hydro-power potential to the level of 42000 MW of installed capacity out of total hydro potential of 83000 MW. Nepal’s immense hydropower potential needs to exploit in broadening the market that is developing in the domestic and regional areas.
Despite the immense hydropower potential in Nepal, only 40 % of its population have access to electricity including 33 % from NEA grid and 7 % from other alternative source of energy( NPC 10th Plan).
Reasons For Development of Hydro Power in Nepal
Minimal contribution to global warming: Hydropower generation does not generate significant quantities of CO2. Some CO2 is generated during construction, but this is minor and comparable to what would be required to construct any power generation facility.
Clean:Hydropower generation does not generate air or water pollution, although there is a potential for water quality impacts in and downstream of larger reservoirs.
Security:Hydropower development requires large capital outlays. But, once built, they are not dependent on imported fuels and the security issues associated with being a landlocked country.
Stability: Cost of development, construction and operation can be well documented and predicted. Once built, the fuel is free and power generation costs are not subject to fluctuations in fuel or transportation costs. Many hydro projects I am working on are over 50 years old, and several are over 100 years old. Under the right conditions, hydropower facilities can run at low operational costs for 50 years or more providing low-cost, clean electric power.
Technological transfer and self-sufficiency: Within Nepal there is growing institutional knowledge and capacity regarding this sector. Enough projects have proceeded in Nepal to enable Nepalese nationals to complete much of the engineering, environmental and social work elements and analysis. In addition, there is now a large cadre of Nepalese construction workers who have worked with international construction companies and have had critical safety and technical training. As a result, Nepal has a trained work-force ready to work on large construction projects.
Power exports:Nepal has the opportunity to export power, thereby contributing to balance of trade and providing needed revenues for the general economic and social progress.
Potential: Nepal has vast hydropower generation potential that has only lightly been tapped.
Poverty alleviation:Hydropower development, in association with linked development projects, can contribute to poverty alleviation and improved living conditions and health for communities in the project area as well as nationwide.