Hydroelectricity / hydel power is electricity generated by the gravitational force of falling or flowing water. It is the most common form of renewable energy. Almost more than 15% of global electricity is generated through hydel power.
The hydroelectric power is generated from the potential energy of water stored in reservoirs bound by the dam at higher altitude the flowing water drives the water turbine and generator large pipe delivers water to the turbine. The quantity of power produced depends on the volume and difference in height between the upstream and the downstream destination. This height difference is called the lead.
Thus, amount of potential the energy of water is proportional to the head.
India is the 7th largest producer of hydel power. National hydroelectric power corporation (NHPC), northeast electric power company (NEEPCO), still jail Vidyut Nigam (SJVNL) Tehri hydro development of hydroelectric power in India.
- The cost of hydroelectric is lower than a source of renewable electricity.
- Low CO2 emission than thermal powered energy plants.
- Solid wastes are not produced.
- Reservoirs created can be used for another purpose like irrigation, aquaculture, water sports etc.
- Ecosystem damage and loss of land as large area are submerged due to the required reservoir this results in evacuation and relocation of human settlement.
- Plant material in flooded area decay in an environment and form methane, a greenhouse gas.
- The intermittent opening of turbine gats results in fluctuations of river flow.
- The dam holds large volumes of water a failure due to poor construction, natural disasters or sabotage can be disastrous to downstream settlements and in infrastructure.
- Reservoirs serve the dual purpose of storing water for power generation as well as irrigation, aquaculture, water sports etc.
- Large-scale power generated through large dams can be used for industries.
- Small-scale hydel schemes can be used for supplying power to nearby locality.