Like wind energy, the flowing water and water stored in huge dams is also a very important source of energy which is known as hydroelectric energy. But, overdevelopment and unrestricted harnessing of water power can have a devastating effect on the local environment and habitation areas.
Hydroelectric power is produced by the natural flow or fall of water. By channeling water that is flowing downhill, the force of the water can be used to turn turbines and via a generator, produce electricity.
Hydroelectricity comes from the damming of rivers and utilizing the potential energy stored in water. When the water stored behind a dam is released its potential, kinetic energy is transferred onto turbine blades and used to generate electricity. Though the initial cost of setting up of hydroelectric power system
is high, it has relatively low maintenance costs and provides relatively inexpensive power.
The power output of the hydroelectric source is determined by the difference in height between the source and the outflow. This height difference is known as the head and the greater the head, the larger the output. For this purpose, very big dams are made on the rivers and other water flows.
Though water is an excellent source of generating electricity, it also has certain limitations: