Hydroelectricity supplies about 20% of the global electricity needs - about 88% of the total renewable energy generated power. Below is an explanation of how hydroelectricity works!
What is hydroelectricity? Hydroelectric energy is falling water from a river that is being forced through an intake under the dam. Then, the force of the water spins a turbine which creates energy which is converted into kinetic energy.
Hydroelectric energy is the result of heat energy from the sun (the water evaporating and raining down again is sustaining a continuous water cycle) and the gravitational forces from the earth (the water falling down). This process is explained in the diagram below.
Where does the continuous water cycle come from? The water cycle is driven directly by solar energy. When the sun heats the water in the ocean, some of the water on the surface is evaporated. The water-vapor rises and when it reaches higher layers of air and is cooled, the water falls down in the form of rain, hail or snow. The water flows in streams and rivers, finally reaching the sea where it again evaporates.
How do humans use hydro power? Hydro power is used by humans as a source of electricity for a range of uses. It can be used for lighting homes, cooling (air-conditioning), manufacturing (to help machines to work) and even transport (such as to power light bulbs).