The following was originally published April 22, 2011 at http://aero103.blogspot.com/2011/04/hydroelectric-energy.html
Hydroelectric Energy

According to the United Nations, two thirds of the world's hydroelectric potential is being used, especially in North America and Europe. China is The world's largest producer ofhydroelectricity (95,000 MWinstalled), followed by the UnitedStates, Canada, and Brazil

SO; WHAT IS THE HYDROELECTRIC ENERGY?
SIMPLY; THE KINETIC ENERGY OF THE RIVERS IS TRANSFORMED INTO MECHANICAL ENERGY BY TURBINES THEN TRANSFORM THE MECHANICAL ENERGY INTO ELECTRICAL ENERGY.
SO WE NEED :

1-Turbine Room: The place where the kinetic energy of the rivers is transformed into mechanical energy by turbines and later into electrical energy by generators.
2-Generator: It transforms the mechanical energy of the turbines into electrical energy.

In brief :
1-Water enters the powerhouse under pressure and is injected into the turbine.
2-The force of the water on its blades causes the turbine to turn.
3-The turbine makes the generator turn, thereby producing electric energy. The water is returned to the river.


Plants :

1-Bypass Plant: Does not have a reservoir. It simply takes advantage of the available flow of water and thus is at the mercy of seasonal variations in water flow. It also cannot take advantage of occasional surplus water.

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2-Plants with Reservoirs: The presence of a reservoir, formed by a containment dam, guarantees a constant flow of water—and, therefore, of energy—independent of variations in water level.

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The water enters the powerhouse and turns the turbines. The generators produce electricity


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For Pumping Plant it has also two reservoirs that In off-peak hours, thewater is pumped tothe first reservoir to be reused.



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"Now about 20 percent of the world's electricity is generated by the force of rivers through the use of hydroelectric power plants. This technology, used since the 19th century, employs a renewable, nonpolluting resource, although the technology's impact on the environment is high."


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