Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy. Once a hydroelectric complex is constructed, the project produces no direct waste, and has a considerably lower output level of the greenhouse gas carbon dioxide (CO2) than fossil fuel powered energy plants. Worldwide, an installed capacity of 777 GWe supplied 2998 TWh of hydroelectricity in 2006.[1] This was approximately 20% of the world's electricity, and accounted for about 88% of electricity from renewable sources.continue..

The theory is to build a dam on a large river that has a large drop in elevation (there are not many hydroelectric plants in Kansas or Florida). The dam stores lots of water behind it in the reservoir. Near the bottom of the dam wall there is the water intake. Gravity causes it to fall through the penstock inside the dam. At the end of the penstock there is a turbine propeller, which is turned by the moving water. The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generator that carry electricity to your home and mine. The water continues past the propeller through the tailrace into the river past the dam. By the way, it is not a good idea to be playing in the water right below a dam when water is released!continue..

Hydroelectric power or hydroelectricity is electrical power which is generated through the energy of falling water. This method of energy generation is viewed as very environmentally friendly by many people, since no waste occurs during energy generation. However, hydroelectric power can have a profound impact on the surrounding environment, leading some people to question the promotion of hydroelectric power as a method of clean energy generation.continue..

Most hydro electricity comes from dammed water which is released to drive a water turbine and generator. The energy created by the moving water depends on the volume released, and on the difference in height between the water source and the turbine. The difference in height between the source and the turbine is called the head. The amount of potential energy which can be harnessed from the water is proportional to the head. To obtain very high head, water for a hydraulic turbine may be routed through a large pipe called a penstock..continue..

1. Once a dam is constructed, electricity can be produced at a constant rate.
2. If electricity is not needed, the sluice gates can be shut, stopping electricity generation. The water can be saved for use another time when electricity demand is high.
3. Dams are designed to last many decades and so can contribute to the generation of electricity for many years / decades...continue..

Stock photos of different kinds of hydropower plant..continue..

Hydroelectric power plants convert the hydraulic potential energy from water into electrical energy. Such  plants are suitable were water with suitable head are available. The layout covered in this article is just a simple one and only cover the important parts of  hydroelectric plant.The different parts of  a hydroelectric power plant are

(1) Dam
Dams are structures built over rivers to stop the water flow and form a reservoir.The reservoir stores the water flowing down the river. This water is diverted to turbines in power stations. The dams collect water during the rainy season and stores it, thus allowing for a steady flow through the turbines throughout the year. Dams are also used for controlling floods and irrigation. The dams should be water-tight and should be able to withstand the pressure exerted by the water on it. There are different types of dams such as arch dams, gravity dams and buttress dams. The height of water in the dam is called head race...continue..


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