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Hydroelectric power is probably the cleanest method for capturing energy in the known world. The question is though how does it work; how is the energy converted into electrical power and where does this energy come from? Before we get into that we need to understand how a hydro electric dam works and how it converts flowing water into electricity.

When water from a river flows down hill there is a tremendous amount of energy in this movement. All mechanical energy really is in its most basic form is the power from moving matter. In order to capture this you need to have a generator that is effected by the movement of the water. The generator is used to convert mechanical energy into electrical energy. A generator is made of three main components: the stator, the rotor, and the turbine shaft. This is pretty similar whether you are talking about nuclear power, coal power, or hydro power. The generator uses electromagnetic induction to convert the mechanical force of the flowing water to electrical energy. The basic concept is that when two magnets are moved near each other a charge is created. So by taking one magnet, the stator, and placing another magnet inside it, the rotor, then turning that internal magnet an electrical charge is created. So now that we understand the basics of how the generator works we can look at how flowing water effects it.

The turbine shaft runs down from the rotor to a turbine. The turbine can be simply thought of as a huge fan in the path of the water. As water flows over it the turbine is turned which will then spin the turbine shaft, which spins the rotor inside the stator and takes the mechanical energy of the flowing water and converts it out to electrical energy. The more water pressure you have the more energy can be captured by the generator. Many large dams and hydro plants will have many generator capturing the energy of the water. Hoover Dam is the biggest hydro plant in the United States. When you look at it you can see why. The lake behind Hoover Dam pushes down with all of its weight on a the exit point. Behind that exit point is many generators capturing all of the mechanical energy behind Hoover Dam.

But the question is where does all this energy come from? One of the first laws of physics is that energy can not be created or destroyed only transferred, so what puts the energy into the water? The answer may surprise you if you are not at all familiar with physics, but it is the sun. The sun shines down on the earth and heats up the water in the oceans. This water then rises up into the clouds and rains down onto the earth. In the case of Hoover Dam this is the Rocky Mountains. From here the water then falls all the way down to the bottom of Hoover Dam releasing its energy into the generators into the power plant. If they were not there to capture it this energy would be simply released as some other form of mechanical energy. So all the energy from hydroelectric power actually comes from the sun.



Jason Grace
on behalf of the
BascoTec Internet Limited
Technologie Park 13
33100 Paderborn
Germany

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