Hydroelectric Power

Essay by dblamp100Junior High, 9th gradeA+, May 2006

download word file, 2 pages 5.0

Hydroelectric energy has several advantages and disadvantages. Some advantages of hydroelectric power plants compared to regular of fossil fuel power plants are that fuel is not burned in hydro plants, so there is no air pollution; the water used is renewable and free, so it can be replenished with nothing really being used. Those are the good things, but now for the few bad. Hydro plants have to have an existing waterfall or an area of land that can be flooded. They also require a large investment of money and time to build. (USGA)

Water turbines are used to spin a shaft which is attached to an alternator. The alternator is the heart of hydroelectric power plants. The alternator is the part that generates the electricity. There are two basic types of turbines, impulse and reaction. Impulse turbines have a high head pressure and a low amount of flow.

When the water is transferred into a pipeline, the water then travels into a nozzle which makes it into a smaller stream of water. That small stream of water is then passed over the turbine blades to turn the turbine. Most of these types of turbines are usably used for small scale applications because they do not need much water. (ABS)

Reaction turbines have a low head pressure but a high flow rate. This type of system does not use nozzles, but instead blades. These turbines operate at a lower speed than impulse turbines but have a greater efficiency. Reaction turbines are normally used in large scale applications, most hydroelectric power plants. Both turbines use kinetic energy to turn the turbine. (ABS) Kinetic energy is the energy form motion. See figures 1 and 2 for a detailed diagram.

The Niagara Falls power plant uses a diversion system. A diversion...