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present:
Wind Energy
“Whoosh, whoosh” that is the sound of wind hitting against the sails on the Santa Maria in 1492. Without the power of the wind, Columbus would have never been able to reach his destination. There are lots of things that are powered by wind. For example, kites and airplane gliders are propelled by wind. One thing wind gives us that we need and use everyday is electricity. Making electricity from wind energy is not as easy as flying a kite. It has more steps and is a lot more complicated. First the power companies have to find a place where the wind blows hard, constantly, and also not many people live there.
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Then they build a turbine there. A turbine has many parts inside it. A low speed shaft, gearbox, and a generator are some of the things that a turbine contains. The generator is made up of a chamber whose walls are lined with magnets; a coil of wire spins inside magnets and makes electricity. A turbine usually has two to three blades and comes in a variety of sizes. |
One of the biggest turbines in the world is in Hawaii. It stands twenty stories high and each blade is half as long as a football field {3}. The most common turbines sold are in the range of 600 KW to 1 Mw, which is enough to supply electricity to 600 to 1,000 modern homes {KW = Kilowatts and Mw = Megawatt} {4}.
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After the turbine is built, it works on its own. Blowing wind spins the blades on a wind turbine, just like a large pinwheel. The blades are attached to a hub that is mounted on a turning shaft. The shaft goes through a gear transmission box where the turning speed is increased. The transmission is attached to a high-speed shaft, which turns a generator that makes electricity. When the turbine is producing electricity the blades are spinning incredibly fast. If the wind gets too strong, the turbine has a brake that will keep the blades from turning and being damaged. |
| Turbines are built in windy places. On the map to the right it shows that the red and orange spots are the best places to put a turbine because that is where the wind blows the most. The purple places are not windy at all and it would be a waste of money to put one there because there is little wind for the turbine to work. |
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As it shows on the map, the coast and the low Rocky Mountains are the best places to put a turbine, because the coast is by the ocean where it is very windy, the low Rocky Mountains are high ridged and that is where it is windy too. One of the disadvantages of wind energy is that there are only a few places in the world that wind blows all the time.
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Some of the good features of wind energy are that it is healthy for the environment {no pollution}, is renewable, after the turbine is built then the wind is free {2}, the cost is dropping as time passes, quick installation (once a site has been selected wind turbines installation can be completed in months), compared to years for a nuclear plant {1}, and also wind turbines are very tall so wild animals won’t usually get hurt by the blades.
The wind is an awesome force of nature and scientists are learning more and more about how to control its force to benefit our society. Using wind energy as a renewable energy source rather than fossil fuel helps the environment by reducing pollution. It is more economical to produce and is much safer than an oil refinery or a nuclear power plant. Wind energy is growing in popularity and it looks like that in the near future, it will be the one of the most used alternative energy sources of the 21st century.
Sources
1-“Health, wind energy”, Salem Power Plant Health Link
http://www.healthlink.org/windproscons.html
2-“Wind Turbines ”Renewable Energy Technologies and their Pros and Conshttp://lomaprieta.sierraclub.org/greenpower/renewabletech.htm#W%20%20indind
3- “Quick Facts about Wind Energy”, Wind Energy Program
http://www.eren.doe.gov/wind/web.html
4-“Renewable energy technology fact sheet”, UNEP Division of Technology,