Wind energy
Introduction: Wind turbine was built on the idea of the windmill. It is a tool to produce green and clean electricity, based on the power of the wind. There are three types of wind turbines: -the ground wind turbines which is approximately 100m high. -the offshore wind turbines (sea wind turbines). They are approximately 75 m of high. -and the domestic wind turbines (wind turbines at home). They are approximately 35m of high. A wind turbine consists in a mast which maintains a propeller, usually made of three pales, measuring between 5 and 90 meters of diameter, in height, depending on the type of wind turbine.
Offshore wind turbines
Ground wind turbines
Domestic wind turbines
Functioning of a wind turbine : A wind turbine produces some electricity thanks to the strength of the wind. All wind turbines work in a similar way. With the strength of the wind, the so-called propeller rotor starts up, and begins turning. The rotor is situated at the top of the mast because winds blow more in height. The propeller pulls an axis in the nacelle, called tree, connected with an alternator. Thanks to the energy supplied by the rotation of the axis, the alternator produces an alternative electric current. A transformer situated inside the mast raises the electric current tension produced by the alternator so that it can be more easily transported in lines with average tension of the network. To be able to start, wind turbine needs a minimal wind speed: approximately 10 to 15 kilometers per hour. For reason of safety, when the wind exceeds 90 kilometers per hour, wind turbine stops. The maximum speed is of 50 kilometers per hour.
Wind turbines in the world and in Reunion Island : In the world, in 2007, we counted approximately 50'000 wind turbines, with nearly 600 in France. We can find wind turbines in fields, exposed to windy places. And even at sea, there are wind farms. In France we find them especially in the North, in the Northwest and in the South. In Reunion, we count approximately 84 wind turbines; the biggest farm is situated in "Ste Suzanne" with 37 wind turbines, the other park in "Ste Rose" with 23 wind turbines. There is also a park under construction situated near the "east river" which will contain approximately 15 machines. In 2007, the company in charge of these farmss obtained the planning permission for a new park which will be located in "Ste Marie" on which will be built 9 new wind turbines. All the wind turbines in Reunion are ground wind turbines.
Wind turbines farm of Sainte Suzanne
Specificity of wind turbines in cyclonic environment The specificity of the wind turbines located in cyclonic area, such as La RĂŠunion, is that they are guyed with cables and metallic wires. So in case of a cyclon, we lay them down and so they are not broken by the devastating force of the cyclon. It is also easier to fix them in this case, when they need repairs, because they are laid down at ground level. It is thus less expensive to care and maintain.
Students of the project visited the wind farm of Sainte Suzanne –March 4, 2014
Wind farm of St. Suzanne The company owning the wind farm in Reunion island is called Aérowatts. There are approximately € 1.6 million turnover There are 37 wind turbines located on 40 000m ² of land and only 4 Hectars are used. Wind turbines are positioned according to the strength and direction of winds. There are 450 m distance between wind turbines and the first habitations for they can be noisy. Wind turbines installed in Sainte Suzanne are 55 m high and 32 m in diameter. They support up to 90 km / h wind speed, and as we can see from the photo, the installed cables are used to sleep when the wind storm. A wind turbine St. Suzanne produces kwtt 275 / h, all wind farm producing 10,175 megawatts which can power 16,000 homes (more than half of the town of Sainte Suzanne)
Advantages and inconvenients: At the moment, wind turbines present no danger. Some have been in activity for almost 20 years and accidents are rare (a wind turbine can exceptionally fall down). The main advantage of wind energy, it does not pollute, it replaces the means of electric production which pollute. Wind turbines do not reject gas, nor dangerous substances for the environment and health. They thus pollute less. But there is a price for "non-pollution" : -The cost of manufacturing and installing a ground wind turbine is about 1'000 euros by kilowatt, that is 1 million euros the megawatt. -Offshore wind turbines are 2 to 4 times more expensive because there are more technical difficulties for wind turbines at sea. -Domestic wind turbines cost between 10 000â‚Ź and 90 000â‚Ź, which can be really expensive for individuals looking for green electricity.
A field of wind turbines
Conclusion: To conclude, wind energy is a clean way to produce electricity, but with high costs which needs to be compared to the electricity needs, to be sure it is profitable. Some people dislike wind turbine, saying that it disfigures the landscape. I personally think that it is important to have green electricity, such as solar panels and wind turbines, and I think that wind turbine is quite beautiful, although a little too noisy to live nearby. .
Visiting Sainte Suzanne wind farm in 4, March 2014