Wind energy for power generation

Résumé du document

Currently the first renewable energy (apart from hydro power) used in term of capacity installed throughout the world; wind energy is in constant development [fu]. From the first commercially produced turbines of the 1980s, which were using borrowed technology (aerofoil and blade construction made from aeroplane wings experience, tower design using transmission line poles technology?), to the current turbines designed with tools especially developed for wind turbines (own aerofoil shape, blade structures different from wing structures, new kind of gear boxes and generators?)[1], the wind energy technology has reached maturity and represents now an important market, generating a big amount of money. But the part of electricity produced from wind power is still very low (0.51% in 2003 [2]) and numerous challenges have to be solved, to make it a truly competitive technology to produce electricity. That is what we will try to illustrate in the following work, by first presenting the current use of wind energy, and then by reviewing what are the different issues faced by this technology and how the research tries to get rid of them. Eventually the new possible trends for this technology will be discussed.

Extraits

[...] Wind energy potential: some figures. The resource The only available wind data existing for evaluating the wind energy potential resources come from wind atlases made in the late 80s and giving average wind speed in a given region, at a given height. Then resources assessments are made, taking into account the latest turbine characteristics (as efficiency, hub height the total area not exploitable (because of habitations, traffic, protected spaces ) and even some economic factors. That is why resource potentials are not a fixed quantity, it changes according to the new technological breakthrough, or social factors. [...]

[...] As we saw in the previous parts, the total amount of electricity produced by wind turbines increases at a quite high rate each year (annual growth around 30% for the last decade This power comes from wind farms set up all around the world by different local or global electricity suppliers. Currently, two main solutions exist to set up a new find farm. You can set it up onshore, and then it will be more cost effective and easier to reach for maintenance operation, but you will have to deal with public acceptance, respect some noise regulation and visual impact. [...]

[...] Featuring 30 3MW Vestas wind turbines meters diameters; it has a capacity of 90 Watts Figure 5 Kentish flats wind farm (Source: www.kentishflats.co.uk) Another recent wind farm was set up in Portugal (in Arga) in June 2006. This onshore farm consists in 12 3MW wind turbines, resulting in an overall capacity of 36MW. Note that here the number of turbines has been limited by the Portuguese government, in order to protect wildlife [10]. Other example, the largest Canadian wind farm is located in centennial and began to operate in June 2006. [...]

[...] Indeed the bigger the aerogenerator is, the more power it can produce. And the costs don't increase as much as the size of the turbine As instance the foundations cost, the costs to connect the turbine to the grid or the maintenance costs stay more or less the same whatever the size of the turbine. Producing more power, the use of big wind turbines entails a decrease in the prices of the electricity produced. This trend is confirmed by the major manufacturers whose new products are only multi- megawatt class wind turbines[7] ,as you can see on figure 2 (the example chosen is a Danish company, called Vestas, which is the leader in the wind turbine sector[4]). [...]

[...] The constant and important increase in the number of installed wind farms is a trend which seems to go on. In the global warming context, because of its great ecological qualities, and because of the constant increase in fossil fuel prices, it could become an even more important part in the electricity supply market, thanks to political encouragements as subsidies for instance. But to reach that goal, this technology still needs improvements and research to attain higher cost effectiveness, and easier operability and grid integration. [...]