Imagine that a wind turbine works in the opposite way to a fan. Instead of using electricity to make wind, like a fan, turbines use the wind to make electricity.

Almost all wind turbines producing electricity consist of rotor blades which rotate around a horizontal hub. The hub is connected to a gearbox and generator, which are located inside the nacelle. The nacelle is the large part at the top of the tower where all the electrical components are located.

Most wind turbines have three blades which face into the wind. The wind passing across the blades generates rotational movement about the shaft, which connects to a generator where the electricity is made. A generator is a machine that produces electrical energy from mechanical energy, as opposed to an electric motor which does the opposite.

Commercial wind turbines are generally connected together by underground electrical cabling into an array or wind farm. Power is typically fed to the electricity network via an on-site substation and overhead electrical cabling.

The amount of electricity produced depends on the wind characteristics of a particular site and on the capacity of the wind turbine, among other factors. Capacity is measured in kilowatts or megawatts (one megawatt = 1000 kilo-watts). A 2 megawatt turbine at a typical site would produce enough electricity to meet the annual electricity demand of about 1500 households.

Wind turbines do generate some noise but are not noisy. It is possible to stand underneath a turbine and hold a normal conversation. With distance the noise level decreases until it merges with the normal background noise. When it is very windy, the noise of the wind masks the noise made by wind turbines. For more information go to: www.bwea.com/ref/noise.html.

Many public opinion studies have shown widespread support for wind farms. For example, National Wind Power recently commissioned RBA Research to conduct a study of residents close to the Lambrigg wind farm near Kendal in Cumbria. They found a high level of support with 74% of local residents supporting the wind farm, and just 8% opposing it. Of those who opposed the wind farm before it was built, only 1 in 4 still oppose it and more than half actually now firmly support it. For more information about this study go to: www.bwea.com/ref/lambrigg.html.

Wind energy is one of the safest energy technologies and there is currently no record of a member of the public being injured at a wind farm.

The theoretical maximum energy which a wind turbine can extract from the wind flowing over the blades is around 60%. However, more relevant is the nature of the wind resource because this determines the total electricity produced. Wind speeds vary through the year and between years, and there will be periods of calm weather when no electricity is produced. However, wind energy compares favourably in terms of reliability and efficiency with other forms of electricity production, and of course the fuel is free.

Generally, opinion surveys do not suggest that wind farms detract tourists, indeed many wind farms are themselves tourist attractions. Independent research consultants MORI recently conducted a survey of tourists in Argyle and Bute in the west of Scotland, an area where tourism is very important and where the landscape is the major attraction. Of the 307 tourists interviewed, 43% said that they believed wind farms had a positive effect and less than 1 in 10 (8%) thought they had a negative effect. 91% said that the presence of turbines would not make them less likely to visit the area, and in fact twice as many tourists would be more likely to visit because of the wind farms than would be put off! For more information on this report, go to www.bwea.com/pdf/MORI.pdf.

Wind energy is one of the cheapest of the renewable technologies. It is competitive with new clean coal fired power stations and cheaper than nuclear power. The price of wind energy has reduced significantly over the last 10 years and it is well placed to compete with conventional energy technologies in the future, particularly when its environmental benefits are taken into account.

There is increasing agreement within the global scientific community that climate change is occurring, due to rising levels of greenhouse gases within the earth’s atmosphere. Levels of carbon dioxide (the main greenhouse gas) have risen by about 32% in the last 200 years, which is likely to lead over the next century to a range of effects such as more extreme weather events, sea level rises and general shifts in vegetation and climate. While many uncertainties remain, it is clear that the earlier action is taken, the more likely we will be to avoid the more extreme effects which have been identified. Renewable energy technologies, such as wind energy, which produce no carbon dioxide during operation, have an important part to play in tackling climate change.