Wind turbines convert the mechanical energy of wind into electricity. Wind turns the blades, which spin a shaft, which then connects to a generator and produces electricity. Wind turbines can be built on land or offshore in large bodies of water like oceans and lakes.
Based on data from EWEA (European Wind Energy Association), in 2010, there were 70,488 onshore wind turbines and 1,132 offshore turbines across the EU. With technological progress turbines are becoming bigger and more efficient: the same amount of energy can be generated with fewer turbines.
An average size onshore turbine manufactured in 2014 can power annually more than 1,500 average EU households. An average offshore wind turbine of 3.6 MW can power more than 3,312 average EU households.
At present (2014), the development of onshore windmills is more economical than the one of offshore ones. However, in the coming years, as offshore turbines are manufactured on a larger scale, prices will go down, thus making offshore wind energy increasingly competitive.
In 2014, according to EWEA, there are 19.5 MW of wind power capacity installed per 1,000 km of land area in the EU, with the highest densities in Denmark and Germany. Although 25 of the 27 EU Member States now utilise wind power, there is still a substantial amount of wind power capacity available in countries like France, the UK and Italy.
The total installed wind power capacity in Europe at the end of 2012 covers 7% of the EU-27’s annual electricity demand.
Wind provides 26% of electricity produced in Denmark, while Portugal and Spain produce around 16% of their electricity from wind power, followed by Ireland (12%) and Germany (11%).
- Producing electricity from wind energy causes no greenhouse gas emissions. A turbine will yield up to 80 times more energy than the power which was used to build, install, operate, maintain and decommission the power plant (EWEA’s numbers). EWEA estimates that, in 2011, wind energy saved the emission of 140 million tonnes of CO2 in the EU, equivalent of taking 33% of EU cars – 71 million vehicles – off the road.
- As opposed to fossil fuels, wind as a ‘raw material’ has no cost and will always be available.
- Wind power plants take up limited space on the ground, allowing for extended land use in their surroundings (e.g. agriculture).
- The construction time is usually very short – a 10 MW wind farm can easily be built in two months. A larger 50 MW wind farm can be built in six months.
- Unlike fossil fuel and nuclear power plants, wind technology uses very little water to produce electricity. Given the fact that water scarcity is already a pressing issue and will be gravely exacerbated by climate change and population growth, wind energy is a key to preserving water resources.
- Wind is not constant: it is possible to have storms as well as a total absence of wind. If there is no wind, a wind power plant does not produce electricity at all. This is why wind power plants need to be coupled with load following power plants (such as hydropower or bioenergy) and smart grid solutions.
- Wind power stations have also received criticism because of noise pollution. The problem of noise pollution is easy to solve by choosing a suitable location for plant construction and by favouring modern wind power technology. You can consult the review conducted in 2009 by the American and Canadian Wind Energy Association for further information.
- Wind power is also criticized for ruining landscapes (as a matter of taste, this remains debatable). Choosing the appropriate location resolves this issue as well. Most EU countries have identified important landscapes, protected areas and cultural heritage sites, which help power producers finding unobtrusive locations for power plants.
- Wind turbines may affect birds and bats. If a wind power plant is build in a carelessly chosen spot, it can disturb the nesting and feeding of birds. They can also interfere with migration and even cause mortality. However, deaths from birds colliding into wind turbines represent only a tiny fraction of those caused by other human-related causes such as collision with vehicles and buildings. Again, these problems can be avoided by choosing the right locations for wind power production. It is worth noting that wind farms are often subject to an Environmental Impact Assessment. This ensures that their effect on the immediate surroundings, including fauna and flora, is carefully considered before construction starts. Despite its impacts on birds, even bird protection NGOs favour wind power. For instance, many agree that climate change is the single largest threat to birds and wind and renewables are a clear solution to climate change.
You can read more about the environmental impact of wind power in this very detailed article of Wikipedia.
EKOenergy sets criteria to wind power and all other renewables. EKOenergy-labelled wind power comes always from outside of threatened habitats, migratory routes, protected areas and cultural heritage sites.