6 things to know about offshore wind farms

By ENGIE - 14 April 2022 - 11:35

Energy from the open sea… Thanks to offshore wind farms, this sustainable and inexhaustible energy source is transformed into electricity. Want to know more about this energy that has everyone talking? There you go!


1/ Did you know that a 1 GW offshore wind farm is as powerful as a nuclear plant unit?

Offshore wind turbines often have very high masts and are installed at a distance from coasts, where wind is both stronger and more consistent than on land. The result? The wind turbine will produce much more than if it was on land. Offshore wind turbines power can also reach 15 MW – much more than their onshore counterparts, which in turn have an installed capacity between 2 and 5 MW* (the nominal power is constantly increasing). As such, in the United-Kingdom, an extraordinarily-large park – 280 wind turbines nearly 30 times more powerful than those in Denmark in 1991 – located at more than 120 kilometres from the coast will allow to produce as much electricity as a nuclear plant with several reactors by 2026.


2/ Fixed or floating wind turbines? A question that runs deep…

Floating wind turbines refer to wind turbines that rest on a floating structure directly anchored to the seabed by several lines. Fixed wind turbines are attached to foundations (pile, concrete, etc.), which are themselves fixed to the continental shelf. With a floating installation, it becomes possible to operate wind turbines installed at depths greater than 50 metres, in locations further from the coast.

>> More information on these technologies <<


3/ The impressive size of offshore wind turbines

Offshore wind turbines almost make their land counterparts look like scale models! With blades spanning more than 150 metres in length and a total turbine height of up to 260 metres*, performance is greatly improved. 


4/ Production potential that remains largely unexploited

This technology has a bright future ahead of it! According to the International Energy Agency (IEA), offshore wind farms have the potential to supply close to 420,000 TWh of electricity per year, which is nearly the global demand for electricity in 2040, and would become the most cost-effective source of renewable energy. France has the second largest offshore wind resource in continental Europe after Great Britain, and aims to reach a power capacity of approximately 5 GW by 2028.
The Dieppe-Le Tréport offshore wind farm, which aims to produce an average of 2 000 GWh per year by 2026, will, for example, meet the annual electricity demand for approximately 850,000 people, i. e. approximately two-thirds of the population of the Seine-Maritime department and more than the entire population of the Somme department.


5/ Offshore wind: good news for the circular economy

Is the end-of-life for installations taken into account? Absolutely! They are designed to be recycled as much as possible, much like onshore wind turbines. For example, in the Aude department, during the recent dismantling of France’s first wind farm, ENGIE was able to recycle more than 96% of the components. And that’s just the beginning: the first prototype of a 100% recyclable wind turbine blade has just seen the light of day - the future is all about recycling!  


6/ Birds and offshore wind farms, coexisting in harmony

The installation of offshore wind farms is, in general, potentially good news for birds, particularly those of prey. Several studies are currently being carried out on an international level to precisely study the impact of offshore wind  farms and to analyse the behaviour of birds prior to the construction of a farm. On our projects, such as EFGL (Eoliennes Flottantes du Golfe du Lion) in the Mediterranean, we are working to improve our knowledge of bird behavior and the reliability of surveillance and deterrence technologies. These improvements will be deployed in the future. The British study Thetys for example, which is based on 22 months of observations on the behaviour of seabirds on the Thanet wind farm, shows that birds seem to be able to change their trajectories to avoid the turbines. A win for our avian friends! 


*Source: Windeurope