Wind turbines: How does wind generate electricity?
Clean and inexhaustible – wind energy is second only to hydro-electric of the renewable energies used to generate electricity in France.
Since the installation of the first wind turbine in Dunkirk in 1990, the number of wind turbines has continued to grow. There are now 4,500 in France. In Spain in 2013, they were the primary source of electricity, followed by nuclear. Further afield, the wind turbines installed in Europe by the end of 2013 are capable of generating sufficient energy to supply 8% of Europe’s electricity needs!
On land or sea, to each its wind turbine!
Although the majority of wind turbines are installed on dry land, they can also be found at sea. Offshore wind turbines are positioned out to sea, more than 10 km from the coast. There, due to the force and regularity of sea winds, they function more continuously than on land. Due to their greater efficiency, they generate up to 60% more energy than a land-based wind turbine!
Land-based wind turbines are placed in wind farms (or wind parks), covering large areas of land. They can measure from 10 m to 120 m in height, with blades from 5 m to 90 m in length, equivalent in length to more than 5 lorries placed end to end ! The wind needs to blow at a minimum of 10 km/h for the turbine to work. At over 90 km/h, a security system shuts down the turbine automatically. A single 3 MW wind turbine can cover the electricity needs of 2,600 people, including heating.
When rotated by the wind, the propeller sets the alternator in motion. This rotation produces the energy that enables the alternator to generate an alternating current. Located within or close to the mast, the transformer changes the voltage of the current so it can be transmitted by the medium tension lines of the grid.
Wind energy and VINCI Energies
“Renewable energies (EnR) offer new solutions for an ever-increasing energy demand”, explains Jean-Louis Golfier, business unit Manager at Omexom Energies Renouvelables: “For the time being they are complementary to fossil fuels”. For several years, VINCI Energies has been involved in major projects to produce renewable energy such as wind farms. In 2012, the Group, via Cegelec, also contributed in the construction of Turkey’s largest wind park, a wind farm with 52 turbines capable of generating 143 MW. It has also, via GA Gruppe, completed the connection of the North Sea DolWin II offshore wind park to the land network.