Wind power is a renewable energy produced by the force of the wind. This force is harnessed by the blades of wind turbines that transform it into electricity. The share of wind power in French electricity production could reach 10% in 2020. Its development is aided by the public authorities in the framework of energy transition.
Wind power is a renewable energy that relies on the wind. It is also known as aeolian energy, after the mythological Greek god of the wind, Aeolus. Wind energy was first used by man for navigation, using wind currents to push sailing boats. It is now harnessed by wind turbines (or aerogenerators) to produce electricity. The blades of wind turbines capture the kinetic force of the wind, using a technology similar to that of the windmills once used to grind corn.
How a wind turbine functions
The wind exerts a force on the blades of a rotor and rotates them. The blades drive an electric generator that converts this mechanical energy into electric energy. The electricity produced is then injected into the distribution grid. The operation of the wind turbine is controlled by an anemometer and a weather vane installed on the nacelle. The weather vane controls the orientation of the wind turbine so that the rotor always faces the wind whenever the latter changes direction.
Wind turbines are installed on sites called wind farms. A wind farm can comprise two to several tens of wind turbines. Wind turbines operate at wind speeds ranging from 14 to 90 km/h. They are stopped for safety reasons if speeds exceed 90 km/h.
A wind turbine is composed of four elements:
- The mast, which permits placing the rotor at a height where it will be driven by stronger and more regular winds than at ground level. The mast also contains some of the electric and electronic components.
- The rotor, composed of several blades (generally three) and the nose cone. It is coupled to an electric generator.
- The nacelle, mounted at the top of the mast, contains the mechanical and pneumatic components and some of the electric and electronic components.
- The switchyard, located near the wind farm, links the latter to the electric grid to inject the electricity produced by the wind turbines.
A growing share of French electricity
In the framework of energy transition, wind power will undoubtedly occupy a larger share of French electricity production. According to predictions, this share could reach 10% by 2020. The law on energy transition, voted in July 2015, aims to increase the share of renewable energies (water, wind, sun, geothermal, biomass, etc.) in French electricity production from 14% in 2012 to 23% by 2020, and then to 32% by 2030.
CNR is developing in wind power
More than ten years ago CNR committed itself to diversifying its energy mix by adding wind power and solar power to its historic core business, that of producing hydroelectricity. Since the commissioning of its first wind farms in 2006, at Fos-sur-Mer (Bouches-du-Rhône) and Beaucaire (Gard), CNR has developed, through its subsidiary CN’Air, its wind power assets year by year, either by acquiring existing wind farms, or by building new ones. This has led CNR to expand its activities outside its concession in the Rhone Valley. By end- 2016, we owned 37 wind farms, including 26 outside the Rhone Valley. The total installed capacity of these 37 wind farms is 457 MW.
A capacity planned to grow in France and abroad
CNR has set ambitious targets for the coming years. We aim to increase our potential in wind power and solar power to 900 MW in 2020, including 300 MW outside France, thereby tripling our potential in 2015.