Wind energy uses the force of the wind to generate electricity. Wind turbines are now part of our landscape, and projects are developing quickly. The interest in this energy? It does not emit greenhouse gases, and its resources are almost unlimited because at sea or on land, the wind blows… very often.
Discover, in this file, everything you have always wanted to know about this energy!
Misconceptions about wind energy
Wind energy makes noise!
A common misconception about wind turbines is that they are noisy, hence the fear of some residents when they learn that a wind farm will be set up near their home. Indeed, the first-generation wind turbines were.
Today, they are increasingly silent thanks to technical improvements (reduction in the speed of rotation of the blades, silent precision gears, mounting of the transmission shafts on shock absorbers, padding of the nacelle).
The worry about this often fades after visiting a wind farm.
Wind turbines don’t work all the time!
Wind turbines are installed in areas designed to produce electricity between 75 and 95% of the time.
Sometimes wind turbines do not turn because the wind is too weak or too strong. It is also possible that France’s electricity needs are not large enough and that nuclear power plants, hydraulic energy, and solar energy already make it possible to meet all the needs.
Setting up and dismantling a park consumes a lot of energy!
Wind energy promotes respect for the environment throughout its life cycle (production, use, end of life). Wind energy is, therefore, clean energy:
- Before the construction of the park, the potential impacts on the environment (and in particular on biodiversity) are analyzed, and measures are implemented to avoid, reduce and compensate for them;
- the manufacture of wind turbines, of course, requires energy, but the energy used is returned in a few months when the wind turbine is in service;
- when in use, wind turbines only use wind energy and do not emit any greenhouse gases;
- at the end of the life of a wind farm, a site can be dismantled at any time and in a few days, ensuring complete restoration of the site. The materials used for manufacturing are mostly recyclable. They can be used for the production of other objects.
How wind power works
How to make electricity with wind?
An aerogenerator, more commonly known as a “wind turbine”, is used. Its operation is simple and is inspired by windmills.
The machine consists of three blades (in general) carried by a hub constituting the rotor and installed at the top of a vertical mast. This assembly is fixed by a nacelle which houses a generator. An electric motor orients the rotor so that it is always facing the wind.
The blades make it possible to transform the kinetic energy of the wind (energy that a body possesses due to its movement) into mechanical energy (mechanical movement of the blades).
The wind spins the blades between 10 and 25 revolutions per minute. The speed of rotation of the blades depends on their size: the larger they are, the slower they turn.
The generator converts mechanical energy into electrical energy. Most generators need to spin at high speed (1,000 to 2,000 revolutions per minute) to produce electricity.
It is, therefore, necessary first that the mechanical energy of the blades passes through a multiplier which has the role of accelerating the movement of the slow transmission shaft, coupled to the blades, to the fast shaft coupled to the generator.
The electricity produced by the generator has a voltage of approximately 690 volts. Since it cannot be used directly, it is processed using a converter, increasing its voltage to 20,000 volts. It is then injected into the electricity network and can be distributed to consumers.
Where does the wind come from?
Wind energy is an indirect form of solar energy. The absorption of solar radiation in the atmosphere generates differences in temperature and pressure, which set the masses of air in motion and create the wind.
Wind energy: energy used for a long time
Along with water and wood, the wind was one of the first natural resources to facilitate human life. By mastering the wind’s force, men could grind the grains with windmills. By sailing on sailboats, explorers discovered new lands.
Today, wind energy is used to produce electricity.
Where to place a wind turbine?
Wind turbines can be placed on land (onshore wind). These are wind farms or wind farms. But they can also be placed at sea. This is called maritime or offshore wind power.
Before deciding on the installation of a wind farm, several studies are carried out. The first step is to ensure that the proposed location is suitable for such a project. In particular, he must:
- be sufficiently windy. Ideally, the winds should be regular and sufficiently strong, without too much turbulence, throughout the year. Wind turbines operate for wind speeds between 14 and 90 km/h. Beyond that, they stop for safety reasons. Electricity production varies according to wind speed. It is with winds of 45 to 90 km/h that the wind turbine produces its maximum power;
- not be subject to certain constraints (aeronautical, radar, etc.);
- take into account the natural heritage, in particular, avifauna (animal fauna of birds) and marine fauna for offshore wind power and avoid protected areas (such as reserves);
- not take place in sensitive architectural or landscape sectors (listed and classified sites, remarkable landscapes, etc.).
Wind energy: an energy of the future
Wind energy in full development
To fight against climate change, France must reduce its greenhouse gas emissions. It is committed to achieving carbon neutrality by 2050, i.e., a balance, on national territory, between human emissions by sources and human absorptions by sinks of greenhouse gases.
France relies heavily on developing renewable energies to meet its energy needs.
More wind power for fewer CO2 emissions
In periods when our electricity needs are the greatest (for example, winter evenings during very cold weather when buildings have to be heated), nuclear power cannot satisfy them all.
Other energies take over, in particular, hydroelectric or hydraulic power stations (using water energy) and thermal power stations (which use fossil fuels). The latter produces CO2 by burning fuel oil (from oil).
Thus, replacing the electricity production of these thermal power plants with production from renewable energies would make it possible to no more prolonged use of fossil fuels.
If the objectives are achieved, a third of our energy consumption will come from renewable energies in 2030, a large part of which will come from wind energy.
Finally, renewable energies use local resources. This, therefore, allows energy independence, which is not the case today with oil and gas, which we have to bring in from other countries.