Since the 1990s, wind turbines have been stirring the wind, and critics.
The last salvo came from Stéphane Bern, who in a column published in the Figaro recently evoked "a deception".
The debate was also revived by a "significant pollution" observed Monday morning off the bay of Saint-Brieuc, where the site of a large wind project is taking place.
A new argument for anti-wind turbines, which include some candidates for regional.
Who decides on the location of the wind turbines?
When it is not a question of "small" wind turbines, it is the prefect who issues a permit. The latter is subject to several stages. If the height of the mast exceeds 50 m, an impact study must be carried out. It includes an environmental component, a health component and a landscape component, according to official texts. A public inquiry is also planned, with a display within a radius of 6 km around the place envisaged for the installation of the wind turbines. If the park must be built in a protected area or if it presents a risk to the good conservation status of a protected species, requests for exemptions can be submitted. An analytical work that takes four to five years according to Paul Neau, expert in the environmental impact of wind turbines, and engineer member of the negaWatt association. "At the end, the prefect says whether or not he authorizesor under conditions, which is often the case, ”he explains.
Is it true that they only run at full speed 25% of the time?
The various interruptions, related to wind and maintenance, do not represent "more than 10 days per year", replies the Environment and Energy Management Agency (Ademe).
And these interruptions have little impact on wind production.
"To compare wind power plants with each other or with other facilities, we use the theoretical notion of load factor (expressed in hours), it represents the average production of the facility reduced to the theoretical production if the latter were in continuous operation. at full power.
The load factor of French wind power is around 21 to 25%.
This corresponds to a wind turbine that runs between 75 and 95% of the time, but not always at full power, ”says the agency.
Are they killers of birds and fish?
They are indeed responsible for the death of certain species of birds.
In 2017, the Bird Protection League (LPO) carried out 37,839 “documented surveys” at the base of wind turbines, which enabled it to find 1,102 dead birds.
The mortality is very variable according to the parks indicates the association: from 0.3 to 18.3 birds killed by wind turbine and per year.
Wind farms located near special protection areas (such as Natura 2000 sites) are the deadliest.
First victims, migratory birds and mainly passerines, which represent about 60% of the corpses found.
Diurnal raptors come in second with 23% of corpses found.
But solutions exist, recalls Paul Neau. “In recent years, cameras have been placed on the masts. They observe flying objects and if it is a bird, they can make a sound to frighten it or even stop. There are also preventive stops for bats, ”points out the expert, who recalls that highways are much more deadly.
On the sea side, fishermen in particular fear that the fish will flee. But according to the French Research Institute for the Exploitation of the Sea (Ifremer), which has been working on this subject for ten years, it is mainly drilling work that disturbs marine mammals. For its part, Ademe recognizes that since offshore wind farms are fewer in number and more recent than onshore wind farms, “the impacts on marine mammals, fish and birds are still difficult to quantify”. The agency ensures, however, that these parks create an effect of "artificial reef", favorable to the reproduction of fish and molluscs. A phenomenon "very clearly observed in parks installed for several years in Denmark and the United Kingdom".
Read also Against wind power at sea, the force of the fishermen of the bay of Saint-Brieuc
Are they harmful for local residents?
Many groups of disgruntled residents have emerged in recent years.
They denounce in particular the effect of noise, and especially infrasound (low frequency sound waves) generated by wind turbines.
Asked about this, the National Agency for Food, Environmental and Occupational Health Safety (ANSES) issued a report in 2017. It considers that nothing "justifies or modifies the exposure limit values to existing noise, nor to extend the sound frequencies currently considered in the regulations to infrasound and low sound frequencies ”.
However, the agency recommends strengthening the information of local residents when setting up wind farms.
Animals from surrounding farms could be affected by their health.
Farmers evoke behavioral disorders, even deaths, in their farms.
A problem taken seriously, and which was the subject of a parliamentary report submitted on June 4 to the Minister of Agriculture.
He calls for further scientific investigation on this subject.
Are they really green?
After 20 to 25 years of existence, the wind turbines are dismantled. And after ? According to some, they are not recycled because of their materials. “90% of a wind turbine is recyclable,” replies Paul Neau. What about the remaining 10%? The crux of the matter lies in the blades. Composed of resin and glass or carbon fibers, they are difficult to recycle and are currently used as fuels. "These are not toxic compounds, they are found in the aeronautics sector", specifies the specialist. Ademe indicates for its part that research work is being carried out to improve their design and promotion.