Why are wind turbines being debated ?
What are the arguments most frequently advanced by opponents of wind turbines and what strategies for improvement are being considered in order to respond to them ?
“Wind turbines do not continuously produce electricity and do not fully meet the needs of consumers”
One of the drawbacks of wind power remains that it is difficult to predict. Indeed, winds are difficult to anticipate and while a turbine needs an adequate wind to start, it stops working in the event of winds higher than 90 km/h.
However, the drawback linked to the unpredictability of production is common to all forms of energy production: photovoltaics produce more at midday, hydroelectricity produces according to the availability of water and nuclear and thermal installations must be stopped regularly for maintenance operations which can last several months. In the case of wind power, having many wind farms spread over the whole of the territory contributes to the regularity and security of supply because the wind regimes are different depending on the region.
“Wind turbines have a significant impact on biodiversity”
Onshore wind turbines can be presented as a threat to birds and bats. While some wind farms, generally the oldest ones, can indeed have an impact on biodiversity (alteration of habitats, disturbance of species or direct mortality due to collision), there has been major progress in the consideration of biodiversity in the development and operation of wind farms. Before any installation of wind turbines, it is now mandatory to carry out an impact study and then to implement measures to avoid or reduce and, finally, to compensate for any residual impacts. If a wind farm is authorised, it is because its impact on biodiversity has been deemed acceptable and that it does not endanger the conservation of the species. The impact of wind turbines on bats and birds can be significantly limited by a judicious choice of the installation site and by the implementation of “speed reduction plans” (for example, by programming a slowdown or a shutdown of a wind turbine’s blades during “peak hours” of passage of birds or bats, or during the migratory period).
Maritime wind turbines are also criticised for their impact on biodiversity, in particular when wind farms are located in areas where protected species live. Critics point to the destruction of habitats by drilling and the departure of marine species due to the noise generated. It is true that the installation of wind turbines at sea requires a high level of knowledge of the marine environment in terms of its physical characteristics and biodiversity, as well as of existing activities. This is the reason why studies are carried out by the government, RTE (the manager of the public electricity transmission network) and project leaders to respond to calls for tenders, to determine the size of the farms and to set up measures to prevent, limit and compensate for impacts. After being named the winner of a call for tenders, the project leader must obtain various authorisations from the competent authorities before starting construction of the farm. The farm is then operated for a period of approximately 25 years before being dismantled.
“Wind turbines mar landscapes”
Nearly all of the wind turbines currently installed in France have a total height (measuring from the end of the blades) of around 150 meters. In the years to come, their height will have to increase in order to boost their individual output and exploit less favourable areas in terms of wind resources. With this increase in the height of the machines and the growing number of wind turbines in the region, the question of their aesthetic acceptability is a real issue to consider for the future development of the sector. This requires limiting the visual impact of wind turbines on landscapes and increased vigilance in terms of proximity to remarkable nature sites. Today, the installation of a farm is subject to an in-depth examination of the integration of wind turbines into their environment and the proper consideration of the issues associated with their operation, and is in particular the subject of an impact study. The impact study must address the positive and negative impacts of a project in terms of all environmental issues.
“Wind turbines emit background noise”
This noise is due to mechanical vibrations between the components of the wind turbine and to the blowing of wind in the blades. The National Agency for Food, Environmental and Occupational Health Safety (ANSES) considers that the audible acoustic emissions from wind turbines are, very often, “far below those of everyday life.” At a distance of 500 meters, which is the minimum distance imposed by French regulations between a wind turbine and a home, the noise is generally less than 35 decibels (noise of a low voice conversation). Work is underway to stabilise the acoustic impact measurement protocol with a view to systematising its control during the installation of each new fleet.
“Wind turbines pose a recycling problem”
Wind turbines are made of 90% steel and concrete, 6% resin and glass or carbon fibres (contained in the blades) and 3% copper and aluminium. The question therefore arises of their recycling when wind turbines reach the end of their life, the average life of a wind turbine being between 20 and 25 years. In concrete terms, 93% of the weight of an onshore wind turbine is completely recyclable (steel, concrete, copper, and aluminium). The blades (6% of the weight of the wind turbine), on the other hand, are more difficult to recycle; they are incinerated and used as fuel in cement factories. Studies are being carried out to improve their design and promotion. The regulations impose recycling targets, both for wind turbines already installed and for future wind turbines (obligation to recycle 90% of dismantled wind turbines from 2022).
Sources : ADEME; RTE; Ministry of Ecological Transition; www.eoliennesenmer.fr; Novethic
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Wind energy: state of affairs and outlookWind energy is booming in France and now represents the 3rd source of energy after nuclear power and hydraulics. The development of wind energy, like that of other renewable energies, is at the heart of the energy transition and the weight of wind power in the French energy mix is set to increase in the decades to come. If the advantages of wind energy are numerous, it has been the subject of debate for many years and a greater level of acceptance at the local level is a condition for its future deployment.
Wind power, the electricity of tomorrow ?Wind power is now the 3rd source of energy in France. Its weight in the French energy mix is set to increase in the context of the energy transition, with the objective of carbon neutrality by 2050.
Wind power: how does it work?A wind turbine is a device that converts the kinetic energy of wind into mechanical energy using an electrical generator located at the top of the mast. A distinction is made between wind turbines placed on land (onshore wind turbines) and those at sea (offshore wind turbines).
The advantages of wind energyWind energy has the advantage of being unlimited and clean. It also brings positive economic benefits through job creation and income generated at the local level. 73% of French people have a positive image of wind energy.