13. Januar 2025
An international team of researchers has investigated the impact of wind energy on the environment, society, industry, and law. A total of 24 co-authors from scientific institutes in seven European countries were involved in the investigation, including a team from Jülich Systems Analysis. More than 400 individual studies were included in the analysis. The review paper was published in the renowned journal Joule and provides guidance for future studies and political decisions
"The study looks at the impact of wind energy on the systems in which it is integrated," explains lead author Russell McKenna, Professor of Energy Systems Analysis at ETH Zurich and Head of the Laboratory for Energy Systems Analysis at the Paul Scherrer Institute. Almost all of the co-authors of the study are involved in the three-year project known as WIMBY ("Wind In My Backyard"), which is funded by the European Commission. As part of this project, the researchers conducted a holistic analysis of wind energy.
In terms of the environment and the climate, for example, they looked at the impact of wind farms on the local climate and the end-of-life scenario of rotor blades, which are very difficult to recycle. For socio-economic systems, the researchers identified the local costs and benefits of wind turbines. With respect to the political and legal system, there is the issue of what happens if the supply chain is interrupted for geopolitical reasons. In total, over 400 studies were evaluated.
New approaches to recycling
The researchers found some surprising results. For example, infrasound, low-frequency noise, is often cited as a problem for the population because it can cause irritation and even lead to the vibration of objects in houses. "However, there is only one research study we know of that has examined a specific wind turbine, and that was about three decades ago, when the first prototypes were just being built," says McKenna. "With today's turbines, there is no longer any demonstrable connection with low-frequency noise, but this has not yet become common knowledge."
One challenge that scientists have identified is recycling. In the next few years, tens of thousands of wind turbines will need to be replaced, the rotor blades of which cannot be recycled. The reason for this is the fibre binder, which makes it impossible to recover the glass fibres. However, there are approaches to avoid this problem in the next generation, as technologies such as pyrolysis can help to recover the blade fibres. For newer rotor blades, the major manufacturers are now using a resin that dissolves at the end of its service life, so that the fibres can be more easily recovered in 20 years. "A combination of approaches is therefore being pursued to recover as much material as possible in the cycle," McKenna says. "Ultimately, such impacts must always be weighed against the positive side effects of wind energy expansion - one of which is the move away from fossil fuels."
A great effort needed to inform the public
The researchers see the greatest need for action in another area: "It is clear that the population's acceptance of wind turbines is crucial, as they dominate the landscape," says McKenna. In general, acceptance among the population is high. But there is often resistance at local level. "It has been shown that acceptance of wind turbines increases when the community benefits, for example, through financial participation in the project or when jobs are created for the local economy," says McKenna. "It's not just about technical jobs - wind farms can also be attractive locations for tourism."
In general, a great deal of effort must be invested in informing the population about the respective advantages and disadvantages of wind energy. "With all energy technologies, a compromise is always necessary," says McKenna. "It is unreasonable to focus on the disadvantages of one technology without considering the alternatives."
Three questions for Heidi Heinrichs and Jann Weinand from Jülich Systems Analysis. They are part of the main team of authors who conceptualized the study.
Your analysis of the impact of wind energy is very comprehensive and covers many different areas. How did you go about it?
Heidi Henrichs: In order to identify the most important factors influencing onshore wind power systems, we first carried out a systematic literature classification. This allowed us to identify and select the relevant studies. In total, more than 400 studies were selected. In the main author team, we then compiled these studies into 14 central categories over several rounds of discussion.
The Jülich team was responsible for five areas: impact on the landscape, impact on the energy system, social acceptance, systems integration, and end-of-life challenges - including the possibility of recycling rotor blades.
The individual aspects clearly influence each other. For example, is there a correlation between the impact on the landscape and acceptance among the population?
Jann Weinand: A number of aspects play a role when it comes to acceptance. Studies have shown that acceptance on a local level can be improved by involving the local population in planning processes, for example, or by minimizing the impact on the landscape. Which measures are ultimately the most effective depends on the local conditions.
In the UK and Germany, for example, onshore wind turbines in beautiful landscapes have tended to be rejected, which is why wind farms have generally been built in landscapes that are considered less idyllic.
While in Germany, good wind resources, i.e. high wind speeds and therefore lower costs per kilowatt hour of electricity generated, do not really correlate with the beauty of the landscape, in the UK the best wind resources can be found in beautiful and remote landscapes such as the Scottish Highlands. This would make optimal planning comparatively more difficult in the UK for this specific planning criterion.
The study proposes a number of solutions for the recycling problem, such as new manufacturing methods and materials for the rotor blades. Will this solve all recycling concerns in the future?
Heidi Heinrichs: The new generation of rotor blades does not solve the problem of existing wind turbines. In Germany, in particular, where landfill and incineration are prohibited, only a few options remain, such as downcycling to filler materials.
Although rotor blades are one of the biggest challenges for recycling, they are not the only ones. There is also the recycling of critical raw materials contained in the permanent magnets of the direct drives, a challenge which also has an important geopolitical dimension due to Germany's dependence on imports. This is not just a problem for wind turbines, but also for other products that use permanent magnets, such as electric motors.
The cross-industry use of permanent magnets further complicates the challenge of material supply, but it also provides an opportunity, as interdisciplinary efforts to solve this problem can create synergies for joint developments. How such cross-sectoral material bottlenecks might affect the energy transition is a subject of investigation as part of my ERC grant for the MATERIALIZE project
Original publication: McKenna R, Lilliestam J, Heinrichs H et. al. System impacts of wind energy developments: key research challenges and opportunities. Joule, DOI: 10.1016/j.joule.2024.11.016
