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Wind power forms a crucial part of the transition to renewable energy. But it faces fierce criticism from some parts of society. Is it justified?
As electricity grids rely more and more heavily on wind power, criticisms have become louder.
There are claims that the infrasound they produce can damage your health. And many regard the towering giants to be a blight on the landscape. There are also questions about risks to wildlife and some see inequity in the distribution of profits.
In the face of such headwinds, here's a reality check:
Wind farms undoubtedly alter the landscape. The turbines have become ever taller and the blades now reach lengths of up to 250 meters (820 feet). In good weather, the bright grey structures are certainly visible, but that also applies to other methods of power generation. Coal mining can swallow entire villages and raze forests while high-voltage transmission lines crisscross landscapes, and smoke and steam from towering power plant chimneys and cooling stacks can spread many kilometers into the sky. By comparison wind turbines are clean and don't emit particulate matter, mercury or carbon dioxide.
Compared to the rest of the world, densely populated Germany has a well-developed wind power industry that meets almost a third of its domestic demand. And acceptance of wind energy is high, with 80% of the population saying further development of onshore wind farms is "somewhat important." Around 47% say having a wind farm in the neighborhood is either "somewhat good", or "very good."
By comparison, 62% of Germans are happy to live near a solar farm. That contrasts with 6% for nuclear and 4% for coal power plants.
In high winds, wind farms do become louder. Under full load, noise levels can reach up to 105 decibels at the turbine hub, which is 100 meters high. That's about as loud as an excavator. Within a 250-meter radius, the noise level is around 45 decibels, which is about as loud as a rustling forest or a quiet apartment. And at a 500-meter radius, under a full load, the noise level sinks to 40 decibels, which could be compared to light rain.
The World Health Organization recommends maximum noise level exposure of 45 decibels from wind farms in residential areas. In Germany, the law allows for a maximum of 40 decibels at night, and 55 decibels during the day. That's roughly the same volume generated by regular street traffic. As a result, wind farms in Germany cannot be built too close to residential areas.
Additionally, wind farms emit a very low frequency sound below 20 hertz — known as infrasound. Human ears cannot hear such low frequencies. Such infrasound is also produced by waterfalls and ocean waves, or by machines such as vehicles, heaters, pumps and air conditioners.
Opponents claim that the infrasound generated by wind farms is damaging to human health. But studies show wind farms generate significantly less infrasound than car traffic. In line with the latest research, experts have therefore ruled out damage caused by wind farm infrasound.
From 250 meters, wind farms are no louder than heavy traffic
Wind farms, like roads and buildings, are an intrusion into nature in that they have concrete foundations dropped several meters into the ground. In addition, their blades can kill high-flying bats and birds — a reality opponents often use to argue against this form of renewable energy.
To fight the climate crisis, and to preserve biodiversity, environmentalist groups have called for the expansion of wind power. The transition to renewable energy is "also crucial for the long-term preservation of biodiversity," according to a joint position paper of German environmental groups.
Good planning should avoid environmental damage, as far as possible. For example, wind farms cannot be built in important nature preserves. Instead, suitable locations include previously polluted areas such as former coal-mining sites, intensively farmed land, or even monocultural coniferous forests.
Modern wind farms are less dangerous to bats and birds than previous designs. For one, they are much higher than before, and animals usually fly under the blades. Secondly, there are now new protective mechanisms, such as bat sensors that will halt the rotors if the animals fly too close.
Another technology uses intelligent cameras to recognize large birds of prey, such as high-flying eagles, shutting down the turbines to avoid collisions.
Germany's Nature and Biodiversity Conservation Union (NABU) estimates that wind farms kill more than 100,000 birds each year in Germany. But this is a relatively low figure compared to other hazards.
Glass-covered buildings kill about 1,000 times more birds (108 million) each year than wind farms. Around 700 times more (70 million) die in collisions with cars, trucks and trains, while 20 times more (2 million) lose their lives to power lines and 10 times more (1 million) are killed through hunting. And domestic cats alone are responsible for the deaths of some 60 million birds in Germany each year.
But by far the biggest threat to birds is industrial agriculture, according to NABU. Monocultures and the use of pesticides, has seen the number of insects decline massively, removing a major source of food for birds raising their young. In the past decades in Germany, 13 million breeding pairs of birds have disappeared (15%), leading to 170 million fewer young birds each year.
Wind farms do kill some birds, but the death pales in significance to other dangers
Sometimes the wind simply doesn't blow, meaning the rotors remain idle and no power can be generated. A reliable power grid therefore requires additional forms of energy production and storage.
Norway and Costa Rica have already completely renewable power grids. Alongside wind, they rely on hydropower, geothermal energy, biomass and solar power.
These other renewables can also compliment wind power in other parts of the world. Depending on the location, a different mix of energy sources is possible. In some areas, this requires green hydrogen plants and large-scale batteries.
A large onshore wind farm (6 MW) costs between €8 million and €12 million ($9-$13.5 million) to build, and produces electricity for 4 to 8 cents per kilowatt hour.
The earning potential for wind farms is enticing, with returns of more than 10% possible. Large corporations profit from this, but so do municipal utilities and local cooperatives. However, wind farms can lead to resentment if the local population don't see these profits themselves. Therefore, projects launched by outside investors often fail.
There is a higher acceptance rate when local citizens can invest in the project themselves and have a share in the profits. Such projects can be financed with individual shares as low as a few hundred euros. Another route to success is for a municipality to invest taxes from wind farms into local projects such as kindergartens.
Wind farms with citizen participation exist in many parts of the world, but there are an especially high number in the north of Germany. Rural communities see wind power as a chance to secure new jobs and prosperity.
This article was translated from the original German.