The light and dark side of wind power generation
We have all heard that humans have a significant impact on nature: pollution of the ocean, the atmosphere, and climate change. If we talk about air, one of the leading polluters is thermal power plants that produce energy by burning coal, oil, or gas. They emit soot, carbon dioxide, and other harmful substances into the atmosphere.
It’s no wonder that nowadays, everyone is talking about «green energy»: electricity generated with minimal environmental impact. Today, we will talk about the type of green energy most closely related to the atmosphere: wind turbines.
Getting energy from the air: instructions
People tamed the wind more than 1000 years ago. That’s when windmills appeared: They were used to grind flour, crush ore, and irrigate fields.
Windmill. Lawrence Hookham / Unsplash
Electricity from wind was first produced in the UK in 1887. It’s much more versatile: we get clean energy and use it anywhere for anything.
A modern wind turbine consists of three main elements:
- a tower (wind speed increases with height, so it’s best to go higher)
- blades and internal rotating mechanisms
- an electric generator (which turns rotation into electricity and transmits it to the grid)
Theoretically, the amount of energy a wind turbine produces is determined by wind speed and blade size (the bigger, the better). It is clear that in practice, there are many more variables: materials used, wear and tear on the mechanisms, and weather conditions in the region.
Shaun Dakin / Unsplash
Why switch to wind power?
The main advantages of wind turbines are complete autonomy and zero emissions. Combined with high reliability, the results areimpressive. You install a wind turbine and create energy for many years. You also don’t worry about your energy source running out. The wind on Earth will blow as long as the Sun exists.
The location for installation must be chosen very carefully. Yes, the wind blows everywhere in the world, but the wind conditions won’t always allow the wind generator to work to its full potential, and be economically viable. The ideal place would be the coasts of the seas: the wind is stronger and more stable there than over land. You can open our app right now and see the wind map. Everything is visible to the naked eye!
Windy.app
Another big plus is that the base of the wind turbine is only a few meters in diameter, which means it takes up almost no space. A designated area free of trees and buildings must be created around it, but it is often used for agriculture. Farmers rent this land at special rates, which is profitable for everyone. In the seas, wind turbines do not interfere with anyone at all.
Sounds almost perfect. Any downsides?
Sure. The most unpleasant one is that wind power affects the climate anyway. This is especially noticeable near industrial wind farms, but there is a weak influence from every wind turbine.
Wind turbines have been proven to affect the climate within a radius of a few kilometers. Still, scientists believe that the problem will become global with wind power development. Here are the main effects:
- By capturing the energy of air movement, wind turbines weaken the wind, and the air hangs over the same area longer. The area’s climate develops higher contrasts: the air has time to warm up more in summer, and cool down more in winter.
- The rotation of the blades creates a rarefaction of the air, and can cause condensation of water vapor. «Forced» condensation near the wind turbine lowers the humidity at some distance from the turbine. Because of this, droughts are slightly more common near wind farms, and crop yields can be reduced.
- The air temperature increases around wind turbines, especially at night during calm weather. At night, it is colder near the earth’s surface than at higher elevations. Wind turbines mix the air in the lower atmosphere, preventing the surface from cooling «as it should.» On an average day, it is about 0.5°C warmer near a wind turbine than at a distance.
Wind power has other problems. For example, wind turbines make loud noise in frequencies audible to us and in lowerfrequencies (infrasound). The noise can be heard several hundred meters away from the wind turbine.
Wind turbines are also often blamed for the deaths of animals, mainly birds, which are crushed by the blades. However, studies show that wind turbines kill a negligible number of animals compared to other human activities (like power lines and pesticides on fields).
Also, many people say that wind turbines spoil the landscape. If you don’t like industrial landscapes, wind turbines are unlikely to appeal to you. But then again, compared to a traditional coal-fired power plant, it’s not so bad.
And yet, they are the future.
Like any energy source, wind turbines have their pros and cons. But there is no doubt that wind power is more environmentally friendly than burning coal. Wind turbines don’t require huge quarries and wells; they emit nothing into the atmosphere and take up little space. But their impact on the planet is yet to be thoroughly researched. We need to ensure we are moving in the right direction and not towards a dead end.
Text: Eugenio Monti, a meteorologist and a climatologist
Cover photo: Raimond Klavins / Unsplash
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