Minimal effects are measurable in close proximity to the ground
Meteorologist Stefan Emeis estimates the nocturnal warming of the air near the ground in the vicinity of wind farms to be significantly lower, at approximately 0.05°C, as he explained to the Bavarian broadcaster Faktenfuchs. The calculation is as follows: a wind turbine can increase the surface temperature in the immediate vicinity by around 0.5°C on a clear night. The relative humidity near the ground drops by around five to ten percent. However, as this effect only occurs in around 10 percent of nights (10 percent of 0.5 degrees), Emeis estimates the warming of the air near the ground at around 0.05 degrees on average for the entire year.
Clouds and rain form at high altitudes
And what about the rain? This is another area where the critics are not quite right. Although moisture is redistributed, it is not absorbed, so no water is lost.
In addition, our weather is created in completely different dimensions and heights. Modern wind turbines are around 250 meters high. Rain clouds usually have their base at 200 to 1,000 meters above the ground. This means that they can actually reach as high as low-hanging clouds. However, the precipitation-forming processes take place much higher in the upper parts of the cloud, in the temperature range below -20°C and, therefore, at an altitude of around six kilometers.
Basically, our weather is determined by areas of high and low pressure. Wind and rain occur when the air pressure is low. However, a low-pressure area in Europe typically has a diameter of up to 2,000 kilometers and a lifespan of up to a week, explains meteorologist Astrid Ziemann from the Institute of Hydrology and Meteorology at TU Dresden on MDR. The associated precipitation processes also take place on larger scales. She, therefore, described the effects of wind farms on large structures in the atmosphere as questionable.