Why is wind energy slowing down in Germany

Weather Wind turbines slow down the wind

The largest wind farms in Germany are out in the sea off the coast. The scientist Thomas Feuerle therefore undertook 41 measurement flights with his research aircraft. The wingspan of the machine measures 15 meters and is driven by two propeller turbines with 400 hp each. "Most of the time we started from a place on the coast, for example Wilhelmshaven, and flew out over the sea," he says.

As a rule, the measurement flights would have lasted three and a half hours, then the researchers had to go back because they ran out of fuel. She flew around two offshore wind farms in the North Sea several times with the small machine. "In the thought model we already considered that the energy that is taken from the wind has to stay somewhere," says Feuerle.

50 kilometers of braking effect

What is happening up there at a wind turbine? The wind hits the rotor blades and sets them in motion. Wind is air and air is made up of molecules. They hit the wind turbine and are stopped, slowed down and this effect then spreads. According to the study, the braking effect can still be measured at a distance of 50 kilometers, but varies greatly depending on the weather.

Does the slowed-down air have an effect on the weather? "From my point of view, there are no direct effects on the weather and climate. However, it must be considered where further wind farms are to be set up," says Feuerle.

Wind turbines shovel heat down

The Leipzig meteorologist Marc Salzmann does not believe that wind turbines influence the weather either. "Studies have been carried out on wind farms that were switched off for an overhaul. You measured before and afterwards. The changes were measurable but not so relevant that the weather would have changed," explains Salzmann.

According to the researchers, there are already effects. Especially at night, wind turbines would shovel warm air from top to bottom. A field next to a wind turbine then does not cool down as much. Marc Salzmann adds, however, that wind turbines already have an effect on the weather because they do not emit any greenhouse gases such as CO2. In contrast to coal-fired power plants, wind turbines do not heat up the climate.

Could wind turbines slow down storms?

According to the study, wind turbines slow down the wind a little. Couldn't they then also slow down storms? "In the context of hurricanes this was actually a consideration," says the meteorologist Salzman. But: Wind turbines would have to be built to be more stable for this purpose. Currently they are shut down for safety reasons when it gets too windy.