In times of climate change and power shortages, renewable energies are considered a key technology.
But in Dachau, a wind turbine has to stand still for hours at night.
The reason?
Real-existing, but also suspected bats.
Really true.
Munich – How often and how long does a wind turbine have to stand still at night to protect bats?
The Bavarian Administrative Court dealt with this question yesterday in Munich.
The brickworks Hörl + Hartmann from Dachau had complained because their almost 200 meter high wind turbine had to stand still for hours at night from April to November - so that their rotor blades didn't kill bats flying around.
According to the brothers and managing directors Matthias and Michael Hörl, the system generates around 7.5 million kilowatt hours.
"If the system were to run all night, it could be an estimated two to three million kilowatt hours more," says Matthias Hörl.
Converted, that's a lot of money that the family business loses because no energy is generated that can be consumed by the company or fed into the power grid.
The Hörls estimate that they lose 300,000 to 400,000 euros a year.
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The wind turbine, which switches off at night to protect the bats, is located in Dachau on the Hörl+Hartmann company premises.
© Christian Fischer
The wind turbine has been on the Dachau site since 2016.
Combined with photovoltaics, the company can cover its own energy needs for the whole year.
Hörl+Hartmann is prepared for the energy crisis.
Matthias Hörl is still annoyed: "Nuclear and coal are frowned upon and yet there are still such idiotic laws that prevent existing alternative energy sources such as our wind turbines from being fully exploited.
The energy transition will never succeed in this country.” He explained that to the judge today.
"It's not okay for us to fight with these restrictions when it comes to renewable energy because species protection is unquestioningly cited as the reason."
Dachau: The dispute over the wind turbine becomes a posse - and ends up in front of the Bavarian Administrative Court
From the beginning, the district office stipulated that the wind turbine had to stand still at night from April to November.
“It switches off prophylactically one hour before sunset and on again one hour after sunrise,” says Hörl.
"In the worst case, it stands still for 15 hours." And it gets even more complicated: "The system can run at a wind speed of six kilometers an hour, in heavy rain and at temperatures below ten degrees." Because, according to logic, bats will then no longer fly .
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Michael (left) and Matthias Hörl are the managing directors of Hörl+Hartmann.
© Private
The system is controlled by an algorithm based on scientific observation of bat activity around the wind turbine, known as nacelle monitoring.
A microphone is installed in the nacelle of the windmill, which records the ultrasonic waves of the bats.
According to Hörl, the problem is that waves from bats are also recorded that are not affected by the wind turbine at all - from the common pipistrelle, for example, which does not fly that high.
"We have never found dead birds or bats," he says.
"A house cat kills more than the pinwheel."
The court did not make a decision yesterday.
The procedure is discontinued after the operator and the district office as the control authority have reached an agreement.
In the future, the bat data will be collected by a new version of the "ProBat" monitoring system, which will make it possible to at least partially decide between affected and unaffected bat species.
According to the Bavarian Nature Conservation Union, bats keep dying from wind turbines.
Projections assume that a total of around 200,000 animals per year have an accident at the facilities in Germany.
(sco)
