The goal is to get away from the turbulence found near the ground and to climb up into the Ekman layer, above 100 meters high, where the wind blows continuously. Up there, the forces of nature rage freely, creating enough terawatts to meet the energy needs of the global population hundreds of times over. Or at least that's the theory.
Inland, the "technical trend" toward bigger wind turbines "continues unabated," according to a study recently published by the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES).
A visit to the IWES test center in the northern port city of Bremerhaven reveals what lies in store. The center is home to a next-generation rotary blade: flexible, wobbly even, weighing 30 metric tons and stretching 83.5 meters across.
The mammoth prototype blade is currently at the testing stage. Hydraulic presses and cables bend and buffet the blade millions of times over, simulating the stress exerted by storms and gusts of wind.
IWES meteorologist Paul Kühn thinks that the mast themselves, without the blades, could grow to up to 200 meters high. Anything taller would be unprofitable due to the "square-cube law."
So, might we one day see wind turbines with blades stretching up almost 300 meters into the clouds -- a somber memorial to Germany's nuclear phase-out? Even hip urban fans of renewable energy think that would take some getting used to.
Recent studies by bird protectors reveal how the giant blades chop up the air in brutal fashion. "Golden plovers avoid the wind turbines," says Potsdam-based ornithologist Jörg Lippert. Swallows and storks, on the other hand, fly straight into them. The barbastelle bat's lungs collapse as it flies by. A "terrible future" awaits the lesser spotted eagle and red kite, Lippert says.
German citizens are also having to make sacrifices to meet the ambitious goals of the new energy policy. In England, large wind turbines must be situated at least 3,000 meters away from houses in residential areas. In Germany, which is more densely populated, local planners place turbines much closer to homes. In the southern state of Bavaria, for example, the minimum separation is 500 meters, while it's just 300 meters in the eastern state of Saxony.
In the early days, when everyone was still very excited about clean wind power, some farmers in northerly coastal areas allowed turbines to be erected even 250 meters from their cottages. And then they received large compensation payments when the noise from the rotors triggered stampedes in their pigsties.
But now even those in northern Germany are grumbling. Many old wind turbines are being replaced with new, more powerful ones in a process known as "repowering." Instead of 50 meters tall, these new turbines are more than 150 meters high, have flashing lights on them to prevent aircraft from hitting them and make a lot of noise as they rotate.
The result? Complaints about the noise everywhere.
Legal Turbulence The victims of this "sound pollution" typically have bags under their eyes and a tremor in their voices. They are the movement's martyrs. Klaus Zeltwanger is one such victim. He lives just 370 meters from the turbine in Husarenhof. "It whirrs and it hisses," he says, "and then it drones like an airplane about to take off."
To date, the courts have rejected such complaints. Since wind turbines enjoy special rights, fighting them in court is an uphill battle.