Wind turbines from Siemens have developed enormously over the past 30 years. The first commercial machine had an output of 30 kilowatts; the rotor blades were five meters long. This corresponds to a rotor diameter of ten meters. The latest generation of turbines from Siemens has an output of six megawatts and rotor blades with a length of 75 meters, which corresponds to a rotor diameter of 154 meters - the largest in the world. This means that the area for capturing the energy and the output of the wind turbines has increased 200-fold.