With a length of 75 meters, Siemens has built the longest rotor blades of their kind currently in test mode. The giant components made of fiber glass will be used by Siemens' new offshore wind turbine generation with a capacity of 6 megawatts (MW). They are already installed on the second prototype of Siemens' 6-MW offshore wind turbine, which was erected in Denmark's Oesterild in 2012. Each rotor has a diameter of 154 meters covering 18,600 square meters, which is the size of two and a half soccer fields. The tips of the blades move at up to 80 meters per second, or 290 kilometers per hour. The huge rotor was made possible by special technologies that enable Siemens to make extremely strong yet lightweight structures.