Huge offshore wind turbines are coming to market. Each turbine can generate 7-8 MW, enough for 4,000-5,000 homes. The SCD 8 MW behemoth is pictured. It has a rotor diameter of 551 feet and an innovative two blade design, which makes transporting and assembling easier, plus the gearbox is smaller. The blades lock into place horizontally when winds are too high or to allow a helicopter to land on top.
The advantages of two-bladed rotors are for a start the much lighter rotor weight of approx. 70% that of a comparable three-bladed rotor, less torque and consequently a smaller gearbox, the hub design is simpler to produce, there are only two pitch systems and above all there is a noticeable drop in assembly, transport, installation and maintenance expenses. Especially offshore applications are simplified due to the only one turbine lifting stroke. For regions with tropical cyclones, the ultimate loads can be reduced considerably through the horizontal parking position. Furthermore, this parking position makes it possible to install a helicopter landing pad.