Coming up
The next round of offshore turbines appears to favour the 5-7MW class, with several 6MW-class machines in development. While most will be direct-drive, some will be geared models, and a mix of medium and high-speed.
While all those listed below have three blades, two-bladed designs are being considered by Dutch 2-B Energy, Germany's Aerodyn and UK-based Condor Wind Energy, which is developing an unusual 5MW medium-speed upwind offshore turbine with an 8-pole induction generator, a teeter hub and active yaw control.
Future plans of note include GE's 15MW turbine with high-temperature superconductor or HST generator and a vertical-axis 10MW Aerogenerator X, being a Darrieus rotor variant characterised by a huge V-shaped rotor.
Finally, price development and future availability of rare earths used for wind-turbine generator permanent magnets could heavily influence the growing popularity of direct-drive PMG as the drive system of choice.
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