Offshore giants: the rise of the towering turbine

Clipper Wind is one of two companies developing 10MW units. The other is Norwegian firm Sway, based in Bergen, which has won a NKr137m (£14.5m) award from Enova, a Norwegian government body dedicated to funding and promoting renewable energy technologies. Both companies are at the design stage, but hope to have full-sized prototypes ready to deploy within the next two years.
However, the two projects are taking very different tacks. Clipper Wind, working from a base in Blyth, Northumberland, is looking at a conventionally styled wind turbine, 145m in diameter, with a solid foundation on the seabed, whose rotors face the wind head-on. Sway, however, is developing floating wind turbines, anchored by a single flexible tether, which have their backs to the wind (see ’Ocean current’, The Engineer, 28 June 2008). Moreover, while the Clipper Wind version will have a geared wind turbine, Sway is developing a gearless direct-drive generator, using technology similar to that currently being developed by both Siemens and GE.