Offshore wind power is becoming a profitable way to produce vast quantities of electrical power because of the high availability of the resource and progressive decrease of the design and installation costs. The most widespread technology is nowadays bottom-fixed offshore turbines, but studies are being carried to go in deep water, where floating systems are needed. This causes unprecedented challenges in integrated system design, and still a definitive optimal configuration is not present. So different designs, also concerning the turbine, are being studied. One of them is vertical axis wind turbines, because of their lower centre of gravity and upscaling properties.