THE recent trend in wind energy industry, with the increasing deployment of offshore wind farms, has revived the interest in the concept of a vertical axis wind turbine. The scientific, technological and economical challenges of the next generation of wind turbines indicate that a transformative approach is the key for the reduction of the cost of energy. The adaptation of current designs and practice may not be the best solution to face rotor up-scaling, wind farmlosses, floating support structures and improved reliability. In this context, the vertical axis wind turbine has the potential to respond to someof the new environment’s challenges. The new interest has to face a lack of knowledge and proper models; the tendency to adapt both from the more developed horizontal axis wind turbine research field is often inaccurate.@en