This paper presents a summary of the recent work done by the authors regarding the design, construction and test of a novel patented vertical axis and variable pitching blade hydro turbine, named KOBOLD, capable of harnessing clean and renewable energy from marine tidal currents. The KOBOLDturbine, currently moored in Messina Strait, between mainland Italy and Sicily island, is the only existing turbine of this type devoted to exploit tidal currents, and has a 25% global system efficiency. Theoretical analysis and numerical prediction performanceshave been compared and validated with experimental test results on both model and real scale turbines. Moreover, the recent activities in terms of numerical and experimental investigations on vertical axis hydro turbines are presente
