“…On the other hand, compared to the horizontal axis turbines, they have lower efficiency, significantly lower starting torque and suffer from cyclic loading. Even though several designs have been proposed, few have reached the prototype phase, most of them for rivers (Miller & Schaefer, 2008;Kahn, Iqbal, Quaicoe, 2006;Salter, 1998;Darrieus, 1931).…”