I led a team that analyzed how a counter-rotating lay-out allows to increase the Annual Energy Production of Vertical-Axis Wind Turbines at high Reynolds number. With a Navier-Stokes solver and a Vortex Panel Method, we computed a 15% efficiency increase on a VAWT with state-of-the-art performance. Finally, we validated our results with wind tunnel tests on a scaled model with our partners at VUB, TU Delft and PoliMi.

A pair of counter-rotating Vertical-Axis Wind Turbines installed on the same floater can lead to capital expenditure (CAPEX) reduction. A tailor-designed control can change the thrust direction of the VAWTs in the horizontal plane such that the cross-wind components cancel each other reducing the overturning moment on the substructure, and thus the floating sub-structure CAPEX, by 35%.

A second research thrust to increase the Annual Energy Production of  Vertical-Axis Wind Turbines at high Reynolds number was to decrease wake loss in wind farms. With CFD simulations, wind tunnel tests and field measurements on large-scale prototypes, my team and I showed that a counter-rotating lay-out allows  to nearly eliminate wake loss in a wind farm of reasonable dimension.