Wave power extraction by Multi-Salter's duck WECs arrayed on the floating offshore wind turbine platform

Abstract

Integrating a floating offshore wind turbine (FOWT) and an array of wave energy converters (WECs) can be suggested as a proper new hybrid concept with the aim of more energy harvesting and lower total energy cost. This paper proposes the new composition of a floating braceless semi-submersible platform and an array of Salter's duck (SD) WECs. First, a comparison of the numerical results and experimental data of the hydrodynamics response of FOWT and the single SD WEC response are presented and discussed. Then, the performance of three-hybrid FOWT-Multi-Salter's Duck (FOWT-MSD) systems with 12SD, 15SD, and 18SD WECs has been investigated under different wave periods and wave heights. In the wave period of 6–9 s, 12SD absorbs more power than 15SD and 18SD. From T = 9–11 s, all three systems have the same absorbed power. For wave periods above 12 s, 15SD and 18SD have higher absorbed power than 12SD. No clear trend was observed for wave periods below 6 s. The effect of wave direction shows that at lower wave heights, maximum absorber power belongs to FOWT-12SD under zero wave direction. In contrast, increasing wave heights leads to a smaller difference between the three-hybrid systems at different wave directions.