Numerical investigation on the dynamic responses of three integrated concepts of offshore wind and wave energy converter

Abstract To achieve a better utilization of ocean space and energy, three integrated concepts of column-type wind turbine and heave-type wave energy converter (WEC) have been proposed for deep, intermediate and shallow water depth conditions, respectively. The WECs are installed on the wind turbine columns, then wave energy can be absorbed by power-take off (PTO) system through the relative heave motions between wind turbine column and the WEC. The spar-type floating wind turbines with long and short floaters are considered for deep and intermediate water depth conditions whereas a fixed-type wind turbine is considered for the shallow water depth condition. On the other hand, the WECs are torus-shaped heave-type devices, with dimensions and configurations the same for the three concepts. Numerical models are established for all the three concepts. The combined systems are subjected to various wind and wave conditions. The dynamic response analysis is carried out, and the responses including motions, forces and power, are compared among them. The results show that significantly different dynamic responses of the three concepts under environmental actions are observed.