Quantifying the Influence of Motion Damping on Co-Located Wind and Wave Energy Devices

Abstract

Offshore renewable energy holds the potential to satisfy growing demands for global, clean energy production. The co-existence of offshore wind and wave energy conversion technologies presents a compelling opportunity for sustainable energy generation at sea. This paper investigates the integration of a co-located point absorbing wave energy converter (WEC) with a monopile supported offshore wind turbine (OWT). Numerical simulations were validated with experimental data and were then used to investigate the hydrodynamic interactions of the two renewable energy systems, addressing the influence of WEC motions and damping on OWT wave loading. The full-scale geometry of the WEC and OWT were sized according to conditions at the proposed Star of the South wind farm in Gippsland, Victoria, Australia. The study found that the WEC’s heave and surge degrees of freedom are highly influential, with a 33% reduction in surge force on the OWT foundation in operational irregular sea states. Furthermore, highly energetic irregular sea states with a 100-year return period saw surge forces reduced by 19%. Although a fixed WEC operating purely as a wave mitigation device was beneficial, utilising a heave and surge coupled WEC proved to be a far more effective method for load reduction.