Power performance and dynamic characteristics of a 15 MW floating wind turbine with wave energy converter combined concept

• A combined wind-wave energy generation concept based on a 15 MW class wind turbine is presented. • A fully coupled numerical framework of the combined concept is established. • By rough estimate, wave energy converters account for 11.4 % of the annual power production of the combined concept. • The response of the combined concept is more stable and it has comparable power to the pure 15 MW turbine in wind power output. Recently, the large-scale development of Floating Offshore Wind Turbines (FOWTs) has raised attention to efficient energy capture and conversion. Combining a wave energy generator with a wind turbine system enhances the overall power production and reduces operating costs, effectively lowering the Levelized Cost of Electricity (LCoE). This work proposes a novel combined wind-wave energy generation concept consisting of a 15 MW class semi-submersible FOWT and four heaving-type torus-shape Wave Energy Converters (WECs) integrated with the platform columns. A fully coupled numerical model of aero-hydro-elastic-servo-mooring is developed based on the SIMO-RIFLEX framework. The power performance and dynamic response of the combined concept are statistically and analytically investigated by time-domain simulation for several sets of working load cases. The results show that introducing tori will bring additional restoring moments and damping effects to the platform, contributing to stable motion. In the rated operating condition, the pitch amplitude of the combined concept is 31.5 % less than that of the FOWT. At the same time, the torus-shaped WECs hardly affect the power performance of the wind turbine. The combined concept provides an additional contribution of wave energy, which is about 11.4 % of the annual power production in the rated operating case. Regarding dynamic characteristics, the combined concept exhibits a greater sensitivity to wave excitation.