Feasibility Assessment of Twin Wind Turbines on a Single Spar Platform

Meeting the growing global demand for clean energy requires innovative solutions. One of the innovative solutions in recent years is the deployment of Floating Offshore Wind Turbine (FOWT) systems. Even though, FOWTs offer huge potential for deep-sea deployment, the capital cost remains high and achieving stability at sea is challenging. As a solution, a novel concept of twin turbines on a single spar platform, that aims to maximize energy output while minimizing the costs is proposed. This paper discusses the conceptual design, and feasibility assessment of the proposed concept using numerical simulation in OrcaFlex. Twin 15 MW wind turbines are modelled on a triangular beam structure, and connected to the spar platform through a transition piece. A coupled dynamic response including the mooring system is obtained under turbulent winds of 8 m/s and 16 m/s with irregular waves. The coupled response shows that the spar platform performed well at moderate wind speed of 8 m/s, but showed an increase in the yaw motion at higher wind speed of 16 m/s. To overcome this, linear damping is incorporated in the numerical simulation to account for additional hydrodynamic effects, and obtained result shows that the yaw motion stabilized even under higher wind speeds. It is concluded that yaw motion of the spar needs special attention while discussing the stability of the platform. The results of the generator power demonstrate that the concept of twin turbines on a single spar platform is technically feasible, offering potential for increased energy output and reduced costs.