Effect of mooring system stiffness on floating offshore wind turbine loads in a passively self-adjusting floating wind farm

Abstract

Floating offshore wind turbines (FOWTs) offer a way to reduce wake losses in floating wind farms (FWFs) by using less stiff mooring systems (MS) that allow for self-adjusting layouts. These layouts enable turbines to reposition based on wind speed and direction, improving energy production. This study analyzes three self-adjusting FWF layouts with different MS stiffness and compares the resulting FOWT loads to a baseline FWF with a standard MS design. Our results show that reduced MS stiffness increases loads, especially at the tower base, and yaw stiffness must be maintained above a certain threshold. This is especially important in above-rated wind speeds, where increased aerodynamic yaw moments occur. A self-adjusting layout that adheres to yaw stiffness constraints showed a 1.5% increase in annual energy production (AEP) and a 4% reduction in MS costs using dynamic wake models.