Stability Analysis and Environmental Influence Evaluation on a Hybrid Mooring System for a Floating Offshore Wind Turbine

Abstract

Floating offshore wind turbines (FOWTs) are one of the innovative solutions to achieve net-zero emissions. Given that Taiwan has abundant wind power resources in its western waters and wind farms are evaluated as potential sites, a strategic emphasis on the extensive expansion of wind power is imperative. This paper chooses four different designs of hybrid mooring systems, comparing them with the conventional pure chain mooring arrangement in shallow water regions in Taiwan through integrated numerical simulations, ANSYS AQWA, and Orcina OrcaFlex. The use of synthetic fiber ropes in hybrid moorings provides substantial economic and operational advantages, making them the preferred alternative to traditional chains in deepwater offshore renewable energy (ORE) mooring configurations. Hybrid mooring enables the FOWT to survive in extreme sea conditions and is presented as the ultimate limit state (ULS) and fatigue limit state (FLS). In addition, hybrid mooring not only reduces mooring line costs but also minimizes the footprint area on the seabed, enhancing economic competitiveness and optimizing marine space utilization. However, it increases the entanglement risk that may pose a potential threat to marine mammals. Building on prior research, this paper proposes a unique approach to calculate the mooring line swept volume, which is essential for entanglement assessment and marine spatial planning.