Influence of mooring configurations on the hydroelastic responses of a floating photovoltaic array

Floating photovoltaic (FPV) systems have gained increasing attention for offshore renewable energy generation. However, the deployment of these systems in open seas is associated with significant challenges due to wave-induced deformations and structural failures analysis accounts for the fluid–structure interaction and is essential for evaluating FPV systems. This study assesses the influence of mooring configurations on the hydroelastic responses of a prototype offshore FPV array, which consists of six interconnected floats. The three mooring configurations include tendon leg buoys with shared mooring, tendon leg buoys with shared mooring and clump weights, and catenary-shape anchor lines. The numerical study is carried out using a previously developed hybrid finite element and boundary element method. The floats are modeled as rectangular solid plates using Mindlin plate theory, and the modal expansion method is adopted to reduce computational time of the FPV array with 2724 degrees of freedom. We apply Irvine’s equations to analytically model the mooring lines connected to the fairleads, and then linearize the mooring stiffness. The modified stiffness matrices including hydrostatic stiffness, connection stiffness, and mooring stiffness are used in the hydroelastic analysis. A detailed sensitivity study is performed for the FPV array considering various mooring properties and wave periods. Among the three evaluated mooring configurations, the clump weight proved to be the most balanced solution. It offers a moderate increase in vertical mooring stiffness while keeping pretension loads relatively low, namely less than 150 kN and maintaining hydroelastic bending moments and plate deformations across the FPV array at modest levels, with the percentage difference in hydroelastic response remaining under 5%. This can be ascribed as a practical and cost-effective option for improving the structural integrity and motion performance of offshore FPVs.