Semi-analytical study on the hydrodynamic performance of an interconnected floating breakwater-WEC system in presence of the seawall

•A semi-analytical model for the dual pontoon system with the presence of the partial reflected seawall was developed.•Hydrodynamic performance of the interconnected floating breakwater-WEC system was analyzed theoretically.•The effect of the seawall on the performance of the system was revealed. Based on linear potential flow theory, a semi-analytical model is developed using the matching eigenfunction method for a dual pontoon system in the presence of partially reflective seawall. To study the motion characteristics of an interconnected floating breakwater-wave energy converter system, the equations of motion in the frequency-domain are studied using the Lagrange-multiplier method. The model is verified using wave flux conservation law. A thorough investigation of the hydrodynamic performance of the integrated system is conducted, and the optimal power take-off damping of the system is derived theoretically. The results show that the proposed system exhibits a qualified wave power extraction performance and wave attenuation performance, and the presence of the seawall affects the performance of the integrated system significantly.