Development of a Point Absorber Type Wave Energy Converter Optimised for Sri Lankan Wave Conditions

Wave energy is recognized as a renewable energy resource with a comparatively high energy density relative to other renewable sources; however, its large-scale exploitation remains limited due to technological, economic, and deployment challenges. As a result, only a small number of wave energy converters (WECs) have been successfully implemented worldwide. This study presents the development and field testing of a double-buoy, point absorber type WEC incorporating a dual rack-and-pinion power take-off (PTO) mechanism, designed for deployment in nearshore sea conditions. The hydrodynamic performance of the proposed WEC was analysed using ANSYS AQWA to evaluate heave response, phase variation and hydrostatic forces for different floater geometries, while the structural integrity of the system was assessed using finite element analysis (FEA). Field experiments were conducted at the old harbour premises in Galle, Sri Lanka (6.029230° N, 80.219010° E), where the average significant wave height was approximately 0.3 m, with dominant wave frequencies in the range of 0.1–0.3 Hz. Numerical predictions were compared with gathered experimental measures to validate the model. Experimental results indicated a peak power output of approximately 60 W and an average power output of around 15 W with an estimated overall conversion efficiency of 8.51%under the tested wave conditions. Future work will focus on improving the power-to-weight ratio and eliminating the bottom counterweight, enabling deployment in variable water depths and enhancing the adaptability of the WEC for broader coastal applications.