Abstract

Ocean waves are considered a potentially untapped renewable resource that is 800 times denser than wind energy. With a vast coastline of nearly 32,000 km, China offers a huge potential for harnessing wave energy. This paper utilizes the boundary element method to compare the energy absorption characteristics of two wave energy converters (WECs) with conical and hemispherical buoy shapes (with the same displacement, equal 905203 kg) as point absorber devices in the Chengshantou area of the Shandong Peninsula, which occurs mainly in low and moderate sea states, where a linear response is appropriate. Only heaving motion and regular waves are considered in the hydrodynamic response analysis. Hydrodynamic coefficients such as the Froude-Krylov force, radiation damping, additional mass, diffraction force, excitation force and response amplitude operators (RAO) are compared to determine the most appropriate shape. The maximum efficiency of a power take-off (PTO) device was simulated and the velocity response of the buoy was observed. Monthly variations in average absorbed power and efficiency were calculated for both shapes of the buoy. The results indicate that the hemispherical buoy is more efficient than the conical buoy, due to its better hydrodynamic characteristics and smoother interaction with incident waves.