Experimental investigation of semi-submersible platform combined with point-absorber array

Abstract The deep ocean contains abundant wave energy but the sea condition is complex for people to obtain ocean energy. Therefore, how to develop a floating wave energy converter that adapts to the severe environment of the deep ocean has become a hot research topic recently. In this paper, a point-absorber array is installed on a three-pontoon semi-submersible platform and a model experiment of such a system is conducted under regular and irregular waves. And, a simplified hydraulic power take-off (PTO) system is adopted to convert wave energy into potential energy of load inserts. Results show that such a combination increases pitch and heave, but the surge is suppressed under certain circumstances. The maximum hydraulic efficiency of the point-absorber array is 35.2%, and the max overall efficiency is 11.1%. Additionally, by comparing performance of each floater in the array, the staggered arrangement of floaters is more conducive to energy harvest.