Numerical Modeling of a Lightweight Point Absorber for Wave-Powered Desalination

This paper presents Water Bros Desalination's (WBD) work in developing a compact wave-driven desalination system for coastal disaster response. To predict system loads and potable water production, accurate simulation of the Wave Energy Converter (WEC) is crucial. The paper outlines the numerical model setup using WEC-Sim, a standard tool for simulating WECs in the MATLAB/SIMULINK environment. By focusing on regular waves, the study models the buoy motion within the heave, surge, and pitch degrees of freedom. A standard WEC-Sim setup was used, yielding a linear model, which required preliminarily calculating the hydrodynamic coefficients in NEMOH Boundary Element Method (BEM) software. The WEC-Sim model of a similar wave-powered desalination system validated the modeling methods. The "Hydraulic and Electric Reverse Osmosis Wave Energy Converter" (HERO WEC), developed by the National Renewable Energy Laboratory (NREL), was selected for this validation. The HERO WEC produces over 6 times more water than the WBD WEC for the same regular wave state. Further, the dynamic behavior of both desalination WECs appears to differ significantly in motion amplitude and frequency.