Ocean power technology design optimization

•The National Renewable Energy Laboratory and Ocean Power Technologies conducted a collaborative code validation and design optimization study for OPT’s PowerBuoy® wave energy converter.•Viscous drag coefficients for the PowerBuoy floats were evaluated using computational fluid dynamics.•WEC-Sim PowerBuoy models were validated with experimental power output and fatigue load data provided by OPT.•WEC-Sim models were used to simulate and compare the power performance and loads for operational conditions, extreme conditions and directional waves, for each of the PowerBuoy design variations.•Ratios of power to weight, loads, and areas were used as a final comparison of the potential PowerBuoy WEC designs.