In-Ocean Validation of a Deterministic Sea Wave Prediction (DSWP) System leveraging X-Band Radar to Enable Optimal Control in Wave Energy Conversion Systems

Advanced controls optimization offers a promising pathway to improve performance, reduce structural loads and thereby reduce the Levelized Cost of Electricity (LCOE) for wave energy conversion (WEC) systems. Model predictive control (MPC), which remains the preferred algorithm framework for WEC devices requires a wave excitation force forecast on the order of 30 seconds into the future to be effective. To establish the feasibility of forecasting the wave resource within this time-horizon, we benchmarked a wave prediction system that leverages an X-band ship navigation radar using a set of field campaigns carried out offshore Santa Cruz in California. For quantitative assessment of the prediction accuracy, we evaluated error metrics based on correlation and normalized mean absolute error between measurement and prediction. The relationship between prediction accuracy and key environmental factors prevalent during data collection (wave height and wind-speed) was analyzed through a set of sensitivity studies. Overall, the results show that wave prediction accuracy is good enough to enable MPC based control, which establishes a credible technology pathway to utilize these control techniques on commercial devices at sea.