Influence of high-resolution bathymetry coverage area on the accuracy of ocean models for tidal current energy applications

Ocean models have been extensively used for characterizing tidal stream energy resource. Although with acceptable results, these models present uncertainties arising from numerical assumptions, physical parameters, or lack of data. This paper analyzes the influence of the available bathymetry data for the surroundings of the area of interest on the model accuracy for estimating generated power and starting and ending times of offshore work windows. Two models were evaluated: one with refined bathymetry data in the area of interest and lower resolution (500 m) in the remaining computational domain, and a second one integrating high-resolution data also for the approaches and the channels adjacent to the area of interest. The second model provided significantly lower errors in estimating offshore work windows for Dynamic Positioning vessels (time-averaged starting and ending time errors reduced from 20 to 9 min and from 8 to 5 min respectively) and divers (from 10 to 4 min and from 17 to 10 min for starting and ending times respectively). These results highlight the importance of identifying the optimal area for detailed bathymetric surveying to enhance the accuracy of regional ocean models. • Bathymetry data in tidal site approaches strongly influences model accuracy. • Power generation estimation error is reduced from 22.63% to 2.46%. • Accuracy simulating flows in channel approaches impacts offshore works planning. • Estimation errors for vessel works’ start and end times are cut by 11 and 3 min. • Estimation errors for divers works’ start and end times are cut by 6 and 7 min.