Evaluating the gravity wave energy potential off the Brazilian coast

Abstract

The wave energy potential on the Brazilian coast is estimated using in-situ buoy data and model data. The results present a greater potential on the southern-southeastern coast than on the northeastern coast, but the variance is also larger. These seem to be associated with the different atmospheric regimes. While in the northeastern portion the trade winds determine the wave regime, in the south the passage of cold front systems plays a major role. For almost all regions and throughout the year, the energy potential oscillates between 10 and 30 kW/m, the most efficient range to implement wave energy converters. The occurrence of sea states is also assessed, showing that the passage of cold front systems also creates different sea states in the S-SW area. Finally, the most common sea states and energy flux are estimated, showing a shift towards longer periods and higher waves for the latter. On the S-SW coast, although the most frequent sea states have waves with periods around 8 s, the energy flux has a more balanced distribution between these and the waves with periods around 11s, the common period for waves generated by cold front systems. This result shows that the most common sea state is not necessarily the one that should be considered when planning wave energy converters for the region.