Wave Energy Potential in the Mediterranean: Insights from High-Resolution Satellite Altimetry, In-Situ Data and the ERA5 reanalysis

Marine renewable energy plays a pivotal role in advancing the European Green Transition. To unlock its full potential, it is crucial to acquire precise and detailed knowledge of resource distribution along European coasts and overseas islands. This study focuses on evaluating wave power potential using an empirical method to derive wave periods essential for wave power computations. High-resolution sea-state data were obtained from two satellite altimetry missions—Sentinel-3A/B and CryoSat-2— reprocessed with the advanced SAMOSA+ retracker, supplemented by in-situ measurements from wave buoy networks in Spain, France, Italy, and Greece. We integrated altimeter-derived significant wave height and backscatter coefficients with buoy-measured wave periods through a collocation technique. The 20 Hz data resolution from CryoSat-2 and Sentinel-3 altimeters, corresponding to an along-track resolution of approximately 300 meters, represents a significant improvement over existing altimeter dataset. This enhanced resolution enables more precise wave power density estimations in coastal zones, where wave energy converters are typically deployed. Given the scarcity of wave buoy data along the North African coast, we validated our results by applying the Gommenginger et al. (2003) method to all available buoy data distributed across the northern Mediterranean. Additionally, to achieve a more uniform distribution of wave buoys across the basin ERA5 grid points were used as virtual buoys. Wave period and wave power estimates derived from altimeter data were then compared with those from ERA5 reanalysis data A thorough statistical analysis of the results identifies the most suitable approach, providing a robust framework for the wave energy resource assessment and supporting the development of sustainable energy infrastructure in coastal regions. This study, conducted as part of ESA's ongoing WAPOSAL project investigates the wave energy potential in the Mediterranean Sea, a region of strategic importance for renewable energy exploration.