Wave energy conversion energizing offshore aquaculture: Prospects along the Portuguese coastline

Abstract

This paper seeks to identify promising sites and technologies, in Portugal, for co-located wave energy conversion and offshore aquaculture, whilst providing benchmark implementation references and guidelines to researchers. Accordingly, two case study sites are considered for deployment of five wave energy devices and up to six aquaculture species. A thorough analysis in terms of power ratios, efficiency, redundancy, species viability, device survivability and costs is performed, seeking to find viable co-located solutions. It is found that the Wave Dragon device yields the most promising energy demand coverage and energy output (5 226 to 6 817 MWh/year). Nevertheless, it may require rescaling towards optimal operation, while the OCECO 4 excels in terms of capacity factor (0.24–0.29) and default adaptation to the deployment sites. The WaveRoller® has the lowest single-unit cost (125 €/MWh) but requires up to nine units to cover all the energy demand targets. Larger wave farms are required for the BBDB and AquaBuOY, albeit with potentially greater economies of scale and single-unit redundancy. These sites also enable cultivation of most of the considered species, even under ideal conditions. Lastly, it is recommended that the devices enter survivability mode at a significant wave height threshold of 5.5 m.