Wave energy resources: Wave climate and exploitation

In identifying the most convenient zones for harvesting wave energy, it is natural to be attracted by the areas where we find the highest mean energy values. The obvious examples are the storm belts. A more careful analysis reveals that for practical use other factors need to be taken into account. Some of the main ones are the energy spread in frequency and direction, and its seasonality, without discussing the cost of the structure basically related to the conditions to be withstood. This reveals that other areas, in particular the equatorial ones, can be conveniently used, and be possibly advantageous from various points of view. Based on the results of the ECMWF ERA-Interim reanalysis and of altimeter data, we have carried out a comparative analysis between two locations with opposite characteristics, in the North Atlantic and in the Equatorial Pacific respectively. The quantified results confirm that less energetic, but more regular and less extreme, areas have a potential comparable to that of the classically considered storm belts.

► We assess the wave energy at two locations with rather opposite wave climates.
► We consider spectral and temporal distributions to derive the actual power potential.
► Results show that the local mean energy is not a sufficient indicator for wave power.
► Areas with uniform input of swell energy appear attractive for energy harvesting.