Wave Energy Assessments in the Coastal Environment of Portugal Continental

Abstract

The potential for wave energy extraction can be obtained from the analysis of the wave climate which can be determined with numerical models. The wave energy devices can be deployed in offshore, nearshore and shoreline. From this reason, it is important to be able to assess properly the spatial distribution of the wave energy in various locations from the offshore to the coastline in a specific area. The methodology proposed here considers a SWAN based wave model system focusing in the Portuguese continental coastal environment from deep water towards the nearshore. An analysis of the average and high energetic conditions was first performed for a ten-year period, between 1994 and 2003, considering the most relevant in situ measurements available in the Portuguese nearshore. In this way both the average and high energetic conditions corresponding to the Portuguese continental costal environment have been properly defined. For the most relevant average wave conditions, SWAN simulations were performed in some medium resolution areas covering the northern and central parts of Portugal continental, which are traditionally considered richer in wave power resources. The present work allows the identification of some locations in the continental coastal environment of Portugal with greater potential from the point of view of wave power resources. An important observation is related to the fact that the wave power depends on the product between the energy density spectrum and the group velocity of waves. This means that, although the significant wave height is a relevant parameter when assessing the wave power in a specific site, a location having in general higher wave heights is not necessarily also the richest in wave power.