This paper describes the study of the impact of energy absorption by wave farms on the nearshore wave climate and, in special, the influence of the incident wave conditions and the number and position of the wave farms, on the nearshore wave characteristics is studied and discussed. The study was applied to the maritime zone at the West coast off Portugal, namely in front of São Pedro de Moel, where it is foreseen the deployment of offshore wave energy prototypes and farms between the 30 m and 90 m bathymetric lines, with an area of 320 Km2. In this study the REFDIF model was adapted in order to model the energy extraction by wave farms. Three different sinusoidal incident wave conditions were considered. Five different wave farm configurations, varying the position of the wave farm, its number and the width of the navigation channels at each wave farm were analysed. The results for each configuration in terms of the change of the wave characteristics (wave height and wave direction) at the nearshore are presented, compared and discussed for three representative wave conditions.@en

This paper describes the Numerical and Physical Modelling components of the main project entitled "Viability study of the artificial surfing reef of S. Pedro do Estoril". These studies aim to establish the main characteristics (dimensions, orientation and location) of the artificial surfing reef for S. Pedro do Estoril and to analyze its hydrodynamic peifonnance for different incident wave conditions. The main conclusions of both studies were that the reef solution permits the improvement of the surf conditions in the area of S. Pedro do Estoril especially for the most frequent wave in the region. However, in both studies some problems related with strong reflection and vortices in the reef's corners where detected and should be improved in the final solution.@en

The influence of a set of wave farms for wave energy extraction on the nearshore wave climate at the pilot zone in Portugal was studied. Two different wave farms configurations (named B and C) and two representative wave conditions (winter and summer) were considered. Energy extraction did not exceed 9.1 and 21.1%, respectively, of the incident energy in the wave farms for January and July. Energy extraction was very similar for the two wave farm configurations. There were no significant differences on the wave heights observed near the coast when considering the two wave farm configurations and the case without wave farms. This is an abstract of a paper presented at the Eighteenth International Offshore and Polar Engineering Conference (Vancouver, Canada 7/6-11/2008).@en