The present study aims at assessing the impact of energy absorption by large number of devices (wave farms) on the near shore wave climate using the SWAN spectral wave model. This study is performed for the Portuguese Pilot Zone. In January 2008, the Portuguese Government launched the legislation for a Pilot Zone to support the deployment of offshore wave energy prototypes up to an installed capacity of 250 MW. This zone, with an area of 320 km2, is located 5 to 20km off the northwest Portuguese coast between the 30 m and 90 m bathymetric lines. As a case study, wave farms with Pelamis technology were considered, using the public available information of the wave energy absorption for a range of sea states.
Several configurations for disposal of the wave farms in the pilot zone were assumed. The effect on the shoreline wave climate was assessed in terms of the changes on the significant wave height, mean wave period, and wave direction due to a large scale installation in the pilot zone (202.5 MW installed power). Final objective is to analyse and evaluate its possible effect on the surfing conditions in the nearby beaches or on coastal sediment transportation. As no physical calibration of the model is undertaken, this study is considered a preliminary assessment of the eventual impacts on inshore surfing beaches, however allowing for relevant qualitative conclusions.
