Impacts of Large Scale Wave Energy Converter Arrays on the Regional Wave Climate

Following years of research and prototype testing of wave energy converters at the European Marine Energy Centre (EMEC) in Orkney, and also in the Inner Hebrides in Islay, device developers and utility companies are now actively pursuing the large scale commercial deployment of wave energy converters (WEC).  Where Pentland Firth and Orkney Waters (PFOW) are known as a prime location for the extraction of tidal energy, the Outer Hebrides of Scotland have been identified as an area with one of the highest wave energy resources in Europe with a mean wave energy potential of 43kW/m.  Although it is unlikely for individual WECs to have a significant impact on oceanographic systems, the same cannot be said for arrays of devices in the shelf and near shore region.  The extraction of energy on a scale of multiple tens of megawatt in a regional development results in the reduced dissipation of wave energy in the environment.

The research investigated to what extent large scale arrays of WECs in the coastal zone influence the wave climate with resulting effects on coastal and sub‐littoral processes and their ecological consequences.  Cumulative effects of multiple wave farms in close spatial distribution will be analysed with a particular focus on whether it is possible to offset detrimental impacts caused by climate change through a smart siting strategy of WECs to influence the local wave climate and associated processes.  The research focussed on the Outer Hebrides of Scotland, where currently three WEC developments with a combined installed capacity of 64MW are in the planning stages.  Coastal erosion is of high relevance in the southern parts of the Outer Hebrides and the strategic siting of WECs offers the potential not only to extract renewable energy from the sea, but also to support the local coastal protection programme.