Modelling wind resources in climate change scenarios in complex terrains

Wind farms have suffered a spectacular growth in Europe in the last few decades. However, future changes in climate could affect the availability of the wind resource in certain regions. This work assesses the capabilities of a Regional Climate Model (WRF) applied at medium-to-high resolution (10 km, 33 vertical layers) over a particularly complex and vulnerable terrain (North Eastern Iberian Peninsula) to derive mean wind speed and direction for 1981-2000. The model is able to reproduce geographical wind patterns, although it generally overemphasises surface wind intensity when compared to individual observations. Projections of mean wind speed changes for 2031-2050 suggest a decrease in surface wind intensity. Energy density estimations at 60 m agl (typical hub-height) show that the implications of the wind speed weakening could affect the preferential areas for the wind farm locations defined at present. Reductions up to 20% of wind energy density are found already in mid-21st century. Therefore, it is advisable to derive dynamic methodologies to assess the preferential areas for wind farm locations, not only considering past-time wind climatologies, but also considering future climate changes in geographical patterns. Regional Climate Models applied at medium-to-high resolution can be useful for this purpose.