The Impact of the NAO on the Solar and Wind Energy Resources in the Mediterranean Area

The influence of the NAO on the solar and wind energy resources in the Mediterranean area, in particular, and over the whole North Atlantic area, in general, has been explored based on the analysis of 20 years of reanalysis and satellite data. The analysis was carried out for the winter and annual periods and proved the existence of a marked influence of the NAO pattern on the spatial and temporal variability of the solar and wind energy resources in the study area. Particularly, the NAO signature on the solar/wind energy resources was found to be a north-south dipolar pattern, with the positive/negative centre over the Mediterranean area. Although the spatial patterns obtained are similar, the nature of the relationship obtained for wind energy was found to be less linear and more complex than that attained for solar energy. A composite analysis revealed that interannual variability of the solar and wind energy resources in the Mediterranean area can reach values above 20% in winter and 10% in the annual case associated with changes in the NAO phase. Finally, the analysis of the spatial patterns of the NAO influence on the solar and wind energy resources revealed the existence of spatial and local balancing between these two energy resources in the study area. Results are of interest regarding the estimation of the expected interannual variability of the wind farms and solar plants production in the study region.