Inter-annual variability of wind indices across Europe

There is considerable interest in the potential impact of climate change on the feasibility and predictability of renewable energy sources, including wind energy. However, relatively little research has been conducted to assess the historical variability of wind energy density across different spatial scales or the degree to which one can derive robust projections of future wind energy density. This article presents analyses of the historical variability of annual wind indices across Europe to provide a context for possible future scenarios, as well as possible tools for use in developing prognoses that are suitable for application to output from global climate models. There is a high degree of covariance and inter-annual variability of wind indices in northern European countries. Reanalysis data sets suggest that the axis about which the correlations of latitudinally integrated wind indices over Europe change sign is approximately 45 degrees N and that there is evidence of compensating trends in wind energy indices north and south of this latitude. Climate projections from HodCM3 do not indicate evidence for changes in the spatial and temporal variability of annual wind indices, but these results are rather uncertain owing to biases in the variability of wind indices derived from HadCM3 output. Copyright (c) 2005 John Wiley & Sons, Ltd.