Assessing the Spatiotemporal Variability and Complementarity of Renewable Energy Resources across Europe

Europe's energy transition towards renewable sources is imperative for achieving sustainability and mitigating climate change. However, the intermittency of solar and wind power necessitates a detailed evaluation of their combined potential. This study analyzes the spatiotemporal distribution and variability of solar and wind power resources across Europe from 1979-2022, using ERA5 reanalysis data. Empirical Orthogonal Function (EOF) analysis is used to characterize the spatiotemporal patterns of variability in irradiance and wind speed up to multidecadal timescales. Also, the variance of the estimates of the capacity factor (CF, i.e., electricity generation normalized to the installed capacity) is compared with EOF patterns. Results show that the leading three modes of EOF represent the most variance in spatial distribution of irradiance and wind speed over Europe, with significant interannual and interdecadal fluctuations influencing spatiotemporal distribution. The temporal variance for offshore and onshore wind exhibits larger spatial heterogeneity. The spatial heterogeneity of the variance of solar CF is lower than that of wind power CF, but its amplitude is much higher in most regions. There is a negative linear correlation between the variance and mean of CF for both solar and wind power. Southern Europe shows the lowest intermittency in solar power, while eastern and northern Europe exhibit a lower intermittency of onshore wind. Offshore wind potential is high over the Norwegian and Mediterranean Seas. We also identify areas of maximum complementary between solar and wind power resources, attempting to use large-scale datasets and established knowledge of patterns of climate variability to fulfill local-scale renewable energy requirements best. Future research will focus on developing advanced hybrid models to integrate diverse renewable energy sources, exploring their synergistic potentials.