Influence of Energetic Electron Precipitation on Wind Power Generation in European Countries Mediated by the Polar Vortex

Abstract Electricity generated by wind power turbines is highly dependent on wind speed, and, thus, the weather at the surface. During wintertime, the dominant wind system in the stratosphere, the polar vortex, influences the weather patterns at the surface. Recent research has shown that energetic electron precipitation (EEP) from space into the polar atmosphere affects the polar vortex and winter weather, for example, in Europe. However, a possible effect by EEP on wind power related to atmospheric variations has not been explored. Here we study the effect of EEP (indirectly measured with geomagnetic aa index) on surface winds and on wind power generation in Finland, Sweden, the United Kingdom (UK) and Spain using ERA5 reanalysis data for atmospheric variables and wind power generation provided by the national statistical institutions. We first construct estimates of potential wind power generation for each country from 1950 onwards with records of surface level wind speed. We then use these reconstructions to estimate the amount of variability in wind power generation associated to EEP variations. In accordance with earlier studies related to polar vortex we find that the EEP effect on surface winds is significant only when the quasi‐biennial oscillation of equatorial stratospheric zonal winds is in the easterly phase. During these times the aa index variations can explain up to 40% of wind power generation variability in Scandinavia and the UK and about 20% in Spain.