On the Link Between Weather Regimes and Energy Shortfall During Winter for 28 European Countries

Increasing the proportion of energy generation from renewables is a necessary step towards reducing greenhouse gas emissions. However, renewable energy sources such as wind and solar are highly weather sensitive, leading to a challenge when balancing energy demand and renewable energy production. Identifying periods of high shortfall, here defined as when electricity demand substantially exceeds renewable production, and understanding how these periods are affected by weather is therefore critical. We use a previously constructed energy dataset derived from reanalysis data for a fixed electricity system to analyse the link between weather regimes and periods of high shortfall during the winter for 28 European countries. Building on previous work and following similar studies, we provide both a subcontinental and country-specific perspective. For each country, we identify days with critical energy conditions, specifically high-energy demand, low wind and solar generation, and high-energy shortfall. We show that high shortfall is more driven by demand than by production in countries with colder climates or less installed wind capacity, and is more driven by production than by demand in countries with warmer climates or more installed wind capacity. Of the six weather regimes considered here, only a subset is found to favour the occurrence of high shortfall days. This subset affects much of Europe, causing simultaneous shortfall days across multiple countries. Furthermore, if multiple countries experience shortfall days, neighbouring countries are more likely to experience shortfall days. Motivated by this result, we examine the hypothetical impact the coldest European winter of the 20th century, 1962/1963, would have had on the present-day energy system. We found that persistent blocking conditions associated with that winter, if they occurred today, would lead to higher demand and shortfall across Europe during most of the winter and would be extreme in this respect compared to other winters.