Climate variability on Fit for 55 European power systems

In the last twenty years, the European continent has seen a remarkable increase in renew- able energy generation. The total capacity of renewable electricity generation in Europe went from 221 GW (with 13 GW of solar/wind) in 2000 to 725 GW (with 427 GW of wind/solar) in 2021 (+230%) [2]. With most renewable production being difficult to predict by nature, deal- ing with the variability of renewable energy sources (RES) is still one of the biggest challenges for efficiently integrating low-carbon sources in power systems [3]. Since RES operations are tightly linked to weather (due to the availability of wind, sunshine or precipitation), under- standing the impact of meteorological and climatic variables on electricity systems is becoming increasingly important for multiple stakeholders along the value chain, from utilities providing (ancillary) services to policy makers ensuring security of supply [4]. In general, introducing inter-annual variability into power system models can lead to more robust estimations of the storage capacity needed in systems with a high penetration of renewables [5]. Furthermore, assessing and quantifying the variability of electricity generation and related makes it possible to improve the design of low-carbon energy systems and increase the penetration of RES with power system reliability in mind. There exists a growing stream of literature assessing the impact of climate variability and change on electricity systems and markets [4, 6]. Most articles, however, reflect on the impact

of a specific climatic variable on one specific electricity system parameter. For example, previ- ous studies analysing the impact of RES variability on European electricity systems have mostly focused specifically on wind and solar resources [7–10] or power system planning [5, 11–13]. Moreover, the majority do so by focusing on a specific country or region in an isolated man- ner, for example by analysing the sensitivity of the power sector to climate change (for example for different global locations [14–16]. Our paper aims to provide a more comprehensive assess- ment by analysing in an integrated future European energy context the impact of climate vari- ability on power system operations and indicators, including generation from renewable energy sources (solar, wind and hydropower), demand, carbon dioxide intensity and cross- border flows. The work addresses two different aspects: 1) co-variability among European countries and 2) analysis of the predominant weather-based patterns. The co-variability of power production from renewable sources in different areas has usually been studied with a focus on the comple- mentarity between wind and solar [17–21]. Similar assessments extended to power systems operations are, however, not common [22]. Regarding weather patterns, we link the operations of European power systems to a set of specific large-scale weather conditions, using the pat- terns identified in [23] and applied in successive works [24–27]. While recent work has investi- gated the impact of weather patterns at a large scale [28–30], our analysis provides insights

into the impacts of frequent patterns in a future European energy context. By associating the identified weather patterns with a configuration of the European power system, in terms of renewable energy generation, cross-border exchanges and other parameters, the analysis allows us to investigate the relationship between large-scale weather regimes and daily power system operations in a 2030 European energy context. As such, the work enables policy-mak- ers to assess with efficiency the impact of climate variability in decarbonising electricity systems. Below, we elaborate on the data and models used to perform our modelling analysis. Next, we discuss the impact of natural variability of meteorological parameters from three different perspectives: 1) measuring power system variability; 2) measuring the co-variability between regions and; 3) identifying patterns in the impact of weather regimes. We conclude by discuss- ing the implications of our work for power system planners and policy makers. PLOS ONE Climate variability on Fit for 55 European power systems PLOS ONE | https://doi.org/10.1371/journal.pone.0289705 December 20, 2023 2 / 16 Funding: The author(s) received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist.