Assessment of Transition-Related Energy Security Instability in European Union Countries Using the DESRI Framework

The article addresses the assessment of energy security instability associated with the energy transition process in the EU-27 countries under decarbonisation conditions. It introduces the original Dynamic Energy Security Risk Index (DESRI), interpreted as a synthetic measure of transition-related instability in the field of energy security. The index is structured around five analytical pillars: external dependence and security of supply, the climate and emissions dimension, efficiency and demand-related factors, structural and transformational characteristics of the energy mix, and the economic and social dimension. The empirical analysis covers the EU-27 countries over the period 2013–2023 and is based on 17 indicators obtained from European statistical sources. The dynamic nature of the model is captured through logarithmic rates of change, volatility analysis using a rolling time window, and the multilevel aggregation of instability components at the indicator and pillar levels. The results demonstrate that transition-related instability in the European Union varies considerably across both countries and time. The lowest DESRI values were recorded, among others, in Italy in 2018, Portugal in 2021, Belgium in 2017, and Austria in 2016, indicating relatively stable transition trajectories in those years. By contrast, the highest levels of instability occurred in Estonia in 2017–2018 and Luxembourg in 2022–2023, reflecting rapid and irregular changes in selected dimensions of the energy transition. The analysis also revealed periods of accumulated transition-related instability, particularly in 2017–2019 and 2021–2022, when the irregularity of transition pathways increased simultaneously in numerous countries. These findings show that energy transition-related instability depends not only on the level of transition advancement but also on the pace, volatility, and irregularity of structural changes. Countries with a relatively favourable static energy security or decarbonisation profile may therefore exhibit elevated dynamic instability when the transition proceeds rapidly or unevenly or requires intensive infrastructural, regulatory, and social adjustments. The article’s main contribution is the development of a replicable dynamic assessment framework that complements conventional static approaches to energy security analysis by identifying instability embedded in transition trajectories. DESRI provides an additional comparative perspective for monitoring the energy transition in the European Union. It may also support the identification of countries and policy areas requiring particular attention regarding security of supply, decarbonisation, demand-side efficiency, structural change, and the social acceptability of transition costs.