Assessing energy security and sustainable development goal 7 performance in EU - A meta four-parallel two-stage undesirable dynamic DDF model

Amid escalating geopolitical uncertainty and accelerating low-carbon transition pressures, energy security has become a critical issue affecting sustainable development and the achievement of SDG7. This research integrates APERC's four dimensions of energy security with Parallel DEA, Dynamic Network DEA, and meta-frontier analysis to develop a meta four-parallel two-stage undesirable dynamic directional distance function (DDF) model. The proposed framework helps evaluate the efficiency performances of energy security and energy sustainability in 26 EU countries during 2018-2022 under geopolitical shocks and energy transition pressures. The empirical results reveal significant technological heterogeneity between Eastern and Western European countries. Eastern European countries exhibit comparatively smaller technology gaps relative to the meta-frontier. Accessibility and acceptability are the major sources of inefficiency in many EU countries. Malmquist productivity decomposition indicates a clear temporal shift in the sources of productivity change. While efficiency improvement and technological progress mainly drove productivity improvement in 2020, technological regress gradually became the dominant source of productivity deterioration after 2021. This pattern may reflect the challenges that geopolitical shocks and energy transition pressures pose for the technological frontier of EU energy systems. The primary contribution of this study lies in integrating meta-frontier analysis, parallel structure decomposition, dynamic network linkages, and undesirable DDF measurement into a unified analytical framework that simultaneously captures technological heterogeneity, multi-stage structures, and intertemporal dynamic relationships. The findings provide important policy implications for improving EU energy resilience and renewable energy governance under geopolitical uncertainty.