Linking energy mix diversity, self-sufficiency, and community maturity: pathways toward a resilient European energy transition

The ongoing transformation of the European energy landscape reflects a multidimensional shift toward sustainability, resilience, and decentralization. This study examines the relationship between changes in the energy mix, energy self-sufficiency, and the development of energy communities (ECs) across five EU countries: Italy, Spain, Germany, Poland, and Greece. A hybrid methodology is applied, combining a systematic literature review, statistical analysis of national energy mixes (2015–2024), and an expert-based Delphi foresight study. The findings indicate that regulatory stability, civic participation, and institutional learning are key enablers of EC development, while fragmented regulations, limited local competences, and infrastructure gaps remain major barriers. Comparative analysis shows that ECs in Germany and Italy have reached higher maturity levels, whereas Greece and Spain represent emerging community-based models, and Poland remains in an early experimental phase. The study’s originality lies in integrating technical, institutional, and social dimensions to assess EC maturity in Europe’s energy transition.