Renewable Energy Communities in Post-Covid Era. Social networks and local innovation for the construction of decarbonisation scenarios in medium-sized cities

This doctoral thesis is embedded within the scientific debate on ecological and energy transition, approached as a systemic and multidimensional challenge that simultaneously encompasses technological, social, institutional, and environmental aspects, with a specific focus on the European context. Specifically, it explores the decarbonisation of the energy system as a complex process that requires a rethinking of governance models and a profound innovation of local organisational forms. In this framework, Renewable Energy Communities (RECs) are interpreted as enabling tools, endowed with transformative potential that extends beyond the technological domain to embrace practices of active energy citizenship, territorial co-design, and institutional innovation. Defined as legal entities with a non-profit purpose, RECs combine production, self-consumption, and collective sharing of energy from renewable sources, within inclusive and participatory frameworks. The research particularly highlights the role of medium-sized cities as enabling contexts for the experimentation of such models, due to their flexible institutional structure, territorial rootedness, and capacity to activate multi-level collaborative networks. The thesis adopts an integrated methodological framework structured in three phases: (i) an analytical-interpretative phase aimed at constructing the theoretical framework, (ii) a synthetical- evaluative phase based on the comparative analysis of 26 European and national case studies, selected for territorial analogy and categorised into three main archetypes (Community prosumerism, Third-Party-sponsored community, Energy cooperative), and (iii) an applied-experimental phase, focused on the construction of “what-if” scenarios applied to the pilot case of Spoleto (Perugia, Italy). The three scenario configurations demonstrate how the quality of governance, the density of relationships, and the heterogeneity of actors involved significantly influence the effectiveness, legitimacy, and sustainability of RECs, confirming the relevance of a relational and territorial approach to the transition.