This study addresses the growing role of Renewable Energy Communities (RECs) in supporting decentralized renewable energy integration and improving local energy self-sufficiency within the European energy transition framework. The work aimed to evaluate the technical and economic feasibility of a municipal REC in Pattada, a small municipality located in Sardinia, Italy, through an energy balance analysis based on distributed photovoltaic generation and shared electricity consumption. A techno-economic assessment framework was developed by combining the estimated electricity production of municipally owned photovoltaic systems with the load profiles of municipal, commercial, and residential users participating in the REC. The photovoltaic energy production was estimated using the Photovoltaic Geographical Information System (PVGIS) simulation platform, while the shared energy within the REC was evaluated by considering the simultaneity between electricity generation and demand under different residential participation scenarios. The results showed that the municipal photovoltaic systems achieved an annual electricity production of approximately 506.41 MWh, while direct physical self-consumption remained limited to 3.10 MWh/year due to the mismatch between municipal demand and photovoltaic generation profiles. The analysis further showed that the REC reached an energy equilibrium condition with the participation of 285 residential users, corresponding to nearly 23% of the households within the municipality, allowing virtually shared energy to reach 425.92 MWh/year. The economic evaluation demonstrated that the municipal administration obtained the highest share of the overall economic return, mainly driven by electricity exported to the grid and incentive revenues associated with shared energy. The results indicate that the integration of municipally owned photovoltaic systems within REC configurations provides an effective approach for improving local energy sharing and enhancing the economic viability of distributed renewable energy systems in small municipalities. The proposed framework offers practical support for local administrations in planning renewable energy investments and optimizing REC configurations under real operating conditions.

Renewable Energy Communities (RECs) are increasingly recognized as decentralized energy systems capable of improving renewable energy integration, enhancing local self-consumption, and supporting the transition toward low-carbon energy infrastructures. However, the effective deployment of RECs still faces significant challenges related to the integration of spatial analysis, energy modelling, operational optimization, and socio-economic assessment within a unified framework. This study investigates an integrated multi-objective framework for the design, evaluation, and operational support of RECs through the combination of geospatial analysis, energy performance modelling, and digital decision-support tools developed within the ENEA Smart Energy Communities (SEC) platform. The proposed methodology was developed by integrating spatially explicit territorial datasets, renewable resource assessments, electricity demand profiles, and multidimensional key performance indicators (KPIs) within a coordinated analytical framework. Three complementary tools were implemented and evaluated: the geoCER geoportal for territorial-scale renewable energy planning and REC scenario modelling, the DHOMUS platform for residential load monitoring and self-consumption optimization, and the Local Token Economy (LTE) system for token-based user engagement and energy-aware behavioral incentives. The results showed that the integrated framework effectively supported the assessment of REC configurations under different territorial and operational conditions. In the Anguillara Sabazia case study, the REC configuration increased the Self-Consumption Index (SCI) from 30% to 65% and the Self-Sufficiency Index from 36% to 79%, while reducing the Energy Surplus Index from 70% to 35%. In the Sardinia case study, the scenario-based analysis demonstrated that renewable energy integration and coordinated energy sharing significantly improved territorial self-sufficiency under optimized REC configurations. The geospatial modelling approach also enabled the identification of suitable renewable deployment scenarios while considering environmental and territorial constraints. The results indicate that the integration of energy modelling, digital monitoring systems, and spatially explicit planning tools provides an effective pathway for improving the operational performance, flexibility, and scalability of RECs. The proposed framework offers practical support for decentralized energy planning, distributed renewable energy management, and data-driven decision-making processes in future community-based energy systems.

Photovoltaic (PV) panels experience significant efficiency degradation under elevated operating temperatures, making effective thermal regulation an important challenge for sustainable solar energy systems. Passive cooling techniques based on phase change materials (PCMs) have attracted considerable attention because of their latent heat storage capability; however, the low thermal conductivity of conventional paraffin-based PCMs restricts heat transfer performance during transient melting processes. This study investigates the thermal behavior of a PV cooling system employing paraffin enhanced with Ag–Al$_2$O$_3$–TiO$_2$ ternary nanoparticles and porous metal foam. A transient numerical model was developed using a Galerkin finite element approach combined with an adaptive mesh refinement technique to accurately capture the movement of the melting front and the associated thermal gradients. The thermal performance of the proposed cooling configuration was evaluated through temperature distribution, liquid fraction evolution, and PV electrical efficiency under transient operating conditions. The results showed that the incorporation of ternary nanoparticles and porous metal foam significantly enhanced heat diffusion and accelerated the melting process within the PCM domain. The liquid fraction increased by approximately 38.66% compared with the conventional PCM configuration, indicating more effective latent heat absorption and faster phase transition behavior. It was also found that the enhanced cooling system reduced the PV panel temperature by nearly 12.75% and improved the PV electrical efficiency by approximately 26.75% relative to the uncooled case. In addition, the incorporation of pure paraffin beneath the PV panel reduced the panel temperature by about 9.94%, confirming the effectiveness of latent heat storage for passive thermal regulation. The results indicate that the simultaneous utilization of ternary nano-enhanced PCM and porous metal foam provides an effective passive cooling strategy for PV thermal management. The proposed configuration offers improved thermal energy dissipation, enhanced phase change heat transfer characteristics, and promising potential for the development of high-performance solar energy systems.