Renewable energy communities design: A decision support tool for integrated impact assessment. Insights from the first REC in Cagliari, Italy

Renewable Energy Communities (RECs) play a crucial role in advancing the European green transition and achieving key environmental, social, and economic objectives, such as reducing carbon emissions, improving energy efficiency, and ensuring affordable energy access for disadvantaged and low-income populations. However, most research and initiatives tend to address these issues in isolation, thereby overlooking the full potential of RECs. This paper presents an integrated approach led by a multidisciplinary team from the University of Cagliari and the Municipality of Cagliari (Italy), aimed at establishing the first REC in Cagliari, Italy. The project was established in a social housing neighbourhood to comprehensively address complex social, economic, and environmental needs. A participatory design methodology was adopted to actively involve residents, fostering community engagement and raising awareness of the benefits of RECs, thereby promoting long-term community commitment. A key contribution of this work is the introduction of a decision support tool developed to model energy and cash flows, as well as environmental benefits, thereby optimizing energy consumption, financial outcomes, and CO2 reduction. The case study offers an empirical evaluation of both design and implementation phases, assessing the project's feasibility and overall impact. The tool is designed to be highly replicable in other contexts, particularly for addressing energy poverty in public housing neighbourhoods. The findings highlight also underscore its broader policy implications, demonstrating its usefulness for public administrations and stakeholders in guiding investment and planning decisions that prioritize social value over profit.