On renewable energy community implementation in historic cities: A city-scale validated model

• Suburban PV systems can significantly support historic city energy needs. • Mixed-use RECs balance self-sufficiency and energy export to the grid. • Optimized RECs reduce grid load while increasing renewable energy sharing. • Scalable REC models enable renewable energy adoption in constrained historic areas. Renewable Energy Communities (RECs) have emerged as a key strategy for transforming global energy management, promoting renewable energy generation and sharing, particularly through building-integrated photovoltaic (PV) systems. This innovative study focuses on designing a REC that facilitates renewable energy sharing between suburbs and historic city centers, where renewables installation is often constrained. Using city-scale energy simulations for the city of Perugia, Italy, the study evaluates electricity demand and potential PV production in two zones – northern and southern – each served by a unique primary energy station. Results revealed that multi-family houses in historic areas were the main contributors to overall electricity demand, while large offices had the highest average monthly consumption, particularly in summer. In the PV production analysis, increasing roof coverage to 70% significantly increased energy generation, with single-family houses in the northern zone producing up to 4 kWh more, daily, compared to 30% coverage. Mixed-use REC configurations (residential and commercial) achieved an optimal balance between self-sufficiency and energy exported to the grid, with average monthly shared energy reaching 32.4 kWh and 61.5 kWh in northern and southern areas, respectively. This study significantly contributes to demonstrating the feasibility of using suburbs-generated renewable energy to support energy innovation of historic city centers where restrictions on renewables installation are common. Findings underscore the potential for scalable, replicable REC models across other historic cities with similar constraints, but different climates and regulations. Such insights offer a pioneering model that bridges the gap between energy efficiency and heritage conservation in urban planning.