Cross-typology Positive Energy District pathways in Mediterranean Southern Italy: harmonised district energy modelling and urban-scale life cycle assessment

Reducing carbon emissions is a central EU objective, and Positive Energy Districts (PEDs) are increasingly recognised as a practical pathway for urban decarbonisation. However, robust cross-typology evidence remains limited, particularly when operational performance is assessed alongside the life cycle implications of renovation measures. This study applies a harmonised PED-oriented workflow across two Mediterranean districts in Southern Italy undergoing deep energy renovation: the non-residential University Campus in Palermo and a mixed-use urban district in Bari. The framework combines consistent PED boundaries and indicators, district-scale energy modelling, rooftop photovoltaic (PV) potential assessment, and life cycle assessment of retrofit packages comprising envelope upgrades, heating, ventilation and air conditioning (HVAC) electrification, and rooftop PV deployment. Results highlight clear typology-dependent energy patterns. Both post-retrofit configurations achieve full electrification, completely phase out natural gas, and consequently shift final energy use towards electricity, partly compensated by rooftop PV generation. In Palermo, rooftop PV supplies 50% of annual post-retrofit electricity demand. In Bari, baseline active cooling was almost negligible and heating demand decreases by 75%. However, introducing electric cooling alongside full HVAC electrification further increases electricity demand, and PV covers 45% of annual post-retrofit electricity demand. Climate change impacts decrease by 59% in the Palermo Campus and 57% in the Bari district, while ozone depletion is reduced by 61% and 74%, respectively. In both case studies, photovoltaic systems are the main contributors to production-stage environmental burdens, while heat pumps are particularly relevant for ozone depletion. Overall, the findings support context-sensitive, life cycle-informed PED-oriented district renovation planning.