Resilience of polygeneration systems for residential buildings in Spain

• Polygeneration system design for resilience, economic, and environmental benefits. • Sunny zones achieve higher benefits than North-Atlantic zones. • Best results appear when outages coincide with peak solar hours. • Almost no economic difference between facing short and long outages. • EU 2030 targets and outages resilience raise polygeneration feasibility challenges. This study evaluates polygeneration systems as a strategy to enhance the resilience, economic performance of residential building energy systems across different Spanish climate zones, with the purpose of identifying the most appropriate approximation and the capacity of complying with future environmental regulations. A Mixed-Integer Linear Programming (MILP) model is developed to optimize system design and operation under blackout scenarios ranging from 1 to 24 hours, particularly during peak electricity demand, comparing the results with those from conventional energy systems. The results show that polygeneration systems deliver the highest economic savings and resilience when outages coincide with peak solar production, achieving up to 36% operational savings and approximately 30% CO 2 reductions in Mediterranean and Continental climate zones. In contrast, North-Atlantic climate zones show limited benefits due to lower solar resources. Moreover, when both resilience and compliance with EU 2030 environmental targets are enforced, feasible solutions are foreseen for the first two climate zones, while the North-Atlantic would require too high investments. Environmental benefits are contingent upon PV penetration, while cogeneration modules are crucial in areas with low solar resources. Overall, polygeneration systems are a promising approach for resilient and sustainable residential energy supply with adequate renewable resources.