Rooftop agrivoltaics and rainwater harvesting for climate-resilient buildings: A water-energy-food nexus assessment

Future weather scenarios demand more resilient and resource-efficient buildings. Although retrofit solutions continue to advance, climate change requires interventions that address not only energy efficiency, but also resilience and resource management simultaneously. This paper evaluates the potential of rooftop agrivoltaic systems that integrate urban agriculture, photovoltaic generation, and rainwater collection to enhance building resilience and reinforce water-energy-food (WEF) synergies in urban environments. The strategy was tested through dynamic EnergyPlus simulations in a reference residential building across nine climate zones in Catalonia (Spain). The results show climate-dependent benefits, with the most consistent performance observed in the Csa climate (Barcelona), where the strategy achieved the strongest synergy between climate resilience and resource management. Simulations under current and future climate scenarios show that the strategy maintains robust performance over time, achieving consistent reductions in energy demand, emissions, and total discomfort hours. Resilience is also shown to increase in several scenarios, which supports the strategy’s viability under present and projected conditions. Implementing such a strategy can support cities and buildings to become better prepared for climate variability, informing long-term urban planning and retrofit pathways toward more adaptive, resilient, and sustainable built environments.