Dynamic simulation of a multi-stage solar-driven combined PV-membrane distiller

Water scarcity and increasing energy demands represent critical global challenges, underscoring the urgent need for sustainable freshwater production technologies. Compact multi-stage photovoltaic-membrane distillation (PV-MD) systems have emerged as a promising solution, offering high freshwater productivity and electricity generation through efficient solar energy utilization. However, existing research has mainly focused on steady-state analyses, while the year-round performance of compact PV-MD systems under realistic, time-varying environmental conditions across different regions remains insufficiently understood. In this study, the transient water and electricity generation performance of a compact multi-stage PV-MD system is evaluated under actual environmental conditions across nine European regions. The dynamic and quasi-steady-state models are compared to assess the influence of transient thermal effects on performance prediction. The results show that the significance of dynamic effects depends on local climatic conditions, with the daily deviation between the two models reaching 11.2% under representative high-irradiance conditions. More importantly, the annual performance of the device exhibits a strong geographical dependence. In Limassol, with a high annual average solar irradiance of 238 W∙m -2 , the annual freshwater collection reaches 2587 kg∙m -2 and the electricity generation reaches 240 kWh∙m -2 . In contrast, in London, where the annual average solar irradiance is 117 W∙m -2 , the annual freshwater collection decreases to 657 kg∙m -2 and the electricity generation to 133 kWh∙m -2 . These results provide a clearer picture of the climatic dependence and year-round operating characteristics of compact PV-MD systems under realistic conditions. Key takeaway: transient thermal effects are climate-dependent, and annual PV–MD performance shows strong geographical variability across Europe.