Syncretizing photovoltaic module and air gap membrane distillation for simultaneous electricity and freshwater production: A comprehensive 5E study

Abstract

The integration of photovoltaic-membrane distillation (PV-MD) systems presents dual benefits of photovoltaic thermal regulation and freshwater cogeneration; however, the systematic evaluation of synergistic mechanisms in PV-air gap membrane distillation (PV-AGMD) systems remains insufficiently explored. This study addresses critical research gaps in unified multidimensional assessment frameworks and PV-AGMD parametric interactions. A comprehensive system-scale mathematical model was developed, incorporating 5E (energy, exergy, economic, environmental and engineering) analyses to evaluate system performance. Key operational parameters—solar irradiation, PV module temperature, feed flow velocity, air gap thickness, and membrane pore size—were systematically investigated through engineering design analysis. Through synergistic optimization, the system achieved exceptional performance metrics, including a power density of 139.16 W m⁻², freshwater production rate of 2.44 kg m⁻² h⁻¹, and energy and exergy efficiencies of 57.01 % and 49.39 %, respectively. Long-term operational stability was validated across diverse climatic conditions in Hong Kong, Hangzhou, Tianjin, and Dalian. Economic analysis based on Hong Kong data demonstrated competitive freshwater production costs of 10.54 USD m⁻³ and significant CO₂ emission reductions of 387.75 tons annually per installation. These findings provide valuable insights into PV-AGMD synergies and offer practical implementation strategies for region-specific applications, contributing to the development of climate-adaptive cogeneration systems.