A Review of Solar Photovoltaic–Thermal–Membrane Distillation Technology

Photovoltaic–thermal–membrane distillation (PV/T-MD) systems have emerged as a promising solution to global energy and water scarcity by efficiently utilizing solar energy for the co-production of electricity and freshwater. This review summarizes recent theoretical and experimental advances in PV/T-MD systems. Following the PRISMA-ScR guidelines, a scoping search was conducted in Web of Science through December 2025, and 37 studies that met the eligibility criteria were included. Given the non-clinical, engineering nature of the included studies, a risk-of-bias assessment and meta-analysis were not performed, and the findings were synthesized narratively. Theoretical studies have developed detailed mathematical models to analyze photothermal and photovoltaic conversion processes, as well as heat and mass transfer mechanisms in membrane distillation, providing critical guidance for system optimization. Experimental research, ranging from laboratory-scale to large-scale field applications, has validated the performance, efficiency, and stability of various PV/T-MD configurations. Innovative designs, including multi-effect membrane distillation (MEMD), high- and low-concentration photovoltaic thermal (HCPV/T, LCPV/T) systems, and advanced heat recovery technologies, have significantly improved thermal efficiency, water production, and overall energy utilization. Despite these advancements, challenges remain in improving system efficiency under dynamic environmental conditions, scaling up modular designs, and integrating multifunctional components. This review outlines future directions, including intelligent control systems, novel material development, and standardized techno-economic assessment (TEA) and life cycle assessment (LCA). These assessments are needed to evaluate the scale-up potential and to further validate the commercial prospects and low-carbon benefits of PV/T-MD systems.