Abstract
Solar-driven seawater desalination represents a critical pathway for addressing freshwater scarcity and advancing low-carbon water–energy systems, yet its transition from laboratory-scale innovation to engineering deployment remains constrained by incomplete understanding of multiscale energy conversion mechanisms and insufficient system-level integration strategies. Existing reviews have predominantly focused on specific desalination technologies or localized performance enhancement approaches, lacking a unified framework that connects fundamental energy transformation, technological evolution, and engineering implementation. This review develops a multiscale analytical framework centered on solar energy conversion, heat and mass transport, and integrated energy–water management to systematically elucidate the scientific principles and development pathways of solar-driven seawater desalination. The fundamental mechanisms governing solar absorption, photothermal conversion, interfacial evaporation, phase-change heat transfer, and exergy utilization are first analyzed, followed by a comparative evaluation of representative technologies, including multi-effect distillation, multi-stage flash desalination, membrane distillation, and interfacial solar evaporation, in terms of energy utilization characteristics and operational applicability. Furthermore, key strategies for improving system performance are critically reviewed, encompassing photothermal material engineering, evaporation interface regulation, multistage thermal cascade utilization, thermal management optimization, and salt crystallization control. Beyond component-level enhancement, this review highlights the transition toward multi-energy integrated architectures involving photovoltaic systems, thermal energy storage, industrial waste heat recovery, and regional integrated energy systems. The major scientific and engineering challenges limiting large-scale application are systematically identified, including irreversible energy losses, coupled heat and mass transfer limitations, solar intermittency, degradation induced by fouling and salt crystallization, long-term reliability, and life-cycle economic constraints. Emerging directions, including artificial intelligence-driven optimization, digital twin-enabled lifecycle management, intelligent material design, and Food–Energy–Water Nexus-oriented coordination, are further discussed. By establishing a mechanism-to-system analytical framework, this review bridges the gap between fundamental energy conversion processes and engineering-scale implementation, providing new insights into the design and optimization of efficient, resilient, and low-carbon solar desalination systems.
