Solar powered membrane distillation for sustainable desalination from configuration selection to deployment readiness

Water scarcity is increasingly coupled with energy insecurity, particularly in remote and arid regions where conventional desalination is constrained by electricity demand, brine management, and infrastructure cost. Solar powered membrane distillation (SPMD) is attractive because MD can operate with low- to moderate-temperature heat supplied by solar thermal collectors, photovoltaic-assisted subsystems, waste heat, or hybrid energy inputs. This review synthesizes SPMD from an integrated engineering perspective rather than as a catalogue of isolated technologies. A structured literature-selection procedure was applied using database searches, duplicate removal, keyword screening, eligibility criteria, and a quality check focused on configuration, membrane, module, energy, techno-economic, sustainability, and pilot-readiness evidence. The synthesis shows that DCMD provides simple operation and high flux but remains vulnerable to conductive heat loss; AGMD and PGMD improve heat recovery but typically reduce vapor transport; and CGMD/MGMD concepts attempt to recover internal heat while limiting mass-transfer resistance. The revised analysis further demonstrates that collector choice must be matched to the MD temperature window, thermal storage strategy, module geometry, membrane wetting resistance, and deployment scale. Major barriers are wetting, scaling, module heat loss, membrane lifetime, collector and storage cost, inconsistent reporting of GOR/STEC/LCOW, and limited long-duration outdoor validation. Future SPMD research should therefore prioritize collector–module co-design, durable omniphobic or low-impact membranes, standardized performance normalization, brine-management strategies, and field demonstrations that report reliability under real solar variability.