Atmospheric Water Harvesting for Climate-Resilient Water–Energy Systems: A Review of Technologies, Design, Operation and Performance Metrics

• Reviews condensation-based and sorption-based AWH routes for arid and semi-arid climates • Builds a single thermodynamics and heat–mass transfer framework that links climate to feasibility • Compares reported results using aligned metrics such as WHR, UPC, SEC, yield per area, and yield per sorbent mass • Distills engineering limits that control real output such as heat rejection, condenser design, drainage, frosting, cycle timing, and thermal losses • Identifies scale-up priorities including durable sorbent shaping, cycling stability, consistent energy accounting, and product water quality reporting Atmospheric water harvesting captures water directly from ambient air and can support decentralized supply in arid and semi-arid regions where surface and groundwater access is limited. This review surveys the main technology families, condensation systems based on vapor compression and thermoelectric cooling, passive radiative condensation, sorption systems using MOFs, hygroscopic salts, and hydrogels, and hybrid concepts that couple sorption and condensation with solar input, photovoltaics, or waste heat. It links climate conditions to feasibility through thermodynamics and coupled heat and mass transfer, and it compares reported results using consistent metrics that reflect yield, energy demand, and operating mode across single-cycle passive devices and multicycle or assisted systems. It then synthesizes the scale-up barriers that persist across platforms, thermal losses and heat rejection limits, performance sensitivity to weather variability and control, durable shaping and cycling stability of sorbents, and inconsistent reporting of energy use and product water quality for domestic supply and agriculture.