Dual-Stage Atmospheric Water Harvesting Device for Scalable Solar-Driven Water Production

Abstract

<h2>Summary</h2> Recent work has demonstrated adsorption-based solar-thermal-driven atmospheric water harvesting (AWH) in arid regions, but the daily water productivity (L/m²/day) of devices remains low. We developed and tested a dual-stage AWH device with optimized transport. By recovering the latent heat of condensation of the top stage and maintaining the required temperature difference between stages, the design enables higher daily water productivity than a single-stage device without auxiliary units for heating or vapor transport. In outdoor experiments, we demonstrated a dual-stage water harvesting device using commercial zeolite (AQSOA Z01) and regeneration under natural, unconcentrated sunlight where ∼0.77 L/m²/day of water was harvested. Our modeling showed that by further increasing top-stage temperatures via design modifications, approximately twice the daily productivity of the single-stage configuration can be achieved. This dual-stage device configuration is a promising design approach to achieve high performance, scalable, and low-cost solar-thermal AWH.