Standalone green hydrogen production powered by photovoltaic panels and solar atmospheric water harvesting hybrid system: Experimental investigation

The current study experimentally investigates the performance of a hybrid standalone solar system of atmospheric water harvesting (AWH) and solar photovoltaic powering electrolyzer for green water and green hydrogen production. The system prototype is designed, constructed, and tested under outdoor summer and winter climate conditions of Alexandria, Egypt at different operating and design enhancement conditions. Water electrolyzes concept for green hydrogen production system driven by a photovoltaic panel and silica gel absorption/desorption atmospheric water harvesting solar still concept with insertion of porous sheet metals for freshwater production is performed and evaluated. The results show a rise of the AWH freshwater production of (60% and 120%) and (146% and 260%) in summer and winter, respectively with the insertion of one and two porous metal sheets, respectively. The maximum rise of the AWH efficiency is 82% in summer and 53.4% in winter by using 2 porous metal sheets. The hydrogen production rate of the system in summer is higher than that of winter by about 25%. System efficiency is almost doubled when electrolyzer KOH concentration increased from 4 gm/kg to 12 gm/kg water. The average daily system efficiency of the AWH, electrolyzer, and overall system reaches 11.6%, 65.1%, and 2.6% when operating at a KOH concentration of 12 gm/kg with two porous metal sheets. The study contributes to achieving mainly SDG goals 6, 7, and 13. © 2024 Hydrogen Energy Publications LLC