Performance evaluation of interfacial evaporation assisted solar still with patterned floating absorber and external reflectors

The rapid decrease in global freshwater sources, caused by industrialization, population growth and other unforeseen circumstances, demands the necessity of effective desalination strategies. Solar stills, which provide potable drinking water by utilizing abundantly available solar energy and a direct mode of desalination, are viable solutions. However, lower productivity limits the wide range acceptability of the conventional solar stills (CSS). This work experimentally investigates the effectiveness of interfacial evaporation in solar stills by incorporating the floating absorbers. The floating absorber solar still (FSS) is compared with CSS as a benchmark. FSS involves different absorber configurations such as bare, patterned, and multiple absorbers. Further, the effect of top and bottom reflectors (external) on the FSS performance is analyzed. The application of patterned FSS enhances the productivity by 146 % and 46 % compared to CSS and bare FSS. The use of external top and bottom reflectors in patterned FSS (FSS-P-R) enhances productivity by 28 %. The accumulated water yield per day for FSS-P-R configuration is 4.46 L/m² with energy and exergy efficiency of 70.35 % and 5.9 %, respectively. The cost analysis estimates the cost of the produced freshwater for FSS-P-R as 0.018 $/L, recommending the deployment of the FSS with suitable modifications in remote and hot arid regions with abundant sunshine as a promising approach for alleviating the freshwater scarcity.