A newly designed floating solar still with submerged external condenser: 4-E comprehensive analysis

Solar stills are an ecologically friendly distillation system that employs plentiful solar energy to provide a solution to ease global freshwater scarcity. Despite their relatively low cost, the main barrier restricting their practical usage is their low productivity. This research presents a novel attempt to alter the evaporation and condensation mechanisms, thereby improving the efficiency of a double-sloped floating solar still (DSFSS) using air fans (AF) and an external submerged condenser (ESC). To that purpose, for the first time, in addition to the glass covers, an external submerged condenser is integrated with DSFSS, providing a highly effective condensation rate while taking advantage of the surrounding aquatic environment. Experimental findings indicate that both AF and ESC significantly improve the still's performance. A notable rise in the cumulative daily productivity of water, average energy, and average exergy efficiencies reached 14.88 L/m2/day, 45.41 %, and 15.17 %, respectively, compared to the conventional solar still (CST), corresponding to relatively improved percentages of 71.10 %, 70.45 %, and 73.90 %. The anticipated cost of DSFSS-generated water is 0.0059 USD/L/m2, 74.58 % less expensive than CST. The cost of eliminating 15.29 tons of CO2 during a 20-year lifespan was $221.77, indicating another benefit from installing the optimum DSFSS.