Experimental characterization of a solar still integrated with a spiral collector using energy, exergy, economic, and environmental (4E) analyses

In this study, an efficient and innovative flat-plate spiral solar thermal collector is integrated into a conventional solar still (CSS) system to substantially increase the potable water without increasing the associated cost. The integrated solar still is experimentally characterized in its daily operation using a complete energy, exergy, economic, and environmental (4E) analyses. The performance of the integrated solar still is compared with two other cases, a conventional solar still and a solar still linked to an internal condenser, for various saline water depths and volume flow rates of the collector and condenser. The results show that the total productivity of potable water around 24 h for the new system is 7325 mL which is significantly higher than that of the conventional solar still (860 mL) and the solar still with an internal condenser (1895 mL). Furthermore, it is found that the daily energy (exergy) efficiency of the proposed solar still is 17.23 % (2.77 %) higher than that of the conventional system. In addition, for the introduced system, the energy payback time decreases by 1.58 years and CO2 mitigation increases by 3548.6 kg compared to the conventional system.