Solar Still Performance Improvement Using Tar-Coated Blue Metal Stones: Yield and Efficiency Analysis

The lack of fresh water is one of the most common issues people face. Employing a Solar Still (SS) to transform saltwater into drinkable water can reduce the shortage of drinking water. Still, the lower yield of SS remains a drawback. The use of energy storage materials can significantly improve an SS water output. Four separate experiments were carried out: SS, SS with tar-coated blue metal stones at a 1 cm water level (SS+TC-BMS at 1 cm WL), SS+TC-BMS at 2 cm WL, and SS+TC-BMS at 3 cm WL. Additionally, the thermal and exergy efficiency are assessed. The distilled water produced from SS+TC-BMS at 1 cm WL was 3.82 Kg, and SS+TC-BMS at 2 cm WL was 3.29 Kg, representing an increase of 59.4% and 37.2%, respectively, than the SS. The yield during the daytime (7 AM- 6 PM) from SS, SS+TC-BMS at 1 cm WL, SS+TC-BMS at 2 cm WL, and SS+TC-BMS at 3 cm WL were 2.32, 3.49, 2.91, and 2.15 kg, respectively. Similarly, the generation of distilled water at night (7 PM to 11 PM) was 0.08, 0.33, 0.38, and 0.22 for SS, SS+TC-BMS at 1 cm WL, SS+TC-BMS at 2 cm WL, and SS+TC-BMS at 3 cm WL, respectively. Additionally, the SS+TC-BMS's diurnal thermal and exergy efficiency of the SS+TC-BMS at 1 cm WL was 43.3%, and 2.2%, respectively. In contrast, SS's diurnal thermal and exergy efficiency were 30.9% and 1.26%, respectively.