Experimental study of the impact of low-cost energy storage materials on the performance of solar distillers at different water depths

In the current research, a low-cost energy storage material was utilized to improve the performance of single-slope solar distillers. To this end, a conventional distiller was modified with low-cost energy storage materials by adding twenty-five spherical salt balls and seventeen sponges to the bottom of the basin at different water depths, and its performance was examined under the climate of Al- Hilla, Iraq. Therefore, two cases were tested; 25 salt balls + 17 sponges in 1.5 cm depth of water (Case 1) and 25 salt balls + 17 sponges in 2 cm depth of water (Case 2), and their results were compared with the conventional solar distiller. It was found that using reasonable energy storage materials (salt balls and sponges) has a good role in increasing the productivity of modified solar distillers. Also, the daily accumulated productivity of modified solar still (MSS) for Case 1 was higher than that for Case 2 and CSS by about 16.86% and 44.32%, respectively. The maximum productivity was attained for Case 1, which was 1934 g/m², 1655 g/m², and 1340 g/m² for both modified solar still (MSS-SBS) for Case 2 and CSS, respectively. Finally, it is recommended to use low-cost energy storage materials such as salt balls and sponges with a minimum depth of basin water to improve the productivity of the solar still.