Solar Energy 257 (2023) 221–230 0038-092X/© 2023 Published by Elsevier Ltd on behalf of International Solar Energy Society. Experimental study of the impact of low-cost energy storage materials on the performance of solar distillers at different water depths Ahmed Kadhim Hussein a , Mohammed El Hadi Attia b , Husham Jassim Abdul-Ammer c , Müslüm Arıcı d , Mohamed Bechir Ben Hamida e, f, g , Obai Younis h, i, * , Raad Z. Homod j , Awatef Abidi k a College of Engineering -Mechanical Engineering Department, University of Babylon - Babylon City – Hilla, Iraq b Physics Department, Faculty of Exact Sciences, University of El Oued, 3900 El Oued, Algeria c Ministry of Industry and Minerals - State Company for Automotive & Equipments Industry - Babylon City – Hilla, Iraq d Kocaeli University, Engineering Faculty, Mechanical Engineering Department, 41001 Kocaeli, Turkey e College of Engineering, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia f Research Laboratory of Ionized Backgrounds and Reagents Studies (EMIR), Preparatory Institute for Engineering Studies of Monastir (IPEIM), University of Monastir, Monastir City, Tunisia g Higher School of Sciences and Technology of Hammam Sousse (ESSTHS), University of Sousse, Tunisia h Mechanical Engineering Department, College of Engineering in Wadi Addwasir, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia i Department of Mechanical Engineering, Faculty of Engineering, University of Khartoum, Khartoum, Sudan j Department of Oil and Gas Engineering, Basrah University for Oil and Gas, Basrah 61019, Iraq k Physics Department, College of Sciences Abha, King Khalid University, Saudi Arabia A R T I C L E INFO Keywords: Solar energy Solar distiller Spherical salt balls Sponges Water depths Water distillation ABSTRACT 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 modifed with low-cost energy storage materials by adding twenty-fve 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 modifed solar distillers. Also, the daily accumulated productivity of modifed 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/m 2 , 1655 g/m 2 , and 1340 g/m 2 for both modifed 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. 1. Introduction The fossil fuels source meets more than 90% of our energy needs at a high environmental cost. For instance, the concentration of CO 2 in the atmosphere has risen from 280 to 370 ppm during the last 150 years, and it is expected to reach 550 ppm this century (Ghodbane et al., 2021a; El Hadi et al., 2022; Ghodbane et al., 2021b). Therefore, there has been a great deal of interest in this subject. However, there is a trend toward renewable energy sources because of the enormous demand for energy and the scarcity of fossil fuels. Solar, wind, and geothermal en- ergy are examples of these energy sources (El Hadi et al., 2021a; Hussein et al., 2016; El Hadi et al., 2021b). These renewable sources can replace traditional fossil fuels and nuclear energy. By 2040, it is predicted to meet half of the world’s main energy demand. Furthermore, renewable energies have the potential to reduce greenhouse gas emissions by around 70% by 2050 (Benabderrahmane et al., 2020; Attia et al., 2021; Hussein, 2015; El Hadi et al., 2021c). Renewable energy has also been * Corresponding author. E-mail addresses: ahmedkadhim7474@gmail.com (A. Kadhim Hussein), attiameh@gmail.com (M. El Hadi Attia), ahmed.hussein.eng@uobabylon.edu.iq (H. Jassim Abdul-Ammer), muslumarici@gmail.com (M. Arıcı), benhamida_mbechir@yahoo.fr (M.B. Ben Hamida), oubeytaha@hotmail.com (O. Younis), raadahmood@yahoo.com (R.Z. Homod), amabedei@kku.edu.sa (A. Abidi). Contents lists available at ScienceDirect Solar Energy journal homepage: www.elsevier.com/locate/solener https://doi.org/10.1016/j.solener.2023.04.013 Received 19 November 2022; Received in revised form 4 April 2023; Accepted 5 April 2023