A review on phase change materials in different types of solar stills

Phase change materials (PCM) can store heat owing to their high latent heat and release it after sunset, thereby increasing productivity during the night. Several studies have been conducted to improve the performance of these systems using PCMs. This paper presents and discusses previous studies that investigated the effect of using PCMs as a heat storage medium on the performance of the system. In addition, utilizing other performance improvers, such as different nanoparticles, wick materials, fins, and reflectors along with PCMs, improved the system's performance. The use of latent heat storage materials led to productivity enhancements ranging from approximately 6.5 % to 783 %. Copper (II) oxide (CuO) nanoparticles and wick solar still gained substantial productivity by 113 % and 202 %, respectively. The use of reflectors also increased energy performance by over 100 %, while installing an external condenser improved productivity by 120 %. Furthermore, drum solar still productivity reached 320 % when nanocoating, a parabolic solar concentrator, and external condensers were used. In this review, solar stills are classified based on their structure, and this point of view can be a new attitude among other published articles in this field. Based on the analyzed issues, suggestions and concluding remarks are presented.