Enhancing Solar Still Productivity Using Phase Change Material: Experimental Investigation Under The Climatic Conditions Of Benguerir, Morocco
Abstract
Water scarcity is a critical global challenge, particularly in arid and remote regions where access to freshwater is severely limited. Various desalination techniques exist, but many require high energy inputs, making passive solar desalination a more sustainable alternative. However, solar stills suffer from low efficiency due to the intermittent nature of solar radiation. To address this limitation, integrating Phase Change Materials (PCMs) for thermal energy storage has been explored as a means to enhance productivity and efficiency. This study experimentally investigates the effect of varying PCM masses (2 kg, 4 kg, and 6 kg) on the performance of a single-slope solar still, compared to a conventional solar still (CSS). The experiments were conducted in Benguerir, Morocco (Latitude: 32.22°, Longitude: −7.94°), using paraffin wax (RT54HC) as the PCM, placed at the bottom of the stills to improve thermal regulation. The results revealed that PCM mass significantly influences solar still performance. The 2 kg PCM mass demonstrated optimal productivity, achieving a 27.7 % increase in freshwater productivity and improving energy efficiency from 18.95 % to 24.20 % compared to the CSS. Exergy analysis further confirmed that the modified still with 2 kg PCM achieved the highest exergy efficiency of 2.9 %, compared to 2.67 % for the conventional solar still. While higher PCM masses (4 kg and 6 kg) extended nighttime productivity, they also reduced daytime evaporation rates, highlighting a trade-off between PCM mass and overall performance. This study underscores the importance of optimizing PCM mass in solar stills to balance daytime and nighttime performance. The findings provide a basis for the development of scalable and sustainable solar desalination systems, offering practical solutions to address global freshwater scarcity.
Recommended Citation
N. Elmghari et al., "Enhancing Solar Still Productivity Using Phase Change Material: Experimental Investigation Under The Climatic Conditions Of Benguerir, Morocco," Applied Thermal Engineering, vol. 269, article no. 126056, Elsevier, Jun 2025.
The definitive version is available at https://doi.org/10.1016/j.applthermaleng.2025.126056
Department(s)
Chemical and Biochemical Engineering
Keywords and Phrases
Efficiency; Exergy; Freshwater productivity; Paraffin wax; Phase change material; Solar desalination
International Standard Serial Number (ISSN)
1359-4311
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Elsevier, All rights reserved.
Publication Date
15 Jun 2025
