Solar still basin measurements and liner material variance for improved water desalination efficiency

Abstract

Access to potable water remains a global challenge, and solar stills offer a sustainable desalination solution. Solar stills however have low desalination efficiencies. The impact of basin measurements and liner material variance on their performance have not been evaluated, and this study sought to investigate this through modelling with the objective of improving the performance of a one-slope solar still. MATLAB is employed in the model development and simulations. The developed model is validated using other experiments in literature. The analysis is done with Machakos (1.52°N, 37.2°E), Kenya climatic conditions as a reference. Various basin liner materials including aluminium, synthetic graphite, brass, galvanized iron and stainless steel are examined based on their thermal properties. Different width-to-length ratios ranging from 0.14 to 0.86 are investigated. Basin liner thicknesses of between 2 mm and 6 mm are evaluated. A parametric study is conducted to determine the correlation between liner material thickness and basin dimensions, and their combined impact on freshwater yields. From the results, synthetic graphite had the best performance, followed by aluminium, brass, galvanized iron and stainless steel with efficiencies of 35.04 %, 24.02 %, 17.02 %, 14.13 % and 12.39 %, respectively. Thus, synthetic graphite outperformed aluminium, brass, galvanized iron and stainless steel by 31.4 %, 51.43 %, 59.675 % and 64.64 %, respectively. A width-to-length ratio of 0.45 yields optimal results, while a liner material thickness of 4 mm is found to be ideal across all materials. The parametric study further reveals that width-to-length ratio has a higher significance on freshwater yields compared to liner material thickness.