Study on the comparative performances of the solar stills with two different condensing glass cover shapes

• The experimental investigation is conducted on a solar still with an arc-formed glass cover. • The yield of the solar still is improved by 11.9 % and 12.2 %, respectively, at 20 mm and 25 mm water heights. • An improvement of 4.5 % and 4.6 % in energy efficiency is attained at 20 mm and 25 mm water heights. • The higher productivity is obtained with the solar stills at lower water masses. In the current scenario, the desalination of brackish water using an inactive solar still has been considered as a feasible, cost-effective solution to face the challenge of scarcity in freshwater. However, the insufficient productivity of such solar stills is hindering the practical, large-scale application of such stills. In this study, a solution for improving the productivity of a conventional solar still (CPSS) is analysed by modifying the design of the condensing glass. Two stills, one conventional (CPSS) and the other with arc-shaped condensing glass (AFSS), were investigated, and the results were compared. Further, the effect of water height on the performance of the solar stills is assessed. The results demonstrated that the modification of condensing cover augmented the productivity of the still by 11.9 % and 12.2 %, respectively, at 20 mm and 25 mm water heights. The daily efficacy of the CPSS and AFSS were recorded as 40 % and 44.5 % with 20 mm water heights. In addition, the stills with 20 mm water heights showcased better performance compared to the same stills with 25 mm water heights.