Enhancement of Yield in Single Slope Solar Still by Composite Heat Storage Material—Experimental and Thermo-Economic Assessment

The main objective of this study is to enhance the yield of single slope solar still by extending the operating time of solar still by utilizing composite heat storage materials in the solar still. In this regard, the effect of the composite heat energy storage material developed by the mixture of beach sand with paraffin wax is investigated. The experiments are carried out in solar still with composite heat storage material (SSCHSM), and results are compared with solar still with sensible heat storage material (SSSHSM), solar still with latent heat storage material (SSLHSM), and conventional solar still (CSS). The outcome of the two days’ results showed that the total yield of SSCHSM, SSLHSM, SSSHSM, and CSS are 2050, 1880, 1420, and 1250 mL/m², respectively, on day 1 whereas on day 2 it is 2950, 2680, 2000, and 1820 mL/m². The thermal analysis results indicated that the average thermal efficacy of SSCHSM, SSLHSM, SSSHSM, and CSS is 21.59%, 19.83%, 14.92%, and 13.16%, respectively, on day 1 and day 2 it is 27.42%, 24.94%, 18.59%, and 16.89%. The economic analysis revealed that the cost per liter and payback month of SSCHSM are $ 0.031 and 6.2 months, whereas the cost per liter for SSLHSM, SSSHSM, and CSS was $ 0.034, $ 0.044, and $ 0.048, respectively. Moreover, the payback period for SSLHSM, SSSHSM, and CSS was 6.8 months, 8.8 months, and 9.7 months, respectively.