Implementation of New Stepped Square Pyramid Solar Still for Desalinating Seawater in The Climate of Upper Egypt

In the present study, a modified pyramid-solar-still (MPSS) with new multiple stepped basin areas was investigated in the weather conditions of Qena, Egypt, at a location of (Latitude: 26.16°, Longitude: 32.71°). Boosting the output of the pyramid solar still is the primary focus of the proposed strategy. To achieve this, four basins were built and integrated into the pyramid solar still, with their size increasing in proportion to the surface area of the condensing glass. A 25% increase in basin area per square meter of solar still was achieved compared to conventional pyramid solar still (CPSS) with the same condensing cover area. The thermal performance and productivity of the suggested solar still were demonstrated by developing energy balance equations for temperature components and then analytically computing their solutions. The results showed compatibility between theoretical and experimental results. The highest yields for CPSS were 2524 mL/m2, and for MPSS, they were 3415 mL/m2. The stepped area enhanced the yield by 35.3% compared with CPSS. Moreover, the efficiency of CPSS and MPSS was recorded as 23.5% and 31.7%, respectively. Furthermore, the maximum yield of freshwater was obtained for the northern condensing cover, with the recorded value reaching 1174 mL/m2. Distilled water under the proposed system would cost $0.0179 per liter. Finally, the TDS and pH levels are in accordance with WHO recommendations for the quality of drinking water.