Design, fabrication, and experimental analysis of improved stepped solar still

In this study, a new desalination system, called an improved stepped solar still, is proposed to desalinate saline water using solar energy. This desalination system is created by adding a separate but integrated condenser to a standard stepped solar still. The condenser space is connected to the desalination section by two air gaps at the bottom and top of the absorber plate. Air circulation between the two parts occurs naturally (free flow). To compare and evaluate the performance of the new desalination systems, a standard stepped solar still was built with the same specifications and dimensions. The two solar stills are tested and compared in a few days of spring (June 11 and 12) and in a few days of autumn (October 10 and 11). The experimental results show that the improved stepped solar still has a better performance than the standard ones so that the freshwater produced by improved solar still is between 76 to 127% more than the freshwater produced by the standard ones. The maximum daily amount of freshwater produced by the improved solar still per square meter of occupied area of solar still area equals 4.57 liters.