Stepped solar still: A review on designs analysis

Abstract

Everyone’s rights to get clean, safe, and fresh drinking water. As we know almost 71% of water covered in the Earth's surface. It may be in the form of oceans (covers almost 96.5% of all Earth's water), rivers, lakes, glaciers, icecaps, and also exists in the form of water vapor as well as soil moistures. The percentage of freshwater on earth is about 3% in which almost 2.5% fresh water is not available (locked in polar ice caps, atmosphere, glaciers, highly polluted, in soil, or lie too deep below the surface of the earth and not to be collected at a reasonable cost. Fresh water is available only 0.5% of the earth's atmosphere. Solar desalination from a solar still is a renewable method used to fulfill the provision of safe water supply in distant locations at a very affordable cost. However, due to its lower awareness solar still technology is not standardized and commercialized. The factors that influence solar still productivity are wind velocity, solar intensity, depth of water, an inlet water temperature, ambient temperature, and absorber plate area etc. ambient temperature, solar intensities and wind velocity are unable to control because these are metrological variables while the left standing variables could be changed to enhance solar stills productivity. Water depth in solar still inversely affects solar still productivity. Investigations suggest that reduction in brine depth productivity increases, because of higher temperatures in the basin. Minimum depth is maintained by stepped solar still, so stepped solar stills can improve the distillate Productivity. Throughout this review, we attempt to study the various types of stepped solar stills.