Reducing the Thermal Inertia in a Conventional Solar Still to Increase Productivity

In many arid and semi-arid zones, such as in the Brazilian Northeast, potable water is scarce and people and animals suffer water scarcity year after year. On the other hand, insolation is usually high in these areas, favoring the use of solar stills. However, these stills demand substantial investments, not affordable by most users. One way to reduce costs is to increase the evaporation rate to raise the yield of solar stills. One method of enhancing the evaporation rate is to increase water temperature instantaneously during periods of high insolation by the reduction of the water thermal inertia [8–10]. This work discusses the increase water evaporation rate in a conventional solar still, by reducing the thermal inertia, and the increase in productivity of a Conventional Solar Still, CSS, by wicking. Results from experiments in two different days show that wicking increased the productivity of a CSS, from 17.1 to 19.5%. Knowledge of the mechanism that improves the yield of a CSS, should encourage the use of solar stills to minimize the scarcity of potable water in semi-arid zones.