Performance Characterization of a Simple Solar Still Used for Water Disinfection

Solar stills can be used as a way to distill water for drinking. A typical solar still is covered by glass, but since this project is designed to be used in a developing country where glass is not readily available, food film was used as a cover. This paper will characterize a correlation between global horizontal insolation, ambient temperature, and water output of a simple solar still. Using a CR1000 writing panel data logger, these variables were collected hourly and recorded. The global horizontal insolation was normalized to account for the angle of incidence from the sun with a DISC program in Excel. The solar still was designed to be a simple solar still with an incline of about twenty degrees. It was built with plywood and covered with plastic wrap to encourage radiation absorbance as well as keep the plywood dry. Results demonstrate that global horizontal insolation and temperature both have a positive correlation with the water output of the solar still. When both of the variables are high, they synergize and produce more water. The only exception to this correlation is when the temperature is higher than thirty three degrees Celsius, which leads to a decrease in output, and can be accounted for by the water's inability to condense on the plastic wrap at that temperature. This data shows that solar stills would be able to distill and produce clean water for areas with high temperature and solar radiation such as desert type climates.