The effect of using different designs of solar stills on water distillation

Solar distillation is one of the important methods of utilizing the solar energy for the supply of potable water to small communities where the natural supply of fresh water is inadequate or of poor quality, and where sunshine is abundant. Solar energy utilization in two different types of solar stills is considered, and factors that influence the productivity of solar stills are discussed. The present investigation showed that the productivity of asymmetric greenhouse type still (ASGHT) having mirrors on its inside walls was higher than that of the symmetric greenhouse type still (SGHT) and more efficient. It was found that the distilled water output of the asymmetrical greenhouse type was 20% higher than that of symmetric greenhouse type. Performance characteristics of the two stills showed that the temperature at the water surface is closely related to the incident solar radiation, and the productivity of the stills can be increased with decreasing water depth, and by the addition of dye.