A cheap method of improving the performance of roof type solar stills

• Published in: Solar energy Vol. 23; no. 3; pp. 271 - 272
• Main Authors: Akinsete, V.A., Duru, C.U.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1979
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/0038-092X(79)90166-X

The paper presents the results of a test comparing the performance of two types of roof type solar stills. It is reported that the use of charcoal to line the basin of a typical still results in improved productivity. The charcoal is used to reduce the thermal inertia of the still, which is possible for the following reasons: (1) charcoal exhibits capillary action and is hence capable of maintaining a wetted surface whenever it is partially immersed in a liquid; (2) charcoal absorbs incident radiation, and (3) the rough surface scatters rather than reflects incident radiation which reduces reflected losses. In conclusion it is noted that the production rate is increased the most in the morning and on cloudy days when values of direct radiation are low.