The use of a solar chimney to enhance the productivity of a solar still

Abstract

Solar distillation is one of the possible solutions to mitigate both the energy and water scarcity issues in remote areas especially those in hot and arid countries. The main advantages of solar stills include the facts that they are passive, inexpensive to construct and maintain, require very low technical expertise and are reliable. However since the productivity is relatively low when compared to other technologies, solar stills are mostly applicable for decentralised water production to provide water to families or small villages which have access to brackish or seawater. This paper analyses the use of a solar chimney which was used to enhance the convective currents within a solar still. Moreover, a condenser was also installed to improve the condensation process. Condensers in solar stills typically consist of fresh seawater flowing through a bank of tubes. However in the configuration presented in this paper, water vapour was forced through a number of ducts immersed in seawater. This solar still was constructed and tested under natural weather conditions using a typical simple solar still as a benchmark. The paper describes how the solar chimney and condensers improved the efficiency of the solar still.