This research was conducted in collaboration with the Botswana Technology Centre (BOTEC) which has since been incorporated into a new research and development institution. The research was conceived as an offshoot of another project, the Solar Chimney, whose aim was to have a working short solar chimney constructed and installed in a remote village in Botswana by 2016 [website: botec.bw (2013)]. This research is on the development of an appropriate solar thermal storage that could be incorporated into the Solar Chimney design. Several concepts have been considered both in terms of geometrical design and storage media. The proposed thermal storage model is based on a sensible thermal storage technology employing water ethylene-glycol at 50% concentration and employs thermosyphon and reverse thermosyphon in the charging and discharging modes respectively. Computer simulations over more than 24 hours have been performed. A physical prototype has also been constructed and testing is currently being undertaken. The proposed storage concept is also likely to find application in other solar thermal technologies that require thermal storage for effective operation; such applications as space heating and ventilation for comfort in residential buildings, crop drying in agriculture, etc.
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