Novel and low cost designs of portable solar stills Original Research Article

On a micro/domestic scale resource intensive technologies for water purification are not feasible. With a growing cultural emphasis on sustainability, an alternative environmentally friendly approach to purify water on a micro scale is via the solar still (solar distillation). To date the solar still has not been embraced due to high capital costs, low yields, high maintenance and low portability. The project sought to address the aforementioned issues via utilising light weight plastics and mass manufacturing technology. The first stage of the project involved the development of a simplistic computational simulation primarily used to optimise the design parameters. Two prototypes were designed, constructed and tested; a 0.2 m2 Poly Vinyl Chloride (PVC) Pyramidal still (1) and a 0.6 m2 triangular-prism PVC solar still (2). The stills yielded an average of 0.5 l/day and 0.9 l/day of distilled water respectively, with turbidity levels not exceeding 3 NTU. The average cost per litre of water over an estimated useful life of 4 years was $0.046 per litre for the pyramidal still and $0.063 per litre for the triangular prism still. When compared to the cost per litre of bottled water, the results are encouraging for further development of the proposed solar stills.