Development of a Solar Desalination Plant

Abstract

South Africa is predominantly a water scarce country with many parts having limited access to water. Water quality is an additional stressor affecting available water supply. In the semi-arid to arid regions of the country, significant salt loading in water resources occurs where anthropogenic influences can be excluded. Treatment of these water sources to potable levels involves desalination that requires large amounts of energy. Conventional grid electricity sources are not available in many rural areas in South Africa. Many rural communities that do not have reliable access to clean drinking water are situated in geographical areas where the annual solar radiation levels are high and where saline ground water sources are available. A limited number of studies have been conducted on renewable energy and desalination technology pairings in South Africa. The research method adopted was largely exploratory and focused on the development of an economically viable water desalination system utilizing renewable energy. The solar desalination system was designed with the aim of being affordable, durable, sustainable, and practicable and produces water which conforms to national health standards. The design is a solar-assisted distillation system that mimics the natural water cycle to produce clean water from brackish sources through a heat transfer system. The flow rate of the prototype compares favourably with other low volume solar desalination systems developed locally.