A redesign of a mobile solar water heater for rural housing in Southern Africa

The low-income rural population of Southern Africa faces a daily problem due to the difficulty of collecting and transporting water from communal water sources. Another problem is that the energy sources generally used to heat this domestic water have become scarce and expensive. It was therefore decided to design an affordable device that could assist with the transportation and heating of water in rural areas. The decision was made to use solar power for the water heating. Initial prototypes were therefore designed, manufactured and tested in the early 2000's. It was thereby demonstrated that water could be heated to an average of 60 °C by mid-afternoon. This is beneficial since several micro-organisms, including V. Cholerae, are destroyed after an hour at 45 °C. Water at 40 °C was also still available at 20:00 in the evening. Further design changes were then implemented in 2014–15 in order to address the issues found during this testing phase as well as to reduce the cost per unit of the design. This new design should be able to heat water to an average of 52°C by mid-afternoon and allow water at 40 °C to still be available at 20:00 in the evening.