Sunwater Project - An Innovative Water Desalination System operated with Solar Thermal Energy

The present document is in the field of renewable energies in combination with an innovative water desalination unit (WDU). During this project a future proof and environmentally friendly solar desalination demonstration plant was planned, modelled and simulated in Germany and finally installed in Egypt. This includes a model of the solar thermal system and a model of the innovative water desalination unit, which works with evaporation. Additionally a few measurement and simulation results are presented and discussed. A connection is also given between both aspects. Furthermore a few future prospects are added, which can be used to improve later installations. During this project it was shown, that it is possible to produce freshwater with state of the art technologies by using a solar desalination system. Solar energy can be tapped in a lot of areas to produce enough thermal heat to operate an evaporation desalination unit, which produces high-quality freshwater. The quality is high enough for the daily life in private homes and for the agriculture. If it should be used as drinking water it has to be accumulated with trace elements. During this project different difficult problems were found and solved, which should be taken into account during a later realisation and for a commercial use. One bigger problem is that the sun does not shine the whole day and therefore the produced thermal energy must be stored for a later usage, if the desalination unit should be operated 24 h/d. Another problem is the storage of the heat source itself, because the working temperature of the WDU is up to 95 �C and therefore the long-time storage is very difficult due to heat losses during the night and convection of hot and cold water. Additionally it is very difficult to adjust the output temperature of a huge solar thermal field to the desired operation temperature. Finally the present document shows an innovative way for a worldwide future-proof freshwater supply, but the complete system is still optimisable and it could be very interesting to add new aspects in future projects