Many regions in the world heavily depend on expensive desalinated seawater. Current mainstream desalination technologies (Reverse Osmosis and Multi-Stage Flash Evaporation) can be considered to be quite energy intensive.
Warm and cold seawater are used for the production of clean drinking water by means of evaporation of warm water and condensation using cold water. This production method requires little energy, requires no chemicals, and produces no waste. Compared to traditional multi-stage flash evaporators or reverse osmosis desalinators, this can be an attractive cost effective means of producing fresh water. It is most suitable for use in tropical islands and arid coastal regions, which are generally near a source of deep ocean water and have little available fresh water.