Thermocline driven desalination: status for Cape Verde

The natural ocean thermal gradients in many areas of the world can be used to efficiently produce desalinated water for consumption and other uses, and the cold seawater constitutes a valuable resource for other applications such as air conditioning and aquaculture. A thermocline driven desalination (TDD) system is being developed for the Republic of Cape Verde, which has the key attributes of warm surface water and nearby deep cold water. The system uses an advanced multistage-flash (MSF) evaporator for the distillation process and large diameter polyethylene pipes for warm and cold seawater supplies. Although the initial capital costs are higher than for conventional desalination facilities, the lower power requirements for the TDD system result in much lower operating costs that make it an attractive economic option. Another important advantage is that dependence on imported fuel is significantly reduced