Depends on the process. Is usually extremely energy intensive, but there are some interesting developments happening. Direct contact membrane distillation - ht

Depends on the process. Is usually extremely energy intensive, but there are some interesting developments happening. Direct contact membrane distillation - http://www.usbr.gov/research/AWT/reportpdfs/report134.pdf http://www.usbr.gov/research/AWT/reportpdfs/report134.pdf Seawater greenhouse - http://www.seawatergreenhouse.com/process.html http://www.seawatergreenhouse.com/process.html