On Fri, 12 Nov 2010 10:51:43 +0000, Martin Brown
wrote:


http://www.chemie.de/lexikon/e/Reverse_osmosis/

Main problem with it is that it is very expensive in energy usage (but
uses a lot less than the alternatives) - unless you have solar powered
distillation.


This might solve the problem.

http://www.carnegiecorp.com.au/files...10/101028_CETO
3 Unveil_ASX 2.pdf

Start extract

The CETO system distinguishes itself from other wave energy devices by
operating out of sight and being anchored to the ocean floor. An array
of submerged buoys is tethered to seabed pump units. The buoys move in
harmony with the motion of the passing waves, driving the pumps which
in turn pressurise water that is delivered ashore via a pipeline.

High-pressure water is used to drive hydroelectric turbines,
generating zero-emission electricity. The high-pressure water can also
be used to supply a reverse osmosis desalination plant, replacing
greenhouse gas emitting electrically driven pumps usually required for
such plants.

End extract