full at source: Scientists have already designed several techniques in an attempt to harvest this energy, and have successfully generated power of about 1 kW for a fresh water flow of 1 liter per second. But these techniques are usually based on membranes through which the water flows, and problems such as high membrane cost and short lifetime are currently preventing the large-scale utilization of these techniques.

Now, Doriano Brogioli of the University of Milan Bicocca in Monza, Italy, has taken a different approach to extracting energy from salinity difference. As Brogioli explains in a recent issue of Physical Review Letters, the method is based on electric double-layer (EDL) capacitor technology.

Hydro electric plants have been used the world over many in Scotland.Harness the power of nature...Wind and water,rivers and the seas but not those ugly wind turbines please.