Osmotic power

Statkraft in Norway has, for some time, developed concepts for osmotic power, i.e. the power from the differences in pressure between salt seawater and sweet freshwater, the latter passing through a membrane (see figure below).

The potential is far from negligble. The Norwegians estimate their potential to be 12-25 TWh annually corresponding to 10-20% of their present generation capacity. For Europe, they estimate it to be 200-250 TWh, according to an article in the Swedish magazine ERA.

The same source says that they have managed to boost the membrane capacity from 0.1 W/sqm to 2 W/sqm, and that they aim for 5. The membranes are said to be produced in the Netherlands where there is also a similar idea developed within a project called Wetsus.

(Click image to enlarge)