The energy is based on the natural phenomenon osmosis , defined as the transport of water through a semi-permeable membrane. This is how plants can absorb moisture through their leaves – and retain it. When fresh water meets salt water, for instance where a river runs into the sea, enormous amounts of energy are released. This energy can be utilized for the generation of power through osmosis.
At the osmotic power plant, fresh water and salt water are guided into separate chambers, divided by an artificial membrane. The salt molecules in the sea water pulls the freshwater through the membrane, increasing the pressure on the sea water side. The pressure equals a 120 metre water column, or a significant waterfall, and be utilized in a power generating turbine.
The membrane is the most essential component in the osmotic power system. Statkraft has been involved in the development of suitable membranes through several years, and in 2011 a cooperation with Nitto Denko, a world leader in membranes, were established.