The osmotic power plant generates power by exploiting the energy available when fresh water and seawater are mixed. Osmotic power is a renewable and emissions-free energy source that Statkraft has been researching into for 10 years and that could be capable of making a substantial global contribution to renewable energy production.
"In an era of major climate change and an increasing need for clean energy, we are proud to be presenting a renewable energy source which has never been harnessed until now," says Statkraft CEO, Bård Mikkelsen.
The prototype that will be opened at Tofte on 24 November has been in development for more than a year. The osmotic power plant will have a limited production capacity and is intended primarily for testing and development purposes. The aim is to be capable of constructing a commercial osmotic power plant within a few years' time.
The osmotic energy is based on the natural phenomenon osmosis, defined as being 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 utilised 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 utilised in a power generating turbine, according to Statkraft.
The global potential of osmotic power is estimated to be 1600-1700 TWh per annum, equivalent to 50% of the EU's total power production. Osmotic power plants can, in principle, be located wherever fresh water runs into the sea; they produce no noise or polluting emissions and they can be integrated into existing industrial zones, for example, in the basements of industrial buildings.
Statkraft has been researching osmotic power since 1997 and has developed this prototype in cooperation with R&D organisations from many countries. The project has attracted a lot of interest both in Norway and abroad.