A step forward for renewable energy:
World's first osmotic power plant opened
Over a decade of research has gone into the Statkraft pilot plant for osmotic power production. Opened 24 November, the facility is undergoing thorough testing - to pave the way for commercial production of osmotic power in the near future.
Her Royal Highness The Crown Princess Mette-Marit officially opended the world's first osmotic power plant. (Photo: Jan Thallaug/STATKRAFT)
Utilising the process of osmosis to generate electricity has long been a distant vision. For most, it has remained a mere pipe dream, but a group of osmotic power researchers at Statkraft has persevered since 1997. Statkraft, fully owned by the Norwegian state, is Europe’s largest renewable energy company.
Harnessing the forces of nature
The key to success with osmosis is in the membrane. An osmotic power plant exploits nature's tendency to seek equilibrium: with seawater on one side of a membrane and freshwater on the other, nature attempts to restore the salt balance by diluting the seawater, i.e. transporting water molecules from the freshwater to the seawater.
The thin membrane is rolled up and installed in large pressure vessels. (Photo: STATKRAFT)
The membrane allows only water molecules to pass, not salt. When more and more water molecules migrate to the seawater side, the pressure rises. Pressure can reach 12 bar, equivalent to a water column of 120 metres or a significant waterfall. This water pressure is used to drive a turbine, which spins a generator to produce electricity.
2,000-m2 membrane
To maximise the surface area across which the freshwater can diffuse
into the seawater, the thin membrane is rolled up and installed in large
pressure vessels. The facility at Tofte, 60 km from Oslo, uses a total
of 2,000 square metres of membrane. The membrane module design allows for ample
membrane contact with the flowing water, with minimal loss of pressure.
From testing to commercialisation
The new facility will now undergo comprehensive testing in order to refine the membrane, gain operational experience and more. Statkraft believes it will be feasible to build a commercial osmotic power plant in a few years’ time.
Statkraft has invested a total of NOK 100 million in this osmotic power technology, developed in collaboration with the SINTEF Group, the Norwegian University of Science and Technology (NTNU) and international research institutions. Public institutions in Norway and the EU have provided half the funding for development investment. The Research Council’s RENERGI programme has allocated a total of NOK 13.9 million to various projects along the way.
A sound investment – with global benefits
The Crown Princess of Norway Mette-Marit officially opened the osmotic power plant. Also in attendance was Norway’s Minister of Petroleum and Energy Terje Riis-Johansen, who is convinced that investing in osmotic power is money well spent. “We need more research on and development of renewable energy,” he stated at the ceremony, “and the costs of such energy need to be reduced.”
The minister is extremely pleased to be able to open the world’s first osmotic power plant just two months after Norway became the first country to begin operating a full-scale floating wind turbine.
The high pipeline pressure from the seawater side of the membrane drives the turbine to generate electricity.
Frederic Hauge, president of the environmental organisation the Bellona Foundation, sees worldwide promise in osmotic power as a way to lift people out of poverty. At the opening ceremony of the Tofte facility, Mr Hauge praised Statkraft for its courage and willingness to take risks in developing an entirely new osmotic technology.
The global potential for osmotic power is estimated to be 1,600-1,700 TWh annually – corresponding to 50 per cent of the EU’s overall power production. In principle, osmotic power plants can be built at any location where freshwater runs into the sea. The plants emit no noise or pollutants and can be integrated into existing industrial areas, such as in the cellars of industrial facilities.
- Published:
- 01.12.2009
- Last updated:
- 28.10.2010
