The principle of harnessing osmosis has the potential to produce enormous amounts of energy anywhere that salt water and fresh water meet. We looked at some of the approaches to turning this theory into reality earlier this year, including Statkraft’s plans to build a prototype power plant. The company’s plans are now coming to fruition with Her Royal Highness Crown Princess Mette-Marit of Norway officially opening the world’s first osmotic power plant prototype on November 24.
The osmotic power plant guides sea water and fresh water into separate chambers, which are divided by an artificial membrane. Salt molecules pull the fresh water through the membrane, increasing the pressure in the sea water chamber. This pressure is then utilized in a power generating turbine.
The prototype has a limited production capacity and will be used primarily for testing and data validation leading to the construction of a commercial power plant in a few years time. Statkraft claims that the technology has the global potential to generate clean, renewable energy equivalent to China’s total electricity consumption in 2002 or half of the EU’s total power production (some 1600 to 1700 Twh).
In theory, such power plants could be located wherever sea water and fresh water meet, such as the mouth of a river. They run without producing noise pollution or polluting emissions and can be integrated into existing industrial zones, perhaps being installed within unused areas of existing buildings.