Norway has become the first country to delve into producing osmotic power, a new, emission-free way of generating electricity.
As the name suggests, osmotic power is created by allowing fresh water and sea water to mix by means of a specially engineered membrane.
If fresh and salt water are channelled into chambers separated by a semi-permeable membrane, the fresh water will travel through the membrane to equal out the difference in salinity on the other side. This increases the pressure on the sea water side, equal to a 120 meter rise in water level and can produce enough power to run a turbine.
Norway’s Crown Princess Mette-Marit, on hand for the grand opening of the osmotic facility, was able to sip a cup of tea made by using osmotic energy.
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.” – Statkraft CEO, Bård Mikkelsen.
The potential for global practical application of this technology is huge, as all over the world, fresh water meets salt water as rivers run into seas and oceans.
Although Statkraft’s inaugural plant will be mostly limited to testing and development purposes, within a few years they hope to be at a commericial power-producing level.
{ 3 comments… read them below or add one }
ase in point, all polyethylene products are supposedly recyclable, yet egg ‘cartons’ cannot be recycled with bottles, even though both are number 1 plastics, because the egg boxes are molded at a different temperature than that of the bottles, and therefore is no longer the exact same polymer.
Photo-degradable plastics (oxo-biodegradable) are supposed to be recyclable, yet there are no facilities anywhere to process them, so they end up in the regular waste stream. Biodegradable plastics cannot be recycled with other plastics since they would render any subsequent product biodegradable (imagine your new recycled plastic lawn furniture crumbling under the summer sun… not pretty).
Personally, I think we should go back to refillable and endlessly reusable glass bottles, filled at a local refilling station, like in the ‘old days’. Cut down on transportation, create new jobs, re-open the bottling plants across thecontinent, including the one in PEI that closed two years ago.
That is very intuitive in design… does it have a near zero energy consumption? Or is there something else I am not thinking of. Where does all the brine go after it become saturated? As for the recovery of the freshwater… does it go straight into a resevoir or does it get pumped to a lake or back to the ocean?
Nice write-up, although there’s a slight error in it: The fresh water passing through the membrane doesn’t actually increase water level in the sea water part of the chamber – it increases water *pressure* to a level that equals that of the downward pressure in a 120 meter high waterfall. The illustration above is conceptual – the actual pressure vessels where the process is taking place are tubes with the membrane rolled up inside. There’s a picture of them in my recent blog post about this – I also go into some other aspects of osmotic power in the post: http://www.renewablesathome.com/energy-sources/worlds-first-salt-power-plant
@Sean B: The energy consumption required to run the plant is quite low – basically a bit of power is needed to pump the water and clean the membranes (as they will pick up small impurities from the water over time).
@SeanB and Michael Mark: The brine is pumped out of the power plant after the energy generation is done. These power plants are basically designed to be located where fresh water is mixed with ocean water anyway, ie. where rivers run into oceans. Putting them elsewhere would be wasteful, as fresh water supply is limited in most parts of the world. Besides, one or both types of water would have to be pumped over longer distances if both weren’t present close to the plant.
As an aside; desalination is often done by utilizing the osmotic process, too, except that pressure is added to the sea water side of the chamber to force water through the membrane, while leaving the salt behind.