Wind generated turbines, solar panel, and hydroelectric power are existing examples of renewable energy that are proven and need to be implemented more. Now there is a renewable source of electrical energy being tested in Norway that is different from all the existing models of electrical power production.
Europe's largest renewable energy company, Statkraft, has recently started a small pilot project in Tofte, Norway using osmotic power to produce electricity. Small may be an understatement, as the total power output currently is merely 4 kilowatts. Not a major impact toward European power, but this unique system is in the experimental stage.
How Osmotic Power Works
This system was conceptualized in the 1970s by Sydney Loeb, an American professor. But the technical wherewithal for exploring the concept further was not available then. Perhaps the motivation at that time was lacking also.
Osmotic power is created by forcing seawater and freshwater through pressure chambers divided by polymer membranes. The seawater salt molecules draw the freshwater through the membrane creating a pressure on the seawater side equivalent to the pressure of a 120 meter (394 feet) waterfall. Such a waterfall would be appropriate for a hydroelectric power generating system. But it's this pressure that is converted in the osmotic pressure chamber into energy for turbines to create electricity with this experiment.
Another way osmotic power differs from hydroelectric power plants is that there is no need to build a dam or locate the plant near a waterfall. It would be necessary, however, for osmotic power plants to be located wherever freshwater rivers meet bodies of seawater. Evidently, this is common in Europe.
The Technological Breakthrough Enabling This Experiment
Despite the minuscule power output from the current tiny experimental plant Statkraft's vice president Stein Erik Skilhagan is confident of the project's future. He feels that because of breakthroughs with polymer membrane technology, osmotic power will advance more quickly than solar and wind energy sources did from their inception. The projected future production of electricity from osmotic power for Europe is equivalent to China's use of electrical power in 2002.
“The first membranes were really bad and really expensive,” said Statkraft VP Skilhagan in the NY Times. “Now, partly due to their extensive use for reverse osmosis in desalination plants, the membranes, which are made from different kinds of polymers, have improved.” In other words, one ecological concern lead to the progress of generating electricity with a another renewable non polluting energy.
The increased scarcity of freshwater for agriculture, animal, and human consumption was the mother of invention for improving desalination technology. So the original breakthrough for adequate polymer membranes were used in chambers that convert seawater into freshwater. This is the improved membrane technology Skilhagan mentioned. The polymer membrane breakthrough for desalination plants was just what Statkraft needed to try out Sydney Loeb's concept for osmotic power production in the real world.
Another Cooperative Possibility for Improved Power Production
The California company that made the polymer membrane pressure chambers for Statkraft is Energy Recovery Inc (ERI), which has been mostly involved with desalination technology. Rick Stover of ERI suggests that osmotic power plants could improve their efficiency if they locate near desalination plants.
The desalination plant's process of extracting freshwater from the ocean creates a byproduct of seawater "waste" seawater with a higher saline ratio. Using that seawater, a nearby osmotic power plant's energy exchange pressure chambers would create higher pressure because of the increased salt content. This would result an increase of the osmotic power plant's production of electricity.
Source: The New York Times, Energy and Environment section article November 24, 2009, "Osmotic Power Debuts in Norway" by Kate Galbraith
Paul Louis - Paul Louis has written several articles for a variety of subjects. He has retired from the mortgage - real estate madness in the USA and ...
