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| Science & Technology | |
| Power plant uses salt to make electricity | |
| 2009-11-24 | |
| NORWAY unveiled the world's first osmotic power plant overnight, harnessing the energy-unleashing encounter of freshwater and seawater to make clean electricity. "While salt might not save the world alone, we believe osmotic power will be an important part of the global energy portfolio," the chief on state-owned Statkraft, Baard Mikkelsen, said. Statkraft, which presents itself as the biggest renewable energy company in Europe, is running the osmotic power plant prototype on the banks of the Oslo fjord, about 60km south of the Norwegian capital. Osmotic energy is based on the widespread natural phenomenon of osmosis, which allows trees to drink through their leaves and plays on the different concentration levels of liquids. When freshwater and seawater meet on either side of a membrane - a thin layer that retains salt but lets water pass - freshwater is drawn towards the seawater side. The flow puts pressure on the seawater side, and that pressure can be used to drive a turbine, producing electricity. The point of osmotic power is "to use power not against nature but with nature", summed up Sverre Gotaas, in charge of innovation and growth at Statkraft.
Although the plant will for now produce just enough electricity to power a coffee-maker, it could prove to be a great potential clean, environmentally friendly power source. Statkraft hopes to start building the first commercial osmotic power plant, which would have a 25 megawatt capacity, enough to provide about 10,000 households with electricity, in 2015. | |
| Posted by:tipper |
| #13 Y'all have jogged a memory and transformed it into an idea. My brother was stationed in Germany, while there he got a chance to tour a salt mine. So, just how did it get there, I asumed that millenia ago it was the bottom of a salt marsh or land locked sea Like the Dead Sea, BUT What an idea, to bury unneeded salt in old worked out mines. Hmmm. |
| Posted by: Redneck Jim 2009-11-24 23:10 |
| #12 convert the water to vapor, minus the salt. Just the opposite. The "salt" is vaporized using 30 times less energy than vaporizing water. From comment #5: Instead of dividing salt water and fresh water, Oasys divides salt water and saltier water. This saltier water is water mixed with a unique type of salt called thermolytic salt, in this case comprised of ammonia and carbon dioxide. These salts, when heated, turn to gas. This extremely salty solution draws fresh water from the industrial wastewater or seawater through the membrane, leaving brine behind. Then a small amount of heat is applied to the thermolytic mixture, boiling away the ammonia and carbon dioxide and leaving fresh water. (The ammonia and carbon dioxide is then recombined into a salt to repeat the process.) |
| Posted by: ed 2009-11-24 22:11 |
| #11 Um, isn't fresh water supposed to be one of those diminishing resources? Where are they getting an unlimited supply of it? I can't imagine that the power produced will be enough to convert salt water back to fresh, can you? Yes, we'd definitely need some kind of mechanism to accomplish this. But it would have to be huge. Perhaps something that could make gobs of heat that could be captured to convert the water to vapor, minus the salt. Then that vapor would have to be moved somewhere, condensed back into fresh water, and captured, and the cycle repeated. Unfortunately, this method would only contribute to global warming given the scale it would take to pull this off. Any better ideas out there? |
| Posted by: gorb 2009-11-24 22:02 |
| #10 google 'OTEC' lots of info there. a rule of thumb is that it doesn't run on salt water but on temperature differentials. and after taking about 25-30% of the output to run the place the remainder can be sold. and there is fresh water as a salable by-product to boot. |
| Posted by: USN, Ret. 2009-11-24 21:38 |
| #9 Used lutefisk brine...the answer to tomorrow's energy questions...... |
| Posted by: Uncle Phester 2009-11-24 20:45 |
| #8 as for the salt - topsoil for Gaza |
| Posted by: Frank G 2009-11-24 18:02 |
| #7 They could just sell the fresh water to the Saudis... |
| Posted by: 3dc 2009-11-24 17:28 |
| #6 I once lit a small electric light-bulb with a potato. |
| Posted by: Deacon Blues 2009-11-24 16:06 |
| #5 The problem is Work = Force X Distance. I can't see how a membrane can effectively translate the distance portion of that equation. Seems better to run a pipe from a the top of a fjord to the bottom for small scale hydro. |
| Posted by: ed 2009-11-24 13:44 |
| #4 according to this article in Forbes, the Statkraft plant has a membrane that will generate 3 watts per square meter of membrane. That means a huge amount of membrane to get enough electricity to be worth anything. |
| Posted by: lord garth 2009-11-24 13:39 |
| #3 Um, isn't fresh water supposed to be one of those diminishing resources? Where are they getting an unlimited supply of it? I can't imagine that the power produced will be enough to convert salt water back to fresh, can you? ;^) |
| Posted by: AlanC 2009-11-24 13:18 |
| #2 Great! InstaSpammed. |
| Posted by: ed 2009-11-24 12:44 |
| #1 They are really vague w/r to cost, possible environmental concerns. Like what do they do with the salt, minerals extracted? Some of that may be a plus, some not. |
| Posted by: tipover 2009-11-24 12:33 |