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New Power Plant Produces Both Energy & Fresh Water
joshmccormack writes "An article in Sunday's New York Times (Free Reg, mah peeps) tells of how Japanese scientists have found a way to make fresh water and energy from temperature differences in ocean water. This may change the rules of what land is considered habitable, and the value of energy." Fascinating stuff, next step is rumored to be beer and power.
Temperature difference in sea.
the temperature difference is enough to liquify certain gasses, and then expand it again.
Just like the refrigerating unit.
Not to mention the increase of pressure water gets deeper.
This affects not only the athmosphere by releasing ammonia (which is only a minor problem), but also the temperature balance in the ocean. Things such as the major ocean currents are driven by differences in salinity and temperature of the water. The big currents control at least part of our climate - eg. if the Gulf Stream were to shut down (which some think it might all too easily do if the polar ice cap melts), we will probably have a new ice age
And before you start jeering and making stupid jokes about it, remember that only 30 years ago the idea that human pollution could affect our athmosphere and the seas, was regarded as utter nonsense and hysteria.
When I was about ten I read one of those cool-science-futures-for-kids magazines, which showed a floating OTEC with a vertical downpipe - that makes more sense, as it doesn't rely on rare coastal relief. I believe Bruce Sterling's novel Islands in the Net also had similar floating OTECs. Perhaps building such a device of the necessary scale (you have to pump a lot of water around, after all) just isn't economic?
Even if you do get mass OTEC production working, its quite debateable if it's really such a good idea. It's a lot of effort (money, materials, time) devoted to something that doesn't generate a terribly impressive amount of energy, and by its very nature it both warms the deep water and cools the surface water, which will have localised environmental consequences.
I despair that everyone is concentrating on renewable resources while so many people (particularly in hot western US states) live in essentially uninsulated houses with single glazed windows. Biomas, geothermal, wind, solar, and ocean generation are all expensive and uncertain - tripleglazed solarglass windows and super-thick wall insulation are available fairly cheaply right now, are guaranteed to pay for themselves way before a windmill, an OTEC, or even a biomass plant. Yet still we're paying to air condition the sky.
## W.Finlay McWalter ## http://www.mcwalter.org ##
It would be tempting to think of this as a "free" source of energy. We have to remember that we probably can't stick these plants everywhere because the oceans are the engine behind our weather.
I'm sure that anything that's over-utilized is going to damage/change the environment in some way. Amnonia is a great fertiizer for plants and any that is not used could be injected back into the efluent stream and would re-disolve as presure and the cold from the depth increases and although it may cause localized concentrations the net effect would be pretty neutral. A little less neutral would be the gradual warming of deep water and its effect on the local deep water enviroment, but the incredible mass of the deep water would mitigate the effect.
/. because they seem to get real excited over win/lose schemes i.e. We lose, enviroment wins; but this seems much more like a win/win. We tend to forget just how precious things like having available energy and fresh water really is. This looks like it will provide a little of both to people suffering without.
Historicaly I've had fun flaming/trolling the enviro-whacko's on
Sure this isn't a save the Earth over-night thing but it looks like it's at least commercialy viable
Apocalypse Cancelled, Sorry, No Ticket Refunds
More studies are needed, but the real environmental problem with OTEC is not ammonia, nor is it the temperature balance of the ocean. Ammonia would only be released by accident, and even then it wouldn't be much of a problem.
Temperature balance is regulated because hot and cold streams of water leaving the OTEC are mixed, and then discharged by pumping it to a depth of about 60m, where the water temperature is about equal to the discharge temperature.
The real environmental issue is the fact that 99% of the seawater going through the plant is discharged back to the ocean (rather than being evaporated to fresh water). This means that huge volumes of water - thousands of gallons per second - most be pumped to generate a relatively small amount of electricity. The problem is that for every gallon of seawater that passes through, most of the plankton, algae and other tiny sea creatures who live in that gallon don't survive the amazing journey. A 10 MW island OTEC plant would inevitably destroy thousands of tons of biomass at the bottom rung of the local food chain.
how about a kilometer radius circle of glass that sits about 15 feet off the ground with no walls other than support beams, in the middle sits a kilometer high concrete tube, inside of it are multiple generator turbines. as the sun heats up the air underneath the glass, it moves to a low-pressure zone, the top of the concrete tube, where the ambient air temperature is nearly twenty degrees lower than at ground level; and somthing to the effect of 60 degrees (farenheight) difference between the top of the tube and under the glass. they want to build one of these out in the australian desert.
moox. for a new generation.