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Water Now More Awesome Than Previously Thought
Dan writes "Wired has a great article about a guy who thinks we can provide unlimited energy , accelerate crop growth, desalinize and purify drinking water, obtain health benefits and provide air conditioning, all by pumping up water from the depths of the ocean."
Actually Cornell University is cooled by Lake Source Cooling, and Lake Cayuga, while the biggest finger lake and fairly deep, is nothing all that special. Cornell was able to successfully cut its emissions and energy usage by about 90% with this thing, with no ill effects to the lake. I say that because some locals thought that it would kick up sedament which would cause eutrophication, but this never occurred. Also, people were worried that the warm water being dumped near the surface would impact the lake, but measurements showed that you can't even tell the difference in temperature more than 10 feel away. All in all, it was a really good move by the university. My only regret is that my freshman dorm wasn't hooked up to it so I didn't have any AC in the summer!
If this technology is going to be so successful why isn't being tried all over the place?
Because there are only a few islands throughout the world where it's practical. If you have a continental shelf, it ain't gonna work.
The efficiency of these system is extremely low because the temperature difference is so miniscule. For thermodynamic efficiency purposes temperatures are measured in Kelvin and temperature differences are only a few percent. The maximum efficiency of these plants in an ideal world is only 6%. When you account for the very large amounts of energy needed to pump huge volumes of water, the real efficiency is only 2-3%. This FAQ covers this and other issues.
Yes, you can get energy, but not much.
Two wrongs don't make a right, but three lefts do.
You need to read the facts on the technology, go here:
http://www.ocees.com/
About the sweating of pipes, it sounds a lot like
g ation_History.htm
drip irrigation, pioneered some Israeli.
It's been around since, what, the mid 60's?
Oh, found information:
http://www.netafim.com/About_Us/NETAFIM_Drip_Irri
http://en.wikipedia.org/wiki/Drip_irrigation
Lessee, water converts to steam and might break down, but odds are will recondense into... water. So where are we depleting this source? And if it's temperature, remember that heat rises, so by default (and by convection) this water is its own heat sink.
This sig no verb.
Hydrothermal events (http://en.wikipedia.org/wiki/Hydrothermal_vent) exist in the oceans and pump out water at temperatures very close to, if not, at boiling temperatures. Pumping warm water back into the ocean is not going to make that much of a difference on the oceans.
I think he is counting on inertia, or some more subtle effect I can't think of.
The articale mentions that once the system is primed, it takes very little energy to keep pumping.
Think about it. You're not pumping water up into the air, you're pumping water above other water. Without any pumping, the water will automatically lift the water to, you guessed it, sea level. You only neet to lift it the extra 30 feet to your beach side farm.
Getting the system started probably takes a lot of power as you have to get all the water in your pipe moving fast enough so the water won't warm up by exchanging heat with the outside water, but one it's moving, inertia will help you keep going. You only need to make up for friction, and for the fact that cold water is slightly less dense.
Then again the article mentions that the pipe acts like a siphon, so maybe there is some other effect I can't think of. Maybe the decreased pressure because of the pump makes water freeze and therefore rise? dunno.
For all you Engineering Types, here is a page with an animation which shows the basis for the technology:
http://www.ocees.com/mainpages/Powersystems.html/
It's not untouched by man. From shipwrecks to dumping of garbage to all the usual pollutants, the deep-ocean is most certainly affected by our presence already. Of course, there's nothing new about this, it's just harder to tell when you can't actually visit most of this stuff in person, and have to send ROVs.
As far as benthic thermal pollution, it already exists in the form of deep ocean thermal vents. Of course these are natural, even though they spew vast amounts of sulphur etc. I would suspect the ecosystem down there would handle this pretty well, since by the time the warm water got back down it would be nearly the same temperature as the surrounding water.
Of course, it would be wise to run a full-scale test for a few years to determine the localized impact on the biosphere,(before widely deploying it) but I wouldn't jump to any conclusions until we see the findings.
m-
You catch enchiladas by picking them up behind the head and holding them underwater until they don't kick anymore -VeGas
That's what I assumed at first, too. But according to TFA it allegedly sustains itself like a siphon. It's mostly a one-time problem to get the flow started, I guess... then the siphon does most of the work. (Presumably with some level of ongoing pump assistance.)
If true, that is a truly neat hack.
With reasonable men I will reason; with humane men I will plead; but to tyrants I will give no quarter. -- William Lloyd
The idea has been around a long time but then so has John Craven. Toronto is using the waters of Lake Ontario to provide air conditioning for a big slice of downtown realestate. The big problem with the Great Lakes is the needs of the urban sprawl that circles the Lakes' shores is putting stress on the resource, not to mention the political fray ensuing from many plans to alter the in/out flow of the watershed feeding the lakes. Being Canadian and watching the growing need for water in the US just makes me feel like we're gonna be on top of the quality of life index for a long time to come.
"Academicians are more likely to share each other's toothbrush than each other's nomenclature."
Cohen
The same sort of thing exists in Toronto.
See http://www.enwave.com/enwave/dlwc/
Anyone who has been to Dubai (I spent a few years there) knows that desalinization in such large capacities is both financially and technically sustainable... Irigation is a no brainer... Creating surplus energy, though ??? That does not sound plausible...
Too bad there's not enough water on the planet for this to happen, huh?
-py
There is a global circulation system called "Thermohaline Circulation". Basically some amount of water, North Atlantic Deep Water (NADW), sink around Labrador Sea, due high salinity and low temperature, until sea bottom (or almost there) and then spread around the world following the Stommel-Arons model.
Due mass continuity, some amount of water must source that water and this is made by surface water, which is much warmer than that cold deep water. So, North Atlantic export cold water and import warm one, which means a positive heat balance. Without that, North America and Europe should be colder than they are now. Some people would call that "Climate Changes"! ;)
P.S.: This is only part of the story, where I neglect some "details".
I have never heard of an "ocean engineer," as opposed to chemical engineer or electrical engineer.
Ocean Engineering is a field of civil engineering, which is concerned with construction on coasts or under water. Offshore oil rigs are designed by Ocean Engineers, for example.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
The turbine produces electricity to lower the pressure in the chamber. The warm water loses energy when spins the turbine. If the water loses enough energy, there may be some electricity to power other things.
Well, yes. Yes I have,,,
:-)
The poster's exactly right. Applying both ice and heat to an injury manage the circulation to the area.
When you have an acute injury, say, a sprained ankle, you get an inflammatory response -- swelling. That's nature's way of splinting and immobilizing the injury. That problem is that all that swelling later turns to scar tissue, in essence, crippling you afterwards.
What you're trying to do is to use cold to decrease circulation during the acute phase of an injury (to reduce swelling), and to use heat and motion to increase circulation during the chronic phase (to help break up scarring and create new muscle and bone). The rule of thumb is ice for the first three days, then heat, but really, you want to ice as long as there's heat coming off the injury.
Both ice and heat will make you feel better. In my experience, ice is initially less comfortable, but WAY more effective in the end. And, ice combined with Aleve is even better.
As an aside, ultrasound therapy works the same way as heat, albeit in a more focused and comfortable way. You never want to use it acutely, but for things like old hamstring injuries, it's the freaking bomb.
During rehab, (and frankly, if you're playing competitively, you're ALWAYS in rehab) you end up using both heat and cold. Usually, that's heat beforehand (to increase flexibility and circulation) and cold afterwards (to reduce inflamation from the trauma to old injuries). After a while, you just get used to the routine -- although spending a half hour with your balls in an ice whirlpool is never any fun.
No, I'm not a doctor or a physical therapist, but after a broken leg, a blown hamstring, one remaining ligament between two ankles, twenty five years in the cage, and a trip playing in the World Games, you get to know these things...
Correct. The grandparent poster should read the article and notice that nowhere did it say that the sweat irrigation was to be derived from buried pipes. It even went so far as to describe one of his PVC cold water pipe sweat condensers in detail, noting that it was out in the open.
t ml?pg=3&topic=craven&topic_set=
"Irrigation:
Pipes carrying cold water run beneath fields of crops, sweating freshwater to irrigate plants and chilling their roots, promoting faster crop cycles."
http://www.wired.com/wired/archive/13.06/craven.h
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