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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.
After reading the headline, the combination of these two things is like starting a company that sells fireworks and flamethrowers... but after reading the article it actually makes a good deal of sense.
sig.
FP? Anyway, I've visited that type of plant (OTEC, Ocean Thermal Energy Conversion) already in Hawaii (near Kona), where there is one running since quite some years. One problem is that it only works for steep ocean wall drop offs, since otherwise the pipe is getting too long.
It uses about half of the created energy (through a normal Carnot cycle) for pumping (about 120kW). The other half is not quite competetive, but with the nutrient rich and cool water, fish farming and air conditioning can be done, heaving the whole investment to a black zero (or better).
I leave the exercise of finding the link to a Karma-hungry reader.
Hurricane Application Group, Dept of Meteorology Control, Ministry of Proactive Defense
Having lived on a island in the south pacific for a year I learned how important fresh water is. The aircraft landing strip that we had acted as a big water collector - water would drain into pipes and then was cleaned by a chlorination process. The idea they propose is a good one and would work in many islands out there - where they desperately need easy access to electricity and fresh water.
I am sure more will be available about the subject at a later date but, here is what would be interesting to know:
+ How much power/water does one of these amonia powered drinking fountains produce?
+ Is it scalable, should I start writing my congress person to de-comission Califoria's oil powered plants?
I heard that in some arabian countries beer is less expensive than water.. In near future this could also allow folks down in US to get their industrial energy(Oil) from somewhere else than Irak? ;)
Strictly speaking, complete combustion releases energy and water (and carbon dioxide), and combustion engines are power plants that have been producing energy and water for quite some time.
Of course the operative word there is complete and as we all know your typical combustion engine passes (at least) a few PPM of unburnt hydrocarbons along with the other combustion products.
There are no karma whores, only moderation johns
The article wasn't clear whether the ammonia is re-absorbed or released into the atmosphere. I'm guessing it would have to be released, otherwise it'd be some kind of perpetual energy system. Assuming that's true - surely this system is just the same as burning fossil fuels? except it's releasing nitrogen based nasties instead of carbon based ones. Or am I misguided again?
It's not only more practical, but also better.
It only disturbs the water temperature in a local area. So at most some fish are dying. (Some other might growing bigger in return as the cooler water tends to have more nutrients)
Not like a fusion plant, that has all those problems radioactive waste is generating. (And the waste from fusion plants is not even useable for building ammunition like the uran is)
Bringing cold water from the depths has an unmentioned potential side-effect. Will it be replaced by warmer water from elsewhere? Cold, deep waters often support amazingly rich ecosystems. Raising the temperature even a few degrees could easily destroy entrie habitats. Will these generators warm the depths, and what effect will that have on the deep ecosystems?
The Moon's gravitational pull? The article isn't /.ed yet you know... ;-)
This system is driven by temperature differences, not tidal movements, meaning the ultimate power source is mostly the sun with some input from the earth's core. AFAIK we don't get much heat from the moon's gravity ... (Just as well, really: any energy we extracted from it would be orbital kinetic energy. Draining that is bad, since it would cause the orbit to decay and squish people.)
In the long term, I hope fusion will be successful; so far, the biggest research reactors only just pass the break-even point (generating more power than they consume), but the difficult bits (getting a reaction going, then feeding fuel in and removing waste while the reaction continues) are just about solved well enough to build bigger reactors. In the short term: fission. Wind and solar still can't produce enough power; oil - well, we know where that gets us! Gas is OK (and at least the US has ample domestic sources of natural gas, so no need to pour cash into Arab states which hate us...) but still produces pollution. Coal is the worst of all: not only does it pollute on a scale normally only seen in nightmares, it even produces more radiation than fission! (All carbon is slightly radioactive, which is how carbon-dating works; when you burn coal by the truckload, all the little bits add up to more than the small amount of uranium used in fission plants.)
So: Kill fossil fuelled powerplants, build more fission, and keep researching fusion. "Renewables" are improving, but still can't do the job properly - apart from anything else, solar and wind power don't even work 24x7, and power storage is nowhere near advanced enough to compensate. So, those nice clean "renewable" plants still need a conventional power station as backup!
OTECs Have great capabilities but have some limitations. The best way to get energy from thermal exchange is by having the greatest temp contrast. Equitorial waters are the most suited. OTEC that use an amonia to enhance the reaction do not leak it out. Basically deep cold water is mixed with warm surface water in a vaccum turning it to steam. The by-products are clean fresh water and hydrogen. Also the water brought up is heavily mineralized which has its uses in secreting a concrete like substance. Sea-Crete as some call it basically is same thing sea shells are. By using iron rebar for instance you immerse it in this heavily mineralized water and apply a slight electrical charge and you can grow this sea shell sea-crete stuff, its not fast but its strong and natural. Theres this group that has a idea of using a few OTECs and building a city near the equator on the ocean. The mineralized water is also usefull in mariculture, aka growing fish and crusteaceans. They plan to grow spirulina on the surface of the mariculture ponds. Spirulina is a plant/algae that when dried to powder is a potent source for nutrients. They think they can make a stable economy for this said city off exporting fresh water, sea foods, spirulina, and the hydrogen which the OTECs are central to producing all those including power in excess. And we all want clean power and hydrogen for those new fuel cell laptops coming next year. Course, if they built it exxon or someone the like would probably run into it and sink it. Or maybe a US submarine??? Though seriously, if the petro companies were real smart instead of fighting and stifling new energy theyd help develop it and get in at the ground floor of a new industry. Rant mode off...Those who use power without wisdom cannot claim courage...
It still is. As it turns out in reality, the 20th century was the one with the least chaotic "earth weather" and we now try to use _that_ as a baseline for "how it should be".
It won't work. The earth has a weathersystem totally independent of what us tiny humans do. Read up on the "small ice age" just a few hundred years ago, or where the "dark middle ages" got the nickname from.
"Global warming" is a myth. A popular one, but a myth nonetheless. "Global cooling" - which was popular a few centuries ago - is actually more likely to happen.
it's in my head
Next to the sun and the wind, the Moon's gravitational pull on the earth is about the only other source of near infinite energy this planet has.
The Moon's gravitational pull on the earth is indeed a renewable energy source... but it's not a resource. A resource is something that is actually worth exploiting. Current experimental tidal power plants are extremely expensive, environmentally disastrous (they kill all the species that feed/lay eggs on the shoreline), and produce pathetically small amounts of energy. Google the Bay of Fundy experiment for more info.
Ocean thermal energy conversion isn't much better than tidal... too low-density and remote to ever be economical.
But you forgot the best renewable of all: GEOTHERMAL! It's good for at least a billion years and there's enough of it accessible within 3km of the earth's crust to power the whole world - ten thousand times over. We just have to wait until the technology catches up so that we can harness geothermal power effectively. When that happens, all this speculation of "wind" and "moon" energy will seem as silly and archaic as Wiccans exploring the healing powers of homeopathy.
One interesting power / water / greenhouse idea I read in New Scientist a while back involoved building a big glass air hanger in a hot climate on a reliably windy spot near the coast - the windward wall was built as a metal framework filled with porous wate absorbant material (straw in the example) which had sea water running down it in a waterfall.
As the hot wind entered the hanger it evaporated a large amount of water, and cooled substantially. The climate within the hanger was therefore wet and cool and sunny - perfect growing conditions (and NOT saline!).
At the far end cool seawater was used to cool a big condenser to get fresh water out of the air leaving the hanger.
The water pumps were relatively slow operating, so could run on relatively crap solar panels.
This idea didn't so much generate energy as avoid the need for the stuff in the production of water - and it enabled the reliable growing of a wide range of crops in an otherwise arrid climate
Not really. Global warming is a fact. Whether or not humans are warming up the place is another thing. Could be the sun is getting hotter, could be our emissions doing it, could be natural climate cycles, could be a precursor to a magnetic pole shift.
The cause does not really matter.
Whatever the cause may be, the climate patterns of several hundred years (as far back as we have fairly complete and accurate data, basically) have changed markedly in the last decade and it seems rather foolish NOT to try and fight that change. Even if it's a totally natural phenomenon, it is still affecting the human population of this planet, not to mention the economic impacts. And if there's the slightest chance that we are causing it, there's even more reason to fight it.
If we are to survive as a species, we need to terraform this here planet a bit.
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I think the DoE deep sixed research on this in the late 70's becasue these would have to be in international waters halfway around the world in order to be effieient.
-=fshalor
I keep seeing people that claim that fusion and fission are the way to go, still I have a question...
:-)
I am absolutly not knowledgeable on the subject so beg with me...
I was reading two link, this and thiswhich kind of explain all this to kindergarden level audience, read fine for me.
And from what I understood, fusion uses both deuterium and tritium at the moment. They state that both are a nuclei of hydrogen.
They go on to say that deuterium can be found in water while tritium can be found in the lithium in the earth crust
First of all, they say that they extract the deuterium from sea-water and lithium from the earth crust/sea water (one says earth crust the other says sea water).
While the amount of energy they can produce with this kind of reaction is very impressive, and the waste is supposed to be 100X less then with fission,
how will they manage to clean it up after 100 years? And how is it renewable energy?
I understand that it is VERY efficient, and I am all for that, just want to know how it is renewable.
And how do they clean up the resulting stuff? Maybe it is 100X less radioactive then the result of a
fission plant, but it is still radioactive none the less, isn't it?
I think that it will be a major breakthrough in the energy field for the generations to come,
but I fail to understand how at mid to long term it will be any more safe then oil.
I know oil is very bad on the environment, but if we managed to get to this point damaging earth with oil in what,
100 years, what does it change if this gets us to the same point in 300 or 400 years?
Maybe it won't pollute air and water the same way, but it still pollutes a lot!
I worry because I think energy is just like bandwidth, the more you have, the more you consume.
and then, you need more. So if it still produce a fair amount of damaging garbage, ain't it bad in the long term anyway?!?
Well, I'm not to coherent this morning, but I am just asking
I'd rather be sailing...