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Mimicking Photosynthesis To Split Water
Posted by
kdawson
on Sun Aug 17, 2008 09:19 PM
from the just-add-volts-and-put-it-in-the-sun dept.
from the just-add-volts-and-put-it-in-the-sun dept.
plantsdoitsocanwe writes "An international team of researchers led by Monash University has used chemicals found in plants to replicate a key process in photosynthesis, paving the way to a new approach that uses sunlight to split water into hydrogen and oxygen. The breakthrough could revolutionize the renewable energy industry by making hydrogen — touted as the clean, green fuel of the future — cheaper and easier to produce on a commercial scale." This was a laboratory demonstration only and the researchers say they need to bring up the efficiency.
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Logic, in my Slashdot article? (Score:5, Funny)
This was a laboratory demonstration only and the researchers say they need to bring up the efficiency.
Shame on you, submitter. This is Slashdot, you're supposed to write a sensational story and let the comments tell us why it actually won't work. If you're going to write things that make sense and treat us like adults, you're missing the entire point.
Cambrian Explosion of alternative energy technique (Score:5, Insightful)
We are in a phase similar to the Cambrian Explosion, when all sorts of lifeforms with weird body plans gave it a shot . . . but which were winnowed down to a few by the time things started to crawl on land. Chances are just a few of the many alternative energy techniques being fooled about with will pan out commercially . . . but this is a necessary process.
Now, cue the cranky "Gee, Slashdot posts stories about dramatic advances in solar energy all the time; why doesn't my car run on solar cells yet?" posts.
Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
It is easy to get a breakthrough in one criteria if you shaft the other ones.
As an example, you could very well produce hydrogen very efficiently from sunlight without any fancy tech by simply focusing enough sunlight to raise the temperature to 2500 C, at which point water spontaneously separates into hydrogen and oxygen through thermolysis. This would be possible completely without moving parts, no toxic materials, and no new technology.
Problem? It would be much more expensive than making hydrogen from natural gas.
This is why these vapourware stories are so useless. There will be a vast number of ways to convert solar energy into hydrogen or electricity, I could start listing various ways to do it in all kinds of elabourate manners, but it does not mean any of them are good, nor does it mean any one of them is likely to be more efficient than simply using a conventional steam turbine and solar concentrators.
Seriously, what you are attempting to beat is something which, depending on temperature achieved, can have up to 40% conversion efficiency, economies of scale, and uses well tested technology. When you can beat solar thermal then you can start trying to have a go at nuclear or coal, which have a number of other advantages. Simply finding yet another way to convert solar energy into useful work is quite a different thing from solving our energy problems.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
This sounds like a bit of a red herring to me.
Are you saying that we should abandon any new idea or technology if, in its infancy, it isn't better than what we already have? I think that would put an end to a great deal of innovation that we could benefit from in the future.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
No, I'm merely saying that the fact that you can invent many different ways of doing soemthing is in no way an indication that fundamental problems with it will suddenly vanish. It is not rational to expect solar to suddenly become a silver bullet merely because there is a lot of proposed ways to make solar cells.
Perhaps an analogy is in order. There are LOADS of ways to convert nuclear energy into electricity. There's turbines, direct electrostatic conversion, magnetohydrodynamics, thermoelectric solid state devices, sterling engines, brayton cycles, thermochemical hydrogen production, high temperature electrolysis, etc etc...
Now despite of this you don't see people randomly assuming the price of nuclear is going to drop by a factor of ten within "a few years", because people know that with nuclear, as with solar, and as with coal, the most efficient ( in watts/dollar terms ) generation scheme is to heat one side of a turbine and cool the other one. The other techniques, while interesting from a scientific perspective, are simply inferior in one way or another. They may be inefficient, fragile, may not scale, may involve expensive materials / maintainence etc...
What gets on my nerves with the way these solar technologies are described as major breakthroughs is that they ALWAYS, without exception, are described as something which will revolutionise the energy situation, without as much as a shed of proof that they will even be economical, durable, efficient... They are always along the lines of "Here is yet another way to use solar energy, IF it turns out to be cheap ( which we have no evidence suggesting it will be ) THEN it will change the world.".
That's not a breakthrough, it's speculation of greener grass with no evidence to back it up.
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Re:Cambrian Explosion of alternative energy techni (Score:5, Informative)
It's pretty obvious you are looking for a different breakthrough and it's a certainty you won't find it if you are unwilling to entertain NEW knowledge that MAY be relevant.
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Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
How about we let them work out the bugs before posting to slashdot?
Two reasons:
1) The possibility is interesting even if the probability is currently uncertain. ("Of what use is a baby?")
2) Even if it was obvious that the process couldn't be scaled up in any economically feasible manner, it's still interesting to some people on a basic science level.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Funny)
That clearly depends on its tensile strength.
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Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
This wasn't an engineering design, it was pure research. "Can we do this?"
The answer is yes. Now the engineers can try to find a way to do it within constraints, whether environmental, economical or both.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Interesting)
Actually, your answer to why your car doesn't run on solar yet is rather simple. Because we haven't needed solar power to win a war yet. Nuclear got everything it needed to get off the ground, working, demonstrated, and dropped. It was needed to fight a war. Radio, space ships, etc? Same things. The US Military is just starting to come to the conclusion that half their vehicles exist solely to deliver fuel and supplies to the other half(the fighting half) and that there is a huge risk in running tankers full of Diesel and gas to forward areas, as they become very easy targets. Destroy the supply lines, and those 70Ton M1A tanks become very large, immobile targets. Add to that, the skyrocketing cost of fuel the military has to buy. (not to mention, the huge costs of keeping 50% of your peopled tied up in support roles).
THat is why the military is starting to look at things like solar, small nuclear plants, etc. They are looking at hybrid vehicles that work like a train, the whole powertrain is electric, powered by a generator. Some of these vehicles are pretty cool, they could sit there and idle at the forward CP, and you just plug all your radios and equipment into the truck. No need to lug a generator with you.
I have a feeling things are going to improve quite quickly over the next few years. Nothing improves technology like fat government contracts!
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Informative)
Gas as in gasoline is rarer the hen's teeth in the US Army, the only place I remember it being used is in the mess for running stoves, ovens, and water heaters; and I retired back in 1985. I wouldn't be surprised if there weren't new stoves that ran on JP4, military jet fuel and or water-clear kerosene by now. Gasoline is just nasty dangerously flamable stuff especially around bombs and bullets.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Interesting)
In the late 1980s a mountaineering stove came out that could run on those fuels - the whisperlight international. Admittedly one of the first of them was hurled into a crevasse on Mt Erebus in Antarctica by a critic. However the later ones were better and there have been lot of other multi-fuel stoves since then.
Parent
Re:Cambrian Explosion of alternative energy techni (Score:5, Insightful)
You know what a joke during the early times of the Newcomen steam engine was? You need three mines to run a steam engine. One mine where you apply it, one coal mine to fire it and one silver mine to pay for it.
Know what? It changed.
If people would've taken the position you have now and ignore Newcomen's development, the industrial revolution would not have happened, at least not in the way we know it. Yes, the steam engine was horribly inefficient and in most cases uneconomical until Watt made his improvements. After that, though... well, you know history I'm sure.
What we have here is not even yet the equivalent of a Newcomen machine. This has a long, long way to go, give it a decade and good funding and this can go a long way.
Parent
Not new (Score:5, Informative)
This was a laboratory demonstration only and the researchers say they need to bring up the efficiency.
There have been numerous such laboratory demonstrations on different ways to produce hydrogen easily. But the attempts to bring up efficiency are just what failed.
Re:Not new (Score:5, Informative)
I don't think so, although I initially thought the same thing.
The MIT process (from July 31 /.):
"..catalyst is made from cobalt, phosphate and an electrode that produces oxygen from water by using 90 percent less electricity than current methods, which use the costly metal platinum."
The Monash team (todays /.):
"..using just sunlight, an electrical potential of 1.2 volts and the very chemical that nature has selected for this purpose". The chemical seems to be "a form of manganese".
Parent
Photosynthesis is Inefficient (Score:5, Interesting)
Photosynthesis has a maximum theoretical efficiency [fao.org] of about 11% from sunlight into energy stored in biomass (eg. the plant). But in the wild, it's only 3-6% efficient.
Familiar PV cells already get 15-25% efficiency; experimental concentration cells get over 45%. And the PV outputs electric current, not just biomass to burn inefficiently.
Those cells cost a lot more energy to make than plants do, but they last over 30 years, while most plants don't.
I'm not so sure that mimicking photosynthesis is such a great way to go.
Re:I'll believe it when I see it (Score:5, Insightful)
Let's give them some credit at least. They've managed a break through in science and just because it's not perfected yet, you feel the need to disregard it completely? They obviously know it needs more work, they admitted so in TFA.
Give 'em a break man.
Parent
Re:I'll believe it when I see it (Score:5, Insightful)
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Re:I'll believe it when I see it (Score:5, Insightful)
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Re:I'll believe it when I see it (Score:5, Interesting)
Nah, after GUT [wikipedia.org] there's still TOE [wikipedia.org] to shoot for. And after TOE we can really start developing theories about parallel universes with twisted GUTs and ticklish TOEs. There's always more work.
And if all else fails, there's always the "soft" humanist sciences. There's as much work there as you can make up.
Parent
Re:I'll believe it when I see it (Score:5, Funny)
I think this is awesome news personally.
Next stop: Cold fusion! :)
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Re:I'll believe it when I see it (Score:5, Insightful)
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Re:I'll believe it when I see it (Score:5, Interesting)
How many plants move around? How many animals use photosynthesis to get the energy to move around? What is the ratio of plannts / animals in the world?
If evolution is a teacher it is telling us that sunlight is so diffuse that you need vast areas of collectors to power even a small number of things that move about. Unfortunately, we want to move a lot of stuff using minimal impact on our surroundings, so we want something less diffuse in nature.
Parent
Re:I'll believe it when I see it (Score:5, Insightful)
How many animals use photosynthesis to get the energy to move around?
Ultimately, all of them.
What is the ratio of plants / animals in the world?
It is extremely high, necessarily.
Compact energy sources are finite and have quite significant impact on our surroundings. In order to move the most amount of stuff possible, humans must learn to disintermediate plants.
Parent
Re:none of those messy chemicals? (Score:5, Funny)
You don't win friends with salad.
Parent