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Mimicking Photosynthesis To Split Water
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.
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.
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.
Give a man a fire and he's warm for a day. Light a man on fire and he's warm for the rest of his life. - Terry Pratchett
Papers always suggest more work. I've not once in my life seen a paper that said "Nope, that's it, we're done here" :)
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.
When a scientist tells you he has all the answers in his field, he's a liar.
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.
either that or they are trying to sell you something ~
Correct me if I'm wrong, but isn't the idea to be able to store solar energy this way? Even with solar-driven steam turbines, you can't generate any power at night and afaik, there's no effective way of storing energy. Making hydrogen to run fuel cells at night or when extra power is needed wouldn't really compete with any power source, only supplement them.
30 years?
I think that is a bit long. If you think tech takes 30 years from initial lab stages to general practice I think you've missed some history classes. Try reading up on the Manhattan Project and Computers sometime.
While it is true that development can take decades it often goes much quicker.
This doesn't deserve to be in the same basket as cold fusion. 250 000 species of plants can't be wrong!
I’m old enough to remember 16K of memory being described as “whopping”
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.
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.
The sun's surface temperature is more than 5000 C , so the laws of thermodynamics certainly don't prevent you from reaching 2500 C using the light emitted from it.
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.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Sigh!
On a mobile vehicle, if you want to use the energy from sunlight utilising PV cells, then you must (a) have the PV cells on the car, and (b) only use the car when it is sunny.
For practical use, you must have an energy storage mechanism. Batteries currently can store electrical energy directly, but only in miniscule amounts. Not enough to be practical for a car ... the energy density of batteries is too small, and the weight of batteries is too high.
Therefore, on a car, the stored energy has to be chemical ... that is, a car must use fuel.
The only green (zero carbon) way to do that is if the fuel is hydrogen.
If we have hydrogen fuel on the car, then we do not need PV cells.
If we have PV cells in the field making electrical energy (equivalent role to oil rigs), and we make hydrogen fuel from that electrical energy, then there is a double-conversion process that is abysmally inefficient.
Converting solar energy **directly** to hydrogen fuel could perhaps one day become as much as 1% efficient. Since the amount of sunlight that falls on the planet is 15,000 times as much energy as we use in total as a species, then we can easily accomodate a single process which is only 1% efficient to collect that energy.
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.
TANSTAAFL GIGO Acronyms to live by!
The cost of the device is also important. A low efficiency is not a problem if the device is very cheap. If it is cheap enough to for example cover your whole roof with it, you can live with the lower efficiency.
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.
"I assumed blithely that there were no elves out there in the darkness"
There is quite some variation. We are still waiting for the fusion reactors. In regards to the computers, it all depends on what you mean by initial lab stages and general practice. If you consider Babbage's difference engine (proposed 1822) as an initial lab stage and the availability of affordable computers for the masses (1970 sometime), the computers took 150 years.
Cows move about. They get their energy to do so by eating grass.
So indirectly, cows are solar-powered, aren't they ?
The Bigger The Headache The Bigger the Pill
"It's just a fancy catalyst in this implementation."
Hmmm, they invented a novel polymer membrane that mimics "a key process in psynth", wasn't it a novel kind of membrane that made fuel cells possible? IANA Industrial Chemist, their contact details are all over the article.
"That's good"
That's the point! It helps 'self-educated' geeks tell the difference between science, psudeo-science, and hype outside their sphere of expertise (or lack therof), OTOH there maybe no hope for those like the troll who replied above. 'Tommorow' there will be a slashdot story about bigfoot's carcass (or a dupe even?). The less discerning amoung us will be pursuaded by your eloquence to tar everything from bigfoot to the moon landings with the same brush, thus the same crap you rant against will continue to flow.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
You forgot to figure in the cost of producing and maintaining the solar cell.
Your numbers are also highly suspect. Photosynthesis is about 6.6% efficient (http://www.upei.ca/~physics/p261/Content/Sources_Conversion/Photo-_synthesis/photo-_synthesis.htm), but that includes things like the range of light used, canopy shading, and energy required by the plant for growth and maintenance. Your solar cell efficiency certainly doesn't include growth (!) or maintenance, presumably you wouldn't build your photosynthesis cells so they shaded one another, and your solar cell efficiency is probably a peak efficiency under ideal conditions, possibly at the best wavelength.
Besides, photosynthesis is producing sugars, which is a great deal more complex than producing hydrogen. Splitting water is pretty much the FIRST step in photosynthesis, yet the efficiency values are for the entire process. Synthesizing hydrocarbons is something our technology is very, very bad at.
Duh.
No offense, but the MIT is un doubtedly fmailiar with all of the points you raise. The reason why this technological development is interesting is not because it is revolutionary, but because it is cheap as well as efficient.
If your read the article, you'll see that whole point is that they've found a way to electrolyze water at room temperature with inexpensive materials. Previously, electrolysis required high temperatures and/or expensive catalysts like platinum for the annodes. Well, that's a pretty big hudrle they've overcome, since high temperatures reduce efficiency (gotta get the energy to elevate temperatures from somewhere...) and obviously cost is a primary obstacle. On this basis, it certainly deserves the title of 'breakthrough', though of course there is still more work to be done.
A-Bomb
I disagree. This plant would be based on ground level. Since helium is lighter than air, and thus rises up, helium at ground level has potential energy, just like a rock at the altitude of 1000 meters would have (to be exact, it's the air the helium displaced upwards that has potential energy).
You could simply release helium under a container roof with a chimney. Being lighter than air, helium would rise upwards, and all you'd need to extract power would be a turbine in the chimney.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.