Mimicking Photosynthesis To Split Water 257
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.
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.
Re:Logic, in my Slashdot article? (Score:3, Funny)
Well, there went the logic.
Re:Logic, in my Slashdot article? (Score:2)
Oxygen and HELIUM ?
All that's good for is filling balloons at the fairground.
Re:Logic, in my Slashdot article? (Score:3, Insightful)
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.
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.
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.
Re:Cambrian Explosion of alternative energy techni (Score:2)
How about we let them work out the bugs before posting to slashdot?
Seems a lot of the stories get posted to get into "the media" without having the required science/adverse analysis/hostile counterpoint process done.
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.
Re:Cambrian Explosion of alternative energy techni (Score:5, Funny)
That clearly depends on its tensile strength.
Re:Cambrian Explosion of alternative energy techni (Score:2, Informative)
Re:Cambrian Explosion of alternative energy techni (Score:2)
Seems a lot of the stories get posted to get into "the media" without having the required science/adverse analysis/hostile counterpoint process done.
I like to read the hostile counterpoints here. :)
Re:Cambrian Explosion of alternative energy techni (Score:4, Informative)
What bugs? Did they NOT mimic photosynthisis? - Did you find a methodology error in their paper? Do you know of published contra-evidence?
"Seems a lot of the stories get posted to get into "the media" without having the required science/adverse analysis/hostile counterpoint process done."
The science has been published in a respected peer-reviewed journal and comes from two leading scientific institutions down here in Oz. Did you have some other 'process' in mind?
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.
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.
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.
Re:Cambrian Explosion of alternative energy techni (Score:2)
So far as I understand TFA, the claims of artificial photosynthesis aren't well founded - what they have actually done is to use manganese as a catalyst to improve the efficiency of electrolytic hydrogen generation.
That's good, but the fact that they used manganese doesn't mean it's photosynthesis just because chlorophyll also happens to have manganese in it.
It's just a fancy catalyst in this implementation.
Re:Cambrian Explosion of alternative energy techni (Score:3, Insightful)
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.
Re:Cambrian Explosion of alternative energy techni (Score:5, Interesting)
No, they're starting with the exact same (expensive) membrane used in fuel cells -- nafion [wikipedia.org]. They've just taken this membrane and added a manganese-based catalyst to it.
I'm amazed that most people never point out the huge, glaring flaw in this notion of setting up big solar electrolysis plants in the sunny desert southwest. Let's ignore the problems of how corrosive the released hydrogen is to your system, which usually makes solar electrolysis have short lifespans. Let's do the same with the free oxygen. And the water. And let's ignore algae growth, which is a problem in most systems that mess with water. And let's ignore hydrogen embrittlement when it comes to raising storage and transportation costs. And let's ignore how huge hydrogen storage tanks have to be due to its very low density, a fact that makes the prior issue even worse. And let's ignore that it has a ridiculously low ignition energy, burns in almost any fuel-air mix, readily evolves deflagrations to detonations, pools under overhangs, enters pipes and follows them to their destinations, burns clear and vigorously, and so on. And let's ignore that leaked hydrogen destroys ozone. And let's ignore that fuel cell stacks are quite inefficient, and that a fuel cell stack strong enough to power a car will cost you hundreds of thousands of dollars. We're talking about *consuming lots of water in a desert* -- enough to power vehicles around the world. What the heck kind of plan is that?
Electricity is our common energy storage and usage medium. Why are we talking about "very low" efficiency, in-the-lab, probably horrible lifespan and very costly hydrogen-solar cells when we could put photovoltaic cells or solar thermal on the same land, get much better effiency from a much cheaper system, transmit the electricity efficiently (92.8% average in the US), rectify it efficiently (~93% charger efficiency), charge/discharge it efficiencly (96%-99.9% in li-ion), and convert that to kinetic energy efficiently (85-90% typical electric motor efficiency in a normal drivecycle), in a vehicle that uses batteries that cost *literally* an order of magnitude less than said fuel cells, can level-3 charge in as little as 5-15 minutes (depending on the type), and have longer lifespans to boot?
The "hydrogen economy" is just a silly concept; nothing about it makes sense in comparison to an EV economy with modern automotive li-ion batteries.
Re:Cambrian Explosion of alternative energy techni (Score:4, Funny)
Good luck raising cash for investment while being extremely sober in your analysis!
Re:Cambrian Explosion of alternative energy techni (Score:2, Funny)
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 is why these vapourware stories are so useless.
According to your first point, these stories would be called gasware stories instead of vaporware stories.
Re:Cambrian Explosion of alternative energy techni (Score:2, Insightful)
Re:Cambrian Explosion of alternative energy techni (Score:3, Informative)
Yes [sandia.gov], there [treehugger.com] is [pesn.com].
Not saying this discovery wouldn't be useful, though.
Re:Cambrian Explosion of alternative energy techni (Score:2, Interesting)
Re:Cambrian Explosion of alternative energy techni (Score:4, Insightful)
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.
Re:Nope... (Score:2, Interesting)
Correct except you've forgotten about the Corona Problem. The Sun's corona is more than a million degrees and nobody knows why yet. Probably some magnetic field effect, but if we can harness the effect and keep it going much further out from Sol, we can heat all the water you need.
It would work just like Doc Smith's Sunbeam, except you wouldn't be shooting at inertialess planets (much).
Re:Nope... (Score:2)
I never said you could reach the sun's temperature. I claimed you could reach 2500 C , which is less than half the sun's surface temperature.
Re:Cambrian Explosion of alternative energy techni (Score:2)
The difference is that the technique you're describing, while it would work, would be very difficult to improve the efficiency of. The technique described in the article has a pre-existing example of a high efficiency implementation.
let the development guys have this tech (Score:2)
The problem is that you're actually talking about two different things. One is a power plant, one is a fuel source.
I submit that if you could use this process to economically produce hydrogen and oxygen, you could create power plants that use these as fuel, and possibly create electrical energy better than nuclear or coal. Better due to greatly reduced environmental impact.
And fuel cell cars are known to be feasible right now, the main problem with them is finding an economical, non-fossil fuel source for the hydrogen.
Another use for this technology would be a sort of energy pack that goes on the roof. A water line goes in, hydrogen comes out and is stored in a fuel cell which powers the house. Problem is what to do with all the waste oxygen.
Re:let the development guys have this tech (Score:3, Informative)
Another use for this technology would be a sort of energy pack that goes on the roof. A water line goes in, hydrogen comes out and is stored in a fuel cell which powers the house.
Fuel cells don't store hydrogen - they use it as fuel. Hydrogen storage is a can of worms entirely separate from the fuel cell that has its own challenges.
Problem is what to do with all the waste oxygen.
Um, what problem ? You either store it, too, and use it when your fuel cell generates electricity, or you just release it into the atmosphere.
Re:Cambrian Explosion of alternative energy techni (Score:3, Insightful)
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.
Re:Cambrian Explosion of alternative energy techni (Score:3, Interesting)
I agree with you. How about these guys?
http://web.mit.edu/chemistry/dgn/www/research/e_conversion.html [mit.edu]
They bounced into the news a few weeks ago.
Re: Cambrian Explosion - but, Sweet Saudi crude... (Score:2)
On a slightly less silly note, I like this development. And wierd body plans suit the laboratory environment quite well.
I imagine we could move away from the great black poison in the dirt eventually, if our good wierdly-planned bodies in the laboratory keep up the good work.
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!
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.
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.
Re:Cambrian Explosion of alternative energy techni (Score:4, Informative)
We still use JP for our mil vehicles, but we use a lot of NTVs (non tactical vehicles) now which are from I have seen over the last few years a fairly even mixture of gas and diesel.
The stoves, heaters, and yes, we have a/c now in even the training tents, all run off electricity which comes from generators that are fueled by something brought in by contracted companies. Diesel? Gas? I don't know because I haven't seen the paperwork for the contracts. It all depends on who we contract out for the generators and what kind of generators they bring in for us.
I think that was the biggest change in Army ideology over the last 20 years or so... they've shifted a huge portion of the green suiters' work onto civvie companies and contractors.
Re:Cambrian Explosion of alternative energy techni (Score:2)
More importantly, why doesn't my solar cell have wheels on it yet?
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.
Re:Cambrian Explosion of alternative energy techni (Score:3, Interesting)
That is very much how the motor car industry started out - you had well over 3000 startup companies all across North America and Europe, experimenting with the combustion engine, and inventing different improvements (carburettor, cooling fan, 2-stroke, 4-stroke and 8-stroke engines). Eventually, over time they merged together to form larger companies and eventually forming a handful of corporations.
How many solar panels would they need on a car to have a completedly closed system (solar panels to generate electricity to split water into hydrogen, a compressor to force the hydrogen and oxygen into the engine, and a collector to recycle the used water from the exhaust)?
Re:Cambrian Explosion of alternative energy techni (Score:3, Informative)
You can't really run a car with solar panels on the car, for a thousand obvious reasons. You can, however, run a car with solar panels covering the parking space you have at home and at work (at most lattitudes, anyway) if you can store that power densly and safely, and transfer it quickly. Plus you'd get covered parking.
The total area of parking spaces in America, if covered with the best existing technology solar cells, would on average cover all of our elecitrical needs, or the needs of the daily commute. It's making the *average* power useful that's the biggest hurdle.
In more realistic terms, we'd be much better off trying to convert our transport infrastructure away from deisel than cars from gas, but you'd need an alternative that was actually practical, not just fashionable.
Re:Cambrian Explosion of alternative energy techni (Score:2)
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:3, Informative)
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".
Efficiency... (Score:2)
What I'm wondering is, is it any more efficient than using the 1.2 volt potential to just electrolyze the water?
need to bring down cost too I bet. (Score:3, Interesting)
Why not just put in a solar panel? 3x the efficiency of the best plants and none of those messy chemicals, plus much better applicability.
Re:need to bring down cost too I bet. (Score:3, Informative)
Because normal electrolysis of water isn't very efficient at producing hydrogen.
This is a system for generating Hydrogen which can then be stored and used as a fuel either in an internal combustion way or with a fuel cell.
Solar panels are a way to generate electricity which then must be stored and used. Storage of electricity is generally a pretty big inefficiency, and solar panels only really work when the sun is out, so they necessitate storage or supplemental energy generation systems.
Re:need to bring down cost too I bet. (Score:2)
The normal electrolysis of water efficiencies usually reported includes the losses that go into generation of electricity. If you don't have that step (like with a solar cell that is generating electricity) the efficiency is pretty good (50-80%).
Re:need to bring down cost too I bet. (Score:3, Interesting)
I've got sunlight and I want hydrogen. Whoops, the inefficiency in the solar cell is still part of the process.
Re:need to bring down cost too I bet. (Score:3, Insightful)
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.
Trade efficiency for storage (Score:2)
I imagine that this new method might find applications where there is plenty of both sunlight and water. Perhaps large ocean liners, and offshore drilling rigs.
Re:need to bring down cost too I bet. (Score:2, Funny)
Because you are only truly green if you do it like the plants!
Re:none of those messy chemicals? (Score:5, Funny)
You don't win friends with salad.
Not as good as advertised. (Score:3, Informative)
Re:Not as good as advertised/ Fixed URL (Score:4, Informative)
Voltage != energy (Score:4, Interesting)
If you had to apply a potential of 1.2V to catalyse the reaction then that is OK so long as the process is chomping very little current and is instead getting the bulk of the energy from the light.
Of course if it is using a lot of electrical energy and just a small amount of light energy then it isn't really much improvement over electrolysis.
plants can split molecules? (Score:4, Funny)
they must be working up to the atom. this means war! bomb the crap out of those planty bastards.
Holy Grail - stored energy direct from sunlight (Score:2, Informative)
There are three crucially important characteristics here:
(1) stored energy,
(2) direct from sunlight, and
(3) zero carbon footprint.
(1) Is important because:
(a) stored energy can be used as a fuel (in this case, it IS a fuel), and
(b) stored energy can be used at times when the primary source is not available (an energy buffer).
(2) is important because:
(a) only one process is involved. There is no "convert to electricity, then electrolyse water" type of two-step process. Improve one efficiency, and the whole process is improved.
(3) is important because: ... only water. That water is replaced back into the environment when the fuel is eventually burned in a fuel cell. No greenhouse gasses, only gasses which occur naturally anyway.
(a) there is no release of carbon compounds into the environment.
(b) In fact, one could release oxygen and hence replace the role of lost forestation. A double bonus.
(c) unlike producing hydrogen from natural gas, there is no carbon compound as a first source
All three are important because ... it makes for a closed cycle. Energy from the sun (which was going into the planet as heat anyway) is temporarily stored and then ultimately re-released, with people benefitting along the way.
All in all, this is a first but crucially important step on the way to a hydrogen economy, and replacing the oil industry.
Because it is "replacing the oil industry" ... expect to hear a tremendous amount of artificially-generated corporate-origin naysaying over this topic.
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:Photosynthesis is Inefficient (Score:2, Insightful)
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.
Re:Photosynthesis is Inefficient (Score:2, Insightful)
Re:Photosynthesis is Inefficient (Score:2)
Re:Photosynthesis is Inefficient (Score:2)
What about cost ? I'd rather have lower efficiency, if it means it's cheaper per Kwh.
Carbs (Score:3, Interesting)
FTFA: This process of "oxidizing" water generates protons and electrons, which can be converted into hydrogen gas instead of carbohydrates as in plants.
Well, hydrogen is nice and all, but I can see an equally compelling reason to work on generating carbohydrates (preferably edible) with this method instead. Especially in places with no plants where having a food source would be awesome - places like long-range manned space flights, as-yet-un-terraformed planets like Mars, and god-forsaken hell-holes like the middle east and the Sahara.
"Soylent green is...well, it's sunlight and carbon dioxide...and 1.2 volts"
So... what is the efficiency? (Score:2)
They say they need to bring up the efficiency, but I didn't see where they are at. Are they at .1%, 1%... what's up? I think a plant is 10% while a photovoltaic cell commercially available is around 10-20%. Just wonder how far they have to go.
Re:So... what is the efficiency? (Score:2)
photosythesis in plants is no more than 6% (source:wikipedia).
Obligatory Simpsons (Score:2)
Lisa: Dad, look what I made for the science fair!
Homer: What good is that? It just keeps spinning and spinning.
My version of hydrogen fuel- all spin, no substance. (of course Lisa had invented a perpetual motion maching)
The problem is ***NOT*** energy production (Score:2)
It is energy storage.
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.
Re:I'll believe it when I see it (Score:5, Insightful)
Re:I'll believe it when I see it (Score:5, Insightful)
Re:I'll believe it when I see it (Score:4, Insightful)
Re:I'll believe it when I see it (Score:2)
Is there really a difference?
Re:I'll believe it when I see it (Score:2)
Science isn't about creating marketable stuff. Having said that, just take a moment to look around you and compare what you see with how the world was 50 years ago. Just because you don't 'see' technology advance in real-time doens't mean it isn't moving.
Re:I'll believe it when I see it (Score:2)
Or his field is really narrow.
No they don't (Score:2)
Re:I'll believe it when I see it (Score:2)
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" :)
Maybe when we get a Grand Unified Theory... :-)
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.
Re:I'll believe it when I see it (Score:2)
Can you give us an example of something you believe is finished, done, unimprovable?
Re:I'll believe it when I see it (Score:4, Funny)
porn.
everything's been done in porn...
Re:I'll believe it when I see it (Score:2)
Re:I'll believe it when I see it (Score:5, Funny)
I think this is awesome news personally.
Next stop: Cold fusion! :)
Re:I'll believe it when I see it (Score:5, Insightful)
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.
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.
Re:I'll believe it when I see it (Score:5, Insightful)
So indirectly, cows are solar-powered, aren't they ?
Re:I'll believe it when I see it (Score:2)
Re:I'll believe it when I see it (Score:2)
If only they used recycling, by burning the methane they produced, then they might be able to live using LARGE areas instead.
This cow runs on methane and grass!
Re:I'll believe it when I see it (Score:3, Interesting)
Instead of hydrogen, why not just make more efficient hybrids
Because you're still dependent on gasoline, obviously.
The technology is already there,
Hydraulic hybrids are less developed than even EVs and PHEVs, let alone hybrids.
without the need to worry about recycling the Li batteries in existing hybrids,
1) Existing hybrids use NiMH, not Li-ion (and certainly not Li)
2) Li-ion batteries, depending on the type, are either minimally toxic or nontoxic. NiMH should be recycled, although it's not a travesty if you don't. The types that are really critical to recycle are lead-acid and nickel cadmium.
and they are more efficient
Their regen is more efficient than NiMH regen, but not more efficient than regen with automotive li-ions or supercaps. Furthermore, regen is the *only* benefit they give you. Hybrids aren't all about regen, you know; that is just *one* energy-saving technique that they utilize.
Re:I'll believe it when I see it (Score:4, Insightful)
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.
Re:I'll believe it when I see it (Score:3, Insightful)
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.
Re:Water Shortage (Score:2)
Re:Water Shortage (Score:2)
i think when hydrogen burns, it gets converted back into water. You probably would want to use non potable water for this as well, rather than cut into potable supplies.
Re:Water Shortage (Score:4, Interesting)
It's better than that. If you take non-potable water and produce pure hydrogen, then when you burn the hydrogen you get potable water. One popular demonstration of the "greenness" of hydrogen cars is to catch the water dripping from the tailpipe in a glass and drink it. I'd only try that if your hydrogen is pure, of course. ;-)
I still favor electric vehicles over hydrogen, however, at least for the next few decades. Electrics have only one significant problem stopping mass deployment - energy density of batteries. Hydrogen has many - the cost of producing hydrogen, the cost of compressing or liquefying the hydrogen, the impermanence of liquid hydrogen ("venting"), the safety concerns of carrying around enough hydrogen to power a car without a "Hindenburg effect", and the cost of a new infrastructure to transport megatons of hydrogen to fueling stations scattered across your country.
Or maybe that's just my EE degree coming through.
Re:Water Shortage (Score:2)
Hydrogen has many - the cost of producing hydrogen, the cost of compressing or liquefying the hydrogen, the impermanence of liquid hydrogen ("venting"), the safety concerns of carrying around enough hydrogen to power a car without a "Hindenburg effect", and the cost of a new infrastructure to transport megatons of hydrogen to fueling stations scattered across your country.
Or find an efficient way of extracting CO2 from the air or from seawater, and use that and hydrogen to make liquid fuels that are entirely compatible with the existing infrastructure.
Liquid fuels will always be easier to handle than gaseous fuels. And of the latter, hydrogen is one of the more problematic ones.
Re:Water Shortage (Score:3, Interesting)
OK, given that hint I went here [wikipedia.org]. The technology looks reasonably mature (except perhaps CO2 capture from the air), again just a cost issue to get artificial hydrocarbon prices down to petroleum price ranges (easy to say, harder to do :-).
I'm still favorable toward electrics, because we can produce electricity cheaply already from a relatively large number of mature technologies - including hydrocarbon-based fuel cells or engines - and the distribution infrastructure is multi-use (not just for engines).
But again, when you're EE, electricity always looks good. My house in Texas is 100% wind powered (sorry, Kermit, but it is easy being green :-). I even mow my yard with a Black & Decker plug-in mower and plug-in weed eater. Never needs a tune-up, or oil change, or new spark plugs, and it's high power under torque. Given my 45 mile round trip commute, I'm very interested in an electric commuter car.
Re:how about nuclear power ? (Score:2)
They can't ensure 100% safety. I wouldn't want to be in the neighbourhood when a rocket with plutonium explodes. And there is nowhere enough nuclear material to provide for the whole world.
Re:False economics (Score:2)
If you apply this process to make homegrown hydrogen, this would be an advantage; in current conditions, we have to transport our petrol, natural gas, electricty to our houses.
Re:Great (Score:3, Informative)
Making Ethanol only destroys food if you're ignorant of the process.
The waste product from the creation of ethanol is a protein-rich mush that is sold to farmers as -- get this -- food for livestock.
Most people need to actually learn about processes before they start attacking them.
Oh yeah, and water turned to hydrogen and burned would turn into water vapour or condensate, which would re-enter the water table as fresh water. This would, unsurprisingly, have 0 net effect on the amount of water available.