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MIT's 'Artificial Leaf' Makes Fuel From Sunlight

Soulskill posted about 3 years ago | from the do-you-think-energy-just-falls-off-trees dept.

Power 158

New submitter nfn writes "MIT has published a new paper (abstract), along with a video of a working prototype, of what they're describing as an 'Artificial Leaf' that separates water into oxygen and hydrogen using cheap, non-exotic materials. 'The artificial leaf — a silicon solar cell with different catalytic materials bonded onto its two sides — needs no external wires or control circuits to operate. Simply placed in a container of water and exposed to sunlight, it quickly begins to generate streams of bubbles: oxygen bubbles from one side and hydrogen bubbles from the other. If placed in a container that has a barrier to separate the two sides, the two streams of bubbles can be collected and stored, and used later to deliver power: for example, by feeding them into a fuel cell that combines them once again into water while delivering an electric current.' No word on the arrival of 'Artificial Salads,' or when any of their other alchemy projects will bear artificial fruit."

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Duplicate (1)

xdor (1218206) | about 3 years ago | (#37569092)

This was already posted on slashdot

Re:Duplicate (1)

Dyinobal (1427207) | about 3 years ago | (#37569258)

ya it's a dupe I'm pretty sure we saw this at least a few weeks if not a couple months ago.

Re:Duplicate (0)

Anonymous Coward | about 3 years ago | (#37569448)

Why yes we *ALL* pay perfect attention to every story that shows up on slashdot. Then if we miss anything we dig thru the old articles to make sure we have an encyclopedic knowledge of everything that has ever been posted.

First I have seen it btw...

Re:Duplicate (0)

Anonymous Coward | about 3 years ago | (#37569502)

That's a bit odd, since the referenced article was published today too. Do you get news before they happen on slashdot and then a dupe when they do?

Re:Duplicate (1)

LifesABeach (234436) | about 3 years ago | (#37570412)

Given that project is a rehash of existing technology published several months ago, is it OK to agree with you? I RTFA, and was hoping that the prototype had gone into production. It appears that the development team is in an endless loop; maybe a business undergrad at Stanford could guide them out? The general business model using this technology was described by Poul Anderson in, "The Boat of A Million Years". It would have been nice if the team had demonstrated something a little more robust, like a collection of these leaves performing some observable task? A positive demonstration, using the same methodologies in the existing leaf technologies, could be to separate Sulfur from Crude Oil? Or TCP's from Ground Water.

no, maybe an update... Re:Duplicate (2)

Fubari (196373) | about 3 years ago | (#37569526)

You're talking about this slashdot entry from 5 months ago: http://hardware.slashdot.org/story/11/03/28/239212/artificial-leaf-could-provide-cheap-energy [slashdot.org]
Not exactly a dup; they link to different articles.
This one's article [mit.edu] has a video showing the prototype in operation, which is kind of cool.
The old one's article [sciencemag.org] has no video, but they basically make the same points in text.

Duplicate (from the 19th century) (1)

bigredradio (631970) | about 3 years ago | (#37569650)

Besides the debate as to whether this is a duplicate story, electrolysis has been around since the 19th century. The only thing here is that they are using solar cells to generate the power. Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

Re:Duplicate (from the 19th century) (3, Funny)

GrumpySteen (1250194) | about 3 years ago | (#37569794)

> Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

That's fucking incredible!! When did they do that?!?! Why wasn't I told????

Re:Duplicate (from the 19th century) (0)

Anonymous Coward | about 3 years ago | (#37570164)

Damnit bigred, you weren't supposed to tell steen!
Well there goes that conspiracy out the door...

Re:Duplicate (from the 19th century) (2, Interesting)

Anonymous Coward | about 3 years ago | (#37569992)

This is, in fact, a revolutionary new catalyst potentially worth billions. It does the same thing as conventional electrolysis, but is more than 20 times as efficient as just sticking two wires into a bucket. When I saw Nocera present this research at the Spring ACS conference, my jaw was just about on the floor.

Re:Duplicate (from the 19th century) (1)

AtomicDevice (926814) | about 3 years ago | (#37570178)

Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

Please, I think we all know that they mixed peanut butter with chocolate.

Re:Duplicate (from the 19th century) (1)

Abstrackt (609015) | about 3 years ago | (#37570546)

Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

Please, I think we all know that they mixed peanut butter with chocolate.

I'm thoroughly convinced they just mixed sugar with both.

Re:Duplicate (from the 19th century) (0)

Anonymous Coward | about 3 years ago | (#37570660)

Seems to me like saying a Reese's Peanut Butter Cup is a new discovery because they mixed chocolate with peanut butter.

Please, I think we all know that they mixed peanut butter with chocolate.

They didn't MIX pb & choc. The two remain discrete! Sheesh!

BTW: In the snack manufacturing world, they call foods like the Reese's cup "enrobed," so when you eat the chocolate first, you're disrobing it. Sweet!

Re:Duplicate (1)

MagusSlurpy (592575) | about 3 years ago | (#37571090)

No, one of Nocera's previous papers was posted [slashdot.org] , not the one published yesterday. This one is a lot more in-depth synthetically and has much stronger characterization and shows that it actually works as a full system - the earlier paper was just a communication saying, "Look, we did this first!"

Any minute now... (2)

ackthpt (218170) | about 3 years ago | (#37569196)

OPEC assassins will strike and this will be nothing more than a small pile of mysterious rubble and ash in Cambridge, Massachusetts.

Re:Any minute now... (1)

cobrausn (1915176) | about 3 years ago | (#37569256)

The world of Syndicate doesn't happen until 2069, so calm down.

Re:Any minute now... (1)

mevets (322601) | about 3 years ago | (#37569262)

I think you mean Texans....

Re:Any minute now... (0)

Anonymous Coward | about 3 years ago | (#37569396)

Nope. [wsj.com] Try Again. [energyrefuge.com] Oil is just an (admittedly large) part of the overall picture.

Re:Any minute now... (1)

Dyinobal (1427207) | about 3 years ago | (#37569504)

No most people in Texas don't have anything to do with oil. Some of us do work for the oil companies but we don't have any love of them.

Re:Any minute now... (1)

cream wobbly (1102689) | about 3 years ago | (#37571016)

Besides, some Texans who do work for the oil companies are pushing stuff like biofuels from algae greenhouses. I wait with bated breath to see if they can create fuels straight to the pump from genetically modified algae, i.e. no refinement necessary, and I wait with whispring humblenesse to see if they make it to market without disappearing somewhere in the English Channel.

Texas H2 Coalition (1)

perpenso (1613749) | about 3 years ago | (#37569568)

I think you mean Texans....

Yes because texans have no interest in hydrogen production and distribution ... oh wait ... http://www.texash2coalition.com/ [texash2coalition.com]

Re:Texas H2 Coalition (0)

Anonymous Coward | about 3 years ago | (#37570928)

You're ruining his trolling! Stop it!

Re:Any minute now... (1, Flamebait)

Archangel Michael (180766) | about 3 years ago | (#37569338)

No Worries for the Greens, The government will give a couple billion dollars to prop up yet another failing "solar" company that cannot make it without a handout.

People who act like the (R) are better than the (D) and visa versa are just fooling themselves and or worse, useful idiots.

Re:Any minute now... (2, Insightful)

fnj (64210) | about 3 years ago | (#37569424)

Yes; the (R) and (D) for the most part is just a big conspiracy to block any meaningful change. Of course you only mentioned one "side" which is no better than the other. In truth both "sides" are evil.

The real battle is between the establishment and the outsiders - people who actually have independent critical thought.

Re:Any minute now... (2)

DanTheStone (1212500) | about 3 years ago | (#37569660)

Of course you only mentioned one "side" which is no better than the other.

Someone does not understand the meaning of "vice versa" (even if he did spell it wrong).

Re:Any minute now... (1)

greenmanfalling (1866244) | about 3 years ago | (#37570378)

I think "one side which is no better than the other" is what was mentioned. Referring to the fact that the visa-versa inverts the good and the evil without allowing for the possibility of a disequilibrium of good and evil. Of course people that classify others as "good" or "evil" are evil. Also "visa-versa" is correct in espanol. But seriously, be a little less condescending. I'm a banana.

Re:Any minute now... (2)

ewieling (90662) | about 3 years ago | (#37570656)

It seems to me (R) generally want to deregulate business and regulate our personal lives. The (D) generally want to regulate business and deregulate our personal lives. This is the real difference.

Re:Any minute now... (1)

russotto (537200) | about 3 years ago | (#37570816)

It seems to me (R) generally want to deregulate business and regulate our personal lives. The (D) generally want to regulate business and deregulate our personal lives. This is the real difference.

Those are just the talking points. The (D)s want to regulate your personal life, they just use environmentalism, egalitarianism, and "compassion" as their excuses, rather than religion and traditional morality. The (R)s want to regulate business to pick the winners.

Re:Any minute now... (2)

ColdWetDog (752185) | about 3 years ago | (#37569678)

No Worries for the Greens, The government will give a couple billion dollars to prop up yet another failing "solar" company that cannot make it without a handout.

As opposed to the trillions of dollars in 'handouts' to Saudi Arabia and the rest of the Middle East to keep the oil flowing? Or did you think we like to support backwards misogynist despots because they're just like us? (A reasonable supposition, I suppose).

Re:Any minute now... (0)

Anonymous Coward | about 3 years ago | (#37570046)

Yes, yes, the D and R parties are identical. That's why the presidential candidates on the D side are all whackjob born-again Evangelical Christians and zero-tax millionaires.

Oh, wait...

Re:Any minute now... (2)

flaming error (1041742) | about 3 years ago | (#37570214)

The government props up the oil industry, too. And judging from their profits, they most decidedly could make it without the handout.

So it's not clear to me that money diverted to green energy is any worse spent than money diverted to black gold.

Re:Any minute now... (2)

elrous0 (869638) | about 3 years ago | (#37569636)

No, they'll just wait and see if it's even practical to manufacture large scale. If it is, they'll either swoop in and buy up all the companies/patents involved or have their government lapdogs in Congress bury it under volumes of obstructive laws and regulations (you see they DO believe in govt regulation, just as long as it effects competitors but not themselves).

Re:Any minute now... (0)

Anonymous Coward | about 3 years ago | (#37570304)

Don't worry. They won't start marketting it until they can charge OPEC prices. ;)

Re:Any minute now... (1)

DigiShaman (671371) | about 3 years ago | (#37570390)

If they're really concerned about this, they should torrent out the research and other documentation. I'm not worried though. Even if the whole thing were to "disappear" over night, at least people know it's now possible to do. That in of itself is a motivator to re-invent the stuff knowing it has been done before.

News (1)

what2123 (1116571) | about 3 years ago | (#37569230)

Perhaps some of these New Submitter's need to do some look-ups before trying to post new information, AKA News.

Losing Hydrogen (4, Funny)

jameskojiro (705701) | about 3 years ago | (#37569274)

I think all this hydrogen tech is very dangerous, we will start burning hydrogen and more of it will leak and escape from the earth since it is so light and before too long we will run out of water. Oh we will have plenty of oxygen, but the oceans will dry up and all life will die except the giant sandworms... At least we will have spice.

Re:Losing Hydrogen (1)

PeterM from Berkeley (15510) | about 3 years ago | (#37569350)

I wonder how much of a risk this REALLY is. Would human use of H2 and the resulting loss to space from leaks even outweigh the influx of H2 from accretion? Of what leaks, what makes it into space?

And don't worry, so long as you take care of your stillsuit, it will take care of you.

--PM

Re:Losing Hydrogen (1)

fnj (64210) | about 3 years ago | (#37569452)

I assume you're joking. Do you have any idea of the amount of energy locked up in surface water in the form of hydrogen-water bonds? Compared to annual energy usage by humans, times, say, one million?

Re:Losing Hydrogen (1)

PeterM from Berkeley (15510) | about 3 years ago | (#37569540)

Not joking. This is obviously not a short-term problem, I'm wondering just how long-term of a problem it really is, and if any possible human-caused additional leakage could ever be significant compared to the natural loss rate.

I.e., does it take only a million years for the effects to be noticeable, or does it take 10 billion? If it's less than the expected habitable lifetime of the planet, then it's an interesting question.

--PM

Re:Losing Hydrogen (1)

h4rr4r (612664) | about 3 years ago | (#37569930)

The sun will be dead before it matters.

Re:Losing Hydrogen (1)

N!k0N (883435) | about 3 years ago | (#37570036)

before we start with destroying the oceans... I will require the following:
1. A Fremen-made stillsuit
2. Spice

Re:Losing Hydrogen (0)

Anonymous Coward | about 3 years ago | (#37570618)

The expected habitable lifetime is roughly 500 million years. After 1 billion years, the sun will be bright enough that liquid water is no longer present. http://en.wikipedia.org/wiki/Sun#Life_cycle

Re:Losing Hydrogen (3, Informative)

wagnerrp (1305589) | about 3 years ago | (#37570120)

Hydrogen is reactive. It will react with something on the way up through the atmosphere, that makes it sufficiently heavy to stick around. The problem with helium is that it is inert. It's perfectly content on its own, so it will simply float to the top of the atmosphere and exist in trace densities not economical to capture.

Re:Losing Hydrogen (1)

Bob the Super Hamste (1152367) | about 3 years ago | (#37570796)

This is true, unfortunately there is another highly reactive oxidizer [wikipedia.org] very high up in the atmosphere that any escaping hydrogen will react with so I wouldn't be too worried about it leaving the planet entirely, but we might have other problems.

Re:Losing Hydrogen (3, Funny)

istartedi (132515) | about 3 years ago | (#37570950)

OMG! You're right. It'll react and form hydrogon peroxide. This will mix with rain water and get in people's hair. We'll turn blonde, which means we'll start making stupid dec.... Oh no. It's too late, it's started already. RUN!!!

Re:Losing Hydrogen (0)

Anonymous Coward | about 3 years ago | (#37570958)

I assume OP was joking, but let's do some quick back-of-the-envelope calculations just for fun:

World energy consumption is ~474e18 J/year
Energy of formation of water vapor is ~240 kJ/mole (this is how you get energy out of hydrogen fuel cells)
So we need to create ~2 x10e15 moles H20/year
2x10e15 moles = 36 x10e15 g H20 = 36x10e15 cm^3 H20 = 36 km^3 H2O/year
Water covers 36e7 km^2 of the Earth's surface, so each year we would need a layer 1e(-7) km = 0.1mm thick.

So, if we harvested enough H2 to provide the world's energy supply for a year and then just decided to vent all the hydrogen into space, we'd lose a layer of water 0.1mm thick. Of course in practice what actually happens with a fuel cell is that the H2 and O2 are recombined to form H2O once again, and just leaves as water vapor. The only H2 that would be released would be accidental--either because you can't capture all of it when it's being created or some industrial accident spills a bunch of H2.

Re:Losing Hydrogen (1)

ickleberry (864871) | about 3 years ago | (#37569600)

When you burn the hydrogen it becomes water again.

Re:Losing Hydrogen (2)

Baloroth (2370816) | about 3 years ago | (#37569936)

Yeah, and it also makes a giant *WHOOOOSH* when it does so.

Re:Losing Hydrogen (1)

sourcerror (1718066) | about 3 years ago | (#37569674)

Don't worry, we will put our cities under gigantic glass domes.

Re:Losing Hydrogen (1)

GameboyRMH (1153867) | about 3 years ago | (#37569880)

Well this tech could be used in a stationary power plant. Just pure dihydrogen monoxide comes back out, it's just a very complicated form of solar power.

Which means it will probably be less efficient than PV or solar-thermal :-(

If it's a lot cheaper it could still be useful.

Re:Losing Hydrogen (1)

cachimaster (127194) | about 3 years ago | (#37570766)

I think all this hydrogen tech is very dangerous, we will start burning hydrogen and more of it will leak and escape from the earth since it is so light and before too long we will run out of water. Oh we will have plenty of oxygen, but the oceans will dry up and all life will die except the giant sandworms... At least we will have spice.

If you burn hydrogen you get water vapor, it's not lost at all.

Re:Losing Hydrogen (1)

Joce640k (829181) | about 3 years ago | (#37570904)

I think all this hydrogen tech is very dangerous, we will start burning hydrogen and more of it will leak and escape from the earth since it is so light and before too long we will run out of water.

With rising oceans this might turn out to be a good thing...

Re:Losing Hydrogen (0)

Anonymous Coward | about 3 years ago | (#37570932)

soo-soo-sook!

Oh boy (2, Funny)

JustAnotherIdiot (1980292) | about 3 years ago | (#37569282)

The energy crisis is solved for the 6th or 7th time this year.

Re:Oh boy (1)

jovius (974690) | about 3 years ago | (#37569510)

It seems that there's a whole lot of great development and innovation happening in the field.

Now do it for CO2 (1)

Fishbulb (32296) | about 3 years ago | (#37569384)

Now they just need to do that with CO2. Release the O2 [yale.edu] and sequester the carbon to make graphite, graphene, and/or diamond [wired.com] .

Re:Now do it for CO2 (1)

gauntletguy (923413) | about 3 years ago | (#37569418)

Or just make food, like plants

Better fit for artificial leaf epithet (1)

perpenso (1613749) | about 3 years ago | (#37569518)

Now they just need to do that with CO2. Release the O2 [yale.edu] and sequester the carbon to make graphite, graphene, and/or diamond [wired.com] .

The artificial leaf epithet would seem to be a better fit for binding up carbon and producing O2.

Re:Now do it for CO2 (3, Informative)

Attila Dimedici (1036002) | about 3 years ago | (#37569626)

Actually, you bring up a decent point. Hydrogen is not very energy dense. This system would be great if we had a practical fusion reactor, but we don't. A much superior system would be one which takes sunlight, CO2 and water and produces a complex hydrocarbon that could then be used as fuel.

Re:Now do it for CO2 (1)

Dr_Barnowl (709838) | about 3 years ago | (#37569980)

It's called "plants".

Re:Now do it for CO2 (2)

h4rr4r (612664) | about 3 years ago | (#37569984)

Once you have hydrogen and a source of CO/CO2 like a coal power plant you can make whatever hydrocarbons you want.

Re:Now do it for CO2 (1)

Attila Dimedici (1036002) | about 3 years ago | (#37570314)

I was thinking along the lines of something that gets the energy to do this from sunlight. Actually, there are things which do so and are being used to create biofuel. It would just be nice if we could stick something like these "leaves" in a water and CO2 bath in the sun and get complex hydrocarbons. On the other hand, the methods they have for doing that already are actually pretty good.

Re:Now do it for CO2 (0)

Anonymous Coward | about 3 years ago | (#37569996)

Three words: water gas shift [wikipedia.org] . Once you have the hydrogen, it's "relatively" simple to run the reaction in reverse to reduce the carbon dioxide. Add enough hydrogen, and you can reduce the carbon monoxide further to things like methanol and other hydrocarbons (see syngas [wikipedia.org] ). It's not done currently because the largest and cheapest source of hydrogen is running the reactions in the "forward" direction to convert hydrocarbons into carbon dioxide and hydrogen, but if there's a cheap and easy source of hydrogen, reversing it becomes reasonable.

The only complication is then having a reliable stream of pure carbon dioxide to feed into the process, but current carbon capture and storage and carbon recapture strategies might be of use.

Clean water? (3, Interesting)

Anonymous Coward | about 3 years ago | (#37569422)

So, dirty water and sunlight go in, hydrogen and oxygen go out.

Then the hydrogen and oxygen go into a fuel cell, and electricity and pure water come out.

Efficiency isn't anywhere near perfect, but the benefits to a cycle that turns sunlight and dirty water into electricity and pure water are pretty obvious.

Re:Clean water? (1)

Sqr(twg) (2126054) | about 3 years ago | (#37570300)

Yes, it is like a solar still [wikipedia.org] only much, much, more expensive.

Re:Clean water? (2)

Crudely_Indecent (739699) | about 3 years ago | (#37570636)

Oh yeah, because solar stills produce hydrogen and oxygen as well as water by utilizing electricity.

The only thing they have in common is that they use the sun (although, in very different ways). The artificial leaf doesn't produce water, at all. Clean water is a byproduct of utilizing the hydrogen as a fuel (as is heat).

Nothing like a solar still.

Although we don't know a price on these devices, they are made from non-exotic (read common) materials. Even if they cost more than pocket change, the longer they are in operation the more power they produce, only requiring water. Eventually, the value of the power produced will exceed the cost of the device.

Re:Clean water? (1)

Sqr(twg) (2126054) | about 3 years ago | (#37570962)

But we do know the price of these things. Or at least we have a lower bound. They are ordinary silicon-based solar cells, covered with catalysts on both sides. So they cost at least as much as solar cells (per square meter) or at least four times as much (per Watt).

If the only advantage over ordinary solar cells is that you are also purifying water, then it is not worth the extra cost.

Yeah, right. (1)

Sqr(twg) (2126054) | about 3 years ago | (#37569522)

From the article: "The new device is not yet ready for commercial production, since systems to collect, store and use the gases remain to be developed."

Yeah, right. This would be in commercial production right now, if only there were compressors and hydrogen tanks.

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

Re:Yeah, right. (1)

ColdWetDog (752185) | about 3 years ago | (#37569760)

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

Physical efficiency may not be a big deal here. If you are using inexpensive materials and can get the device built reasonably cheaply and it has long term stability (several largish engineering 'ifs' here) then overall energy conversion rates aren't too critical. There is lots of sunlight and lots of water so you can trade off efficiency for square footage (to some degree, it can't be terribly bad at conversion).

The devil will be in the details and as TFA states, there is a lot of engineering work to be done.

Should be ready about the time that holographic storage comes on line.

Re:Yeah, right. (1)

Sqr(twg) (2126054) | about 3 years ago | (#37570028)

My point is this: solar cells made out of the same "inexpensive" materials are barely competitive at 10 % efficiency. Adding catalysts to the sides drops efficiency down to 2.5 %, meaning that you pay four times as much for the same installed power (assuming that the catalysts themselves cost no more than the electric conductors that they replace).

There's no way this is *ever* going to be a good idea, as it can never compete with the same solar cell without the catalyst coatings.

Re:Yeah, right. (1)

Nom du Keyboard (633989) | about 3 years ago | (#37569830)

The reason why this is not in production is obvious. The energy capturing efficiency (and hence cost effectiveness) of the solar cell is reduced by 75 %. (Then another 50 % will be lost if the hydrogen is converted back to electricity.)

Hey, it's not like this process is in competition with some more efficient process for that sunbeam. This device would be capturing otherwise unharvested sunlight, so it's closest competition is producing Zero energy in comparison.

Perfect solution for lumpy power sources. (1)

Anonymous Coward | about 3 years ago | (#37569582)

Things like wind and solar that have extreme peaks and valleys in their generation curve could use this (or any other means of hydrolysis) to produce a steady 24/7 stream of power. They simply need to run a small electrolysis plant and a gas compressor on the supply side, And then burn the hydrogen to run a steam turbine/generator. Yes, there is some loss of efficiency in doing it, but so what? It gives you a 24/7 smooth continuous supply.

Re:Perfect solution for lumpy power sources. (1)

GameboyRMH (1153867) | about 3 years ago | (#37569928)

Or use flywheel storage, or a water reservoir, or a battery...there are many simpler forms of energy storage.

Re:Perfect solution for lumpy power sources. (0)

Anonymous Coward | about 3 years ago | (#37570880)

flywheel storage - loss through friction, loss over time not static
compressed air - need large storage areas leakage if using natural caves
molten salt - loss of energy over time limited efficiency if not already working from a thermal source
water reservoirs - limited availability of paired reservoirs on hills
batteries - loss over time limited cycling times, require expensive metals in substrate, efficiency
ultra-capacitors - not yet manufacturable at reasonable scale for grid sized storage
split water - bulky with some initial loss and a risk of explosion (if improperly handled)
hydrocarbon - risk of explosion (if improperly handled) hard to make (if easy to use)

If thy can split it well enough with the new cobalt catalyst it may be simpler and more efficient than batteries, aside from being cheaper, but you will need lots of armour on those storage tanks. on the other hand it would work for seasonal storage lengths.

Re:Perfect solution for lumpy power sources. (1)

Pinky's Brain (1158667) | about 3 years ago | (#37570886)

Flywheel and batteries are expensive and resource intensive, water reservoirs capable of holding significant amounts of energy (ie. hydroelectric dams) are of limited availability.

Re:Perfect solution for lumpy power sources. (1)

GameboyRMH (1153867) | about 3 years ago | (#37570914)

Flywheels are resource intensive?

Idea (0)

Anonymous Coward | about 3 years ago | (#37569596)

Use these to separate hydrogen and oxygen in a covered, transparent tank, let the off-gas float up a large hill through tubes, burn/redox the hydrogen for power generation, cool the exhaust, store the water at the top of the hill, let it return to the bottom of the hill at night to smooth out energy production...

Re:Idea (1)

benjamindees (441808) | about 3 years ago | (#37570860)

In case it isn't obvious, this idea has a problem with scale. As in, it would take several square miles of these cells to make enough water to run even the smallest hydroelectric generator for a single night, and the power produced would be such a tiny fraction as to make doing so completely pointless.

The Real Question (1)

Xarin (320264) | about 3 years ago | (#37569704)

What I would like to know is if this device can produces net energy over its lifetime after the total energy to produce and maintain it is taken into account. If there is a net loss then it is in effect just a battery for storing energy with less then 100% efficiency.

Re:The Real Question (1)

NeutronCowboy (896098) | about 3 years ago | (#37570530)

Umm, I hate to break it to you, but all devices use more energy than they produce. The reason that oil and gas is so effective for us is that they are the result of a few million years of energy conversion, and we just leverage the equivalent of a battery that has been charged for a few million years.

The only question that matters is whether the energy is easily storable, produces a useful amount of energy and does not result in unmanageable pollution problems.

Back in High School (1)

Nom du Keyboard (633989) | about 3 years ago | (#37569766)

Back in high school I used to do this with a beaker of H2O, a bit of acid to improve conductivity, a battery, and a couple of wires. Nice to know that in the succeeding 40 years or so they've improved the process so greatly by replacing the battery with a solar cell.

Re:Back in High School (2)

Bengie (1121981) | about 3 years ago | (#37570056)

The real question is if it is more efficient than just charging a better with a solar panel. Since that Hydrogen is just a storage medium for "energy".

Re:Back in High School (1)

maliqua (1316471) | about 3 years ago | (#37570470)

Batteries are filled with toxic chemicals and the manufacturing process is even worse. disposal is expensive and dangerous, and often neglected so all that tasty toxicity gets dumped in a land fill.

Re:Back in High School (1)

benjamindees (441808) | about 3 years ago | (#37570884)

It's not more efficient and it doesn't matter. The point is that by integrating the process, perhaps it can be made more cheaply. Cost is all that matters.

Re:Back in High School (4, Informative)

Dr_Barnowl (709838) | about 3 years ago | (#37570082)

The innovative bit is the cobalt catalyst. A lot of other designs use toxic electrolytes (as you mention) or expensive rare metal catalysts. This one has the advantage that all the raw materials are relatively cheap, for a solar panel design - no expensive platinum, gadolinium, etc.

Re:Back in High School (0)

Anonymous Coward | about 3 years ago | (#37570732)

"toxic electrolytes"

But that's what plants crave!

Re:Back in High School (1)

MarkRose (820682) | about 3 years ago | (#37570866)

Don't forget that cobalt is also toxic [wikipedia.org] : ingesting 20 grams or so will likely kill you.

So are lightbulbs (1)

phorm (591458) | about 3 years ago | (#37570980)

There are plenty of things in the world that contains materials that can kill you if ingested in any significant amount.
Thermometers, various lightbulbs, etc.

The question is: how easily is somebody exposed to said materials for ingestion, and will you be easily exposed to it by other methods (inhalation, touch, etc).

We FINALLY know what robot diets will consist of!! (1)

daboochmeister (914039) | about 3 years ago | (#37569888)

This answers it once and for all, robots will be vegetarians!

Reposting every few months (1)

Med-trump (2195662) | about 3 years ago | (#37570136)

This story is running over and over for quite some time. Each instance it is publicized as a new story. I have seen in in the past year at least two other times.

Is this novel? (1)

AtomicDevice (926814) | about 3 years ago | (#37570196)

In what way is this different that replacing the D-cell on my 4th grade science project with a solar cell?

PS.
Fun science project that one was

Re:Is this novel? (2)

nomel (244635) | about 3 years ago | (#37570658)

Having a non corroding electrode, not requiring lots of electrolytes, and doing it all with cheap materials, is what makes it very interesting.

This is an interesting electrolysis problem more than a "power something with a solar cell" problem.

Oh Great, another way to go Boom (1)

NReitzel (77941) | about 3 years ago | (#37570358)

Put it in sunlight and it gives off hydrogen and oxygen, in stoichiometric ratio, from the two sides.

So, if you take this thing and put it in a two-gallon zip bag with a cup of water, in a short time, you have a bomb.

Hydrogen-Oxygen explosions are no joke. This invention sounds like a way for someone to get hurt, by accident. Presumably one would like to have the fuel and oxidizer come off in disjoint, non-connected spaces.

Disclaimer: Note that any descriptions of hypothetical events are metaphorical in nature, and do not intend to portend, suggest, incite, or reflect any overt act, present or future, whatsoever.

Bad for the environment (0)

Anonymous Coward | about 3 years ago | (#37570428)

Water vapor is the number 1 green house gas, far exceeding CO2. So, as we move to these "clean" energy sources we are in fact moving toward a much greater green house effect. What are the alternatives? You can use Boron which has a much higher energy density, is safe to transport, and when burnt forms a powder that you can take with you. The result is that when you burn your fuel, your vehicle's fuel tank will end up being heavier!

Hyde was right. (0)

Anonymous Coward | about 3 years ago | (#37570634)

...And it runs on WATER, man!

Photosynthesis has a bit head start (1)

worldsayshi (1660435) | about 3 years ago | (#37570674)

Not to be a technology pessimist but how is this better than natural photosynthesis? Can we realistically hope to achieve better efficiency in storing energy in carbon based structures than with the technique that nature provides us? Well, maybe in a reeealy long perspective. We will probably have synthesised life a couple of times in different forms before then.

Sounds like very inefficient water electrolysis (1)

Timmy D Programmer (704067) | about 3 years ago | (#37570810)

Sounds like a plain old Solar Cell, rather than deliver it's power via wire to a water electrolysis unit, the electrolysis occurs at the location of the cell??
So.....

The solar cel now needs to be in water and then you have to capture the hydrogen, while trying not to cover up or submerge the cel?

Silly.

Efficiency? (1)

Anonymous Coward | about 3 years ago | (#37570920)

TFA says that the efficiency is under 5% for the 'wired' version and something like 2.5% for the 'unwired'. That's 10x less efficient than electricity-producing solar cells that manage about 25%. But if these have to be submerged in water, we might assume that a good amount of sunlight would be reflected away before it reaches the cell - so maybe the numbers are even worse.

But if you actually need the hydrogen, then you'd have to compare it to a 25%-efficient solar cell plus a 50%-efficient electrolysis unit. So this system is at least 5x less efficient than just sticking some solar panels up and using the electricity to split the water molecules.

The question then is price.

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