Scientists Achieve Perfect Efficiency For Water-Splitting Half-Reaction (phys.org)

Dthief writes: Splitting water is a two-step process, and in a new study, researchers have performed one of these steps (reduction) with 100% efficiency. The results shatter the previous record of 60% for hydrogen production with visible light, and emphasize that future research should focus on the other step (oxidation) in order to realize practical overall water splitting. The main application of splitting water into its components of oxygen and hydrogen is that the hydrogen can then be used to deliver energy to fuel cells for powering vehicles and electronic devices. The process involves exposing the water to a mass of platinum-tipped nanorods, with visible light driving the reaction. The 100% efficiency refers to the photon-to-hydrogen conversion efficiency, and it means that virtually all of the photons that reach the photocatalyst generate an electron, and every two electrons produce one H2 molecule. At 100% yield, the half-reaction produces about 100 H2 molecules per second (or one every 10 milliseconds) on each nanorod, and a typical sample contains about 600 trillion nanorods.

Comments

Oh well.

[sims 2]

Too bad there aren't any uses for oxygen.

Re:Oh well.

[Anonymous Coward]

Too bad there aren't any uses for oxygen.

the cheapest way to store the oxygen so you can use it later is to not store it, releasing it into the atmosphere, and later just use "air" for the reaction. :-)

Re:Oh well.

[skullybox]

Just set the date to Jan 1 1970

Re:Oh well.

[MightyMartian]

I'm not sure I'd want to hang out near the exhaust pipe of such an engine. O2 is rather explosive.

Re:Oh well.

[ShanghaiBill]

the cheapest way to store the oxygen so you can use it later is to not store it, releasing it into the atmosphere, and later just use "air" for the reaction. :-)

Not when you consider the total cost. Air is about 78% Nitrogen, which leads to a lot of inefficiency. Most engines will run much more efficiently with straight O2, or even O2 and some other substance such as injected water. Coal burning power plants that do carbon sequestration use air stripped of N2 so they don't have to separate the CO2 from the N2 in the exhaust. Nitrogen in a combustion chamber also leads to a lot of nasty pollutants that are difficult and expensive to remove. If you are producing pure O2, just venting it into the air is a big waste.

Re:Oh well.

[Anonymous Coward]

I'm not sure I'd want to hang out near the exhaust pipe of such an engine. O2 is rather explosive.

No... O2 is not explosive. It is an oxidizer. It requires a fuel to burn.

Re:Oh well.

[someone1234]

Like... your nostrils?

Re:Oh well.

[dbIII]

Nitrogen in a combustion chamber also leads to a lot of nasty pollutants that are difficult and expensive to remove

Not that hard just add water and pipe it away as very weak nitric acid which is pretty well how "scrubbers" work.
At a power station where I did some work the new manager decided he wanted nice white smoke coming out of the stack for PR reasons. So somebody played with the settings on the scrubber injecting a lot of water into the exhaust which came out as nice white steam. That night was very still, the water condensed out of the air and the utility had to pay for repainting thousands of cars in the city that had nitric acid damaging the paintwork.

Re:Oh well.

[michelcolman]

If you lived on Titan, you might see things the other way around.

Re:Oh well.

[Jesus_666]

Whether using pure O2 in an engine make sense depends on where the engine is used. For a fixed installation it could make sense to use pure oxygen but for something like a vehicle I'd recommend against it - unless you think that vehicle accidents need to become more spectacular.

I do agree, though, that it makes more sense to store the O2 than to vent it. There are plenty of uses for bottles of pure O2.

Re:Oh well.

[Anonymous Coward]

You're a waste of oxygen you winkie-face making moron.

Re:Oh well.

[zAPPzAPP]

The engine is the oxidation part. It outputs water, not O2.

The process described in the arcticle would happen in an industrial complex of some sort.

Re:Oh well.

[TapeCutter]

The energy stored in the hydrogen is released by recombining it with the oxygen to create water which can then be re-split using sunlight. It's a closed loop, that is driven by sunlight.

Re:Oh well.

[Anonymous Coward]

Dude, we can ship it to Mars and the Moon.

Re:Oh well.

[Anonymous Coward]

Whether using pure O2 in an engine make sense depends on where the engine is used. For a fixed installation it could make sense to use pure oxygen[...]

Simple solution. Put the plant that produces the H2 near a plant that burns coal, and use the O2 to fuel its fire. Also, use the electricity from the coal plant to run the H2 production. Makes a nice coal-to-h2 transformer. Turning the evil coal into a carbon-neutral H2 fuel. Until someone notices...

Re:Oh well.

[tburkhol]

The engine is the oxidation part. It outputs water, not O2.

I don't think so. The reduction half reaction they're talking about is
2 H+ + 2 e- -->H2
It has to be paired with and oxidation half-reaction. In this case:
H2O --> O2 + 4 H+ + 4 e-
The whole reaction provides H2 and O2 that can be used in a completely different reaction to drive fuel cell or heat engine.

Re:Oh well.

[Megane]

The question is more whether this O2 is better to keep around than the O2 that is a by-product of making liquid nitrogen. And that O2 starts out as a liquid, so it is much easier to keep pure until it can be put into canisters.

Re:Oh well.

[Tighe_L]

Problem with using too much oxygen is you need the right about of fuel to go with this. Anyone who has a 2 stroke engine knows this. If you run the carb too lean you will burn up the engine. This can happen with 4 strokes too, but there is usually more to prevent this from happening on them.

Re:Oh well.

[omnichad]

Like H2?

Re:Oh well.

[currently_awake]

Hydrogen is a terrible energy source. The gas has very low energy density (big gas tank), compressing it takes a lot of energy, and it leaks through holding tanks. The money that is being wasted on the hydrogen economy should be directed into broadcast energy or putting power rails into the roads.

Re:Oh well.

[Immerman]

How do you figure that's carbon neutral? You're still converting all that geologically sequestered carbon into CO2.

Just because you're scrubbing it from the exhaust and temporarily storing it somewhere doesn't mean it's not there. So far as I've heard, we've yet to come up with a way to store CO2 in the long term. Pumping it into the ground is only a temporary buffering solution, as it begins to leak out almost immediately. Undersea storage is a bit more effective, but much more expensive, and has a devastating effect on the fragile sea-bottom ecosystem with unknown long-term consequences.

Re:Oh well.

[Immerman]

Well, if we were producing H2 on a scale to replace gasoline as a portable fuel source, then I'd venture a guess that the amount of O2 produced would be several orders of magnitude greater than produced as a byproduct of liquid nitrogen production.

Re: Oh well.

[Anonymous Coward]

Why store or compress it? If we can seperate water fast and efficiently enough then we just store water covert it in the vehicle h2 to the engine fresh o2 to the atmosphere

Re:Oh well.

[thegarbz]

False.

Pure O2 is the only thing which breaks the fire triangle (fires require oxygen, fuel, and ignition sources)

It's oxygen, so that's one corner of the triangle.

It turns almost anything into a fuel and handling it is incredibly difficult because of this. For example pure O2 pipelines have "fuses" put into them which is basically a section of teflon pipe with high pressure water jets directed at it because the metal pipework itself becomes a fuel in the presence of pure O2. Most things which aren't a fuel in normal air burn spectacularly in the presence of concentrated O2. That's the second corner of the triangle.

Also pure O2 is easily ignited by any particles in the O2 stream. There's a separate specification for construction and cleaning of O2 carrying systems on top of the standard pipe spec because of this, as well as special ordering requirements for any equipment used in O2 services. If that isn't bad enough it can spontaneously combustion due to adiabatic compression by something as simple as a valve moving too quickly. That's the final corner of the triangle.

  In industry O2 is handled like an explosive and highly volatile substance. The exception is when it is in stationary containment (i.e. a gas cylinder). In most plants handling pure O2, the pipework has special identification on it to ensure people stay the heck away from it.

Re:Oh well.

[BoogieChile]

Yes, your nostrils also need a fuel to burn.

But seriously, if you have pure O2 coming out of your nostrils, then something is seriously wrong with your respiratory processes and you should probably get back to Area 51 at your earliest convenience.

Re: Oh well.

[Anonymous Coward]

Not quite correct. External combustion engines (boilers) and internal combustion engines (both reciprocating and combustion turbines) utilize different working fluids. In a boiler the working fluid is almost always water. In this case you want to burn the fuel as efficiently as possible so the liberated heat is absorbed as efficiently as possible through a heat exchanger (usually high pressure tubes) to a boil a high pressure liquid into high a pressure vapor (usually liquid water into steam), and most usually in a closed loop. In this case the water/steam loop is your working fluid. Reciprocating engines and combustion turbines both burn fuel to heat air, and the air is your working fluid. Most of the working fluid component in air is nitrogen, which as you pointed out is 79%+/- of the atmosphere. Pure oxygen fed to a boiler would work well, so long as the oxygen didn't also burn up the boiler construction materials. Pure oxygen fed to a car engine or turbine would not deliver near the power output. All of that hot expanding nitrogen in an air breathing engine is the primary working fluid. Without it engines wouldn't be nearly as efficient.
Fuel cells are a totally different animal. There is no thermodynamic working fluid in a fuel cell. Here pure oxygen would be desirable, but costly. Being able to snatch oxygen from the atmosphere with a fuel cell would be desirable for several reasons.

Re:Oh well.

[TheRealLifeboy]

Wait, wait! Mix it with carbon to create a marvellous earth greening gas called CO2! It's hugely beneficial for life on earth!

Re: Oh well.

[NigelTheFrog]

I use pure oxygen all the time. It's piped into every room in the building where I work. I'm surrounded by people who have had minimal to no training on safe handling of pure oxygen. (I'm a physician and work in a hospital. For the record, we have pipeline supplies of nitrous oxide as well, which is a similarly strong oxidizer).

Re: Oh well.

[thegarbz]

Our hospitals have the same. All the staff get mandatory training on the hazards of pure O2. Though the hazards are considerably lower at the low pressure and flows used in hospitals and small labs. Your callousness doesn't change the dangers associated with it.

Does it scale?

[Anonymous Coward]

I make that one ten millionth of a mole of H2 per second. Not exactly going to be making industrial quantities via this method, are we?

Re:Does it scale?

[synaptic]

Your math is right based on the summary but the article says:

"With a stable system and a turnover frequency of 360,000 moles of hydrogen per hour per mole of catalyst, the potential here is real."

Re:Does it scale?

[penguinoid]

Yes, but a mole of hydrogen weighs less than a penny, while a mole of nanorods weighs about as much as you or maybe your car or house.

Re:Does it scale?

[Anonymous Coward]

Umm, the most dense materials on Earth are Osmium and Iridium. One mole of those weighs about 190g, which is 2 orders of magnitude less than you, and 4 orders less than a car.

Re: Does it scale?

[Anonymous Coward]

Speaking of density...
GP said mole of rods, not mole of platinum atoms. It takes more than one atom of platinum to make a rod .: a rod will have a mass of more than 6*10^23 time that of a platinum atom.

Re: Does it scale?

[Anonymous Coward]

Even so, a mole is not defined to be used for things like rods. It's only defined for base units like atoms, molecules, ions.
So if he had said Avogadro's number of rods, he would have been correct, but one mole of rods either is invalid/undefined, or is a mole of whatever molecule the rods are made of (and not the whole rod).

Re: Does it scale?

[Bengie]

A Mole of Moles: What would happen if you were to gather a mole (unit of measurement) of moles (the small furry critter) in one place?
https://what-if.xkcd.com/4/

Re: Does it scale?

[Anonymous Coward]

False, a mole is an Avogadro's number of any unit. One could have a mole of apples, a mole of cars, a mole of atoms or a mole of stars. We are simply used to seeing moles being used in the context of atoms/molecules but it is not limited to very small particles. However, there are very few large objects that there would ever be a mole of them. However, given as the rods are in effect point catalysts/electrodes it makes perfect sense to refer to a mole of them as a mole of them would produce a turnover rate of moles per second. If the turnover rate of the platinum point is 120, then one mole of rods at VMax would produce 60 moles of H2 per second.

Re:Does it scale?

[orpheus]

Your math is right based on the summary but the article says:

"With a stable system and a turnover frequency of 360,000 moles of hydrogen per hour per mole of catalyst, the potential here is real."

Yes, but the specific numbers given would indicate 360,000 MOLECULES/hour, which makes it seem much more likely that the article itself misspoke by saying "moles" where it should have said "molecules"

Sanity check: 360,000 moles/hr per mole of catalyst = 100 moles/sec per mole of catalyst = 6x10^25 reactions/sec per molecule of catalyst.
You can't get a reaction time of 1/(6x10^25) sec = 1.7x10^-26 sec for chemical reactions in our current universe (maybe in a Big Bang)
  1.7x10^-26 sec is FAR less time than it takes a photon to cross the width of a proton (and a proton happens to be an H+ ion)

Is it?

[Anonymous Coward]

Is it too soon to say "Fuck you oil companies." ?

Re:Is it?

[wonkavader]

It's never too early to say that.

"Fuck you, oil companies!"

The article doesn't enable that, or make it any more useful, but it also doesn't make it any less satisfying.

What about energetic yield?

[Atmchicago]

OK, so all the atoms make it into the product, but what's the energetic cost, or yield? Isn't that what really matters? Yes, I could read the article, but that's what a good summary is for -- spelling out the result in a sentence or two.

Re:What about energetic yield?

[jeffb (2.718)]

You, um, need to read the second paragraph of the summary. That 100% DOES refer to quantum efficiency -- they're claiming that essentially every photon that reaches the catalyst frees an atom of hydrogen.

Re:What about energetic yield?

[JoeMerchant]

Activated by photons, you know like a solar cell?

Re:What about energetic yield?

[RoccamOccam]

With a 100% photon-to-electron conversion efficiency? If that is is the case, why are they concerned with the water-splitting?

Re:What about energetic yield?

[JoeMerchant]

Got to capture those electrons in useful form - no good liberating an electron and having it resorbed a few nanoseconds later.

Corroding nanorods

[lannocc]

And the nanorods still corrode, something they say needs to be addressed. I think this takes the practical efficiency below 100%.

Re:Corroding nanorods

[JoeMerchant]

When I see platinum nanorods in water, I worry that anything more than absolutely pure water will leave its "more" deposited on the nanorods, rendering them useless in a big big hurry.

Re:Corroding nanorods

[Anonymous Coward]

Maybe instead of the nanorods being on a flat, linear surface they're floating...i.e. a powder. That'd get you more surface area and the ineffective material should fall out as it's heavier. No idea how much harder an engineering problem that is.

Re:Amazing, hey whipslash

[jenningsthecat]

When are you going to fire this idiot editor, whipslash?

Agitating to get someone fired while sitting in nice, cozy anonymity. Yup, classy behaviour indeed. Asshole.

The thing is

[Dunbal]

and a typical sample contains about 600 trillion nanorods.

That sounds like a lot, but Avogadro's number is still way, way bigger than that. How many decades before this produces 1 mole (2g) of hydrogen gas?

Re:The thing is

[suutar]

about 3.8 months, unless I dropped a decimal. 6e23 atoms wanted / 6e14 rods means we need to generate 1e9 atoms per rod; at 1e-2 seconds per atom per rod, that's 1e7 seconds or 115ish days.

Re:The thing is

[PPH]

Or one could use multiples of "a typical sample".

Re:The thing is

[grimmjeeper]

You forgot to factor in that the sun is only up for half the day (on average). So only 12 hours a day will have usable light. My math rounds out at 231 days per mole. Factor in real world limitations like the effect of weather and I would estimate somewhere in the neighborhood of a year per mole when it's all said and done. I think they're going to need a whole lot of these things to be actually useful.

Still in all, it's a good advancement in the right direction.

Re:The thing is

[Okian Warrior]

about 3.8 months, unless I dropped a decimal. 6e23 atoms wanted / 6e14 rods means we need to generate 1e9 atoms per rod; at 1e-2 seconds per atom per rod, that's 1e7 seconds or 115ish days.

The paper is restricted (paywalled?), but assuming 600 trillion nanostructures, sqrt(600 trillion) is a square about 24 million on a side. The Platinum atomic radius is about 0.13 nanometers, so rods 1 nanometer wide mean that the "typical sample" is 24 million nanometers on a side, or 24 mm on a side.

Assume a typical sample is 1cm (10 mm) on a side, a square meter would be 100cm x 100cm, or 10,000 times more.

Using your figures, 1e7 becomes 1e3 seconds, or about 15 minutes, unless I dropped a decimal or my assumptions are flawed.

One mole of Hydrogen gas per square meter every 15 minutes is still a pretty small yield, considering that you need sunlight on the entire surface.

Re:The thing is

[Ungrounded Lightning]

You forgot to factor in that the sun is only up for half the day (on average). So only 12 hours a day will have usable light.

But then there's cosine error from the light not hitting the surface straight on. (At a solar-farm level it applies even to tracking systems, since you're really interested in the amount of ground surface area involved.)

Then there's things like non-noon light taking a longer path through the admosphere (especially near sunrise and sunset) latitude, weather, season, altitude, near-horizon obstructions, etc.

It all gets combined into a "solar hours" number: That's the equivalent number of hours of noonday sun collected by a panel pointed south and tilted to the latitude - as if the sun appeared at its noontime position, stayed around for that long, and disappeared.

For a usually-cloudless site around the middle latitudes of the middle of the continental us (i.e. northern CA, Nevada's high desert, etc.) figure it averages out over a year to about 5 solar hours per day.

Re:The thing is

[Dunbal]

In which case I will put it to you differently: Hydrogen gas is currently priced around $1/kg = $2/1000 mole = $0.002/mole. Excluding the cost of collecting, compressing and bottling your gas (let's say you can pay for all that with the oxygen you sell - since you also get oxygen) - it will take you 158 years to pay back $1 per "typical sample". I am sure these cost more that $1 to make. Therefore while academically interesting, these are not and will probably never be industrially/economically viable. I don't think "scaling up" will help.

Re:The thing is

[Anonymous Coward]

Isn't there an entire other dimension they could be using to increase surface area?

Re: Amazing, hey whipslash

[Anonymous Coward]

Thats 1x H2 per nanorod. And it says they are sampling with what was it, about 600 trillion nanorods..

what do they mean with two step?

[gl4ss]

the article is confusing. googling for water splitting half reaction results mostly just in this article or copies of it itself.

they can pluck the h2 from the O but the O doesn't want to O2? and it just reacts back to water? so they can make H2 from water with 100% efficiency except that they can't?

in their not-just-water(they mention "high ph") solution? I'm not sure this is big enough news to tout all over the world with a trombone as they seem to be doing.

Re:what do they mean with two step?

[Goetterdaemmerung]

Nowhere does it state Oxygen is produced in the process.

Re:what do they mean with two step?

[U2xhc2hkb3QgU3Vja3M]

Only Jean Michel Jarre can produce Oxygène.

Re:what do they mean with two step?

[kuzb]

That may be true, but only The Orb can produce Toxygene.

Re:what do they mean with two step?

[Anonymous Coward]

...and he produces it with magnetic waves.

Re:what do they mean with two step?

[michelcolman]

They are not splitting water at all. They are just encouraging individual H atoms (H+ ions, or basically protons) to combine into H2 molecules.

Normally, even pure water has a whole lot of individual H+ ions floating around in it, and the same number of OH- ions. Those H+ don't combine into H2 because that would require extra electrons, which are stuck in the OH- ions. That's why you can create H2 using an electric current which delivers the missing electrons so the H can pair up. (This doesn't work very efficiently in pure water, but a bit of catalyst helps a lot.)

Acidic solutions have more H+ (along with negative ions from the acid, like for example HSO4-), basic solutions have less H+ (and more OH-)

Apparently the researchers are using a basic solution (high pH, lots of OH- and less H+), and then using photons to liberate electrons from the OH- to allow H+ to combine into H2.

This works best in a basic solution because the problem is not so much the number of H+, but rather the number of OH- ions that can be persuaded to give up an electron by nudging them with a photon. In an acidic solution, most of the eligible electrons are stuck in the negative ions from the acid which are much more possessive of their electrons.

The big novelty is apparently that they can get the OH- to give electrons to the H+ and let them combine into H2, rather than combining back into H2O.

Re:what do they mean with two step?

[Anonymous Coward]

And only Michael Jackson can produce Billie Jean.

Re:what do they mean with two step?

[Anonymous Coward]

But she's not his lover.

Re:what do they mean with two step?

[dave420]

Well played, sir. :)

Re:what do they mean with two step?

[Megane]

He does it using a Revolutionary process.

Re:what do they mean with two step?

[tburkhol]

Apparently the researchers are using a basic solution (high pH, lots of OH- and less H+), and then using photons to liberate electrons from the OH- to allow H+ to combine into H2.

That would leave you with uncharged hydroxyl radicals with an unpaired electron, so I don't think that's what they're doing. They are only talking about the reduction half reaction (2 H+ + 2e- --> H2). There has to be an oxidation half reaction. You're proposing (OH- --> OH + e-), but they're talking about splitting water, ie : 2 H2O --> O2 + 4 H+ + 4e-

I suspect they need the high pH to let the H2 diffuse away.

Re:what do they mean with two step?

[Anonymous Coward]

Completely stupid summary. Splitting water is a one-step process.

Re:what do they mean with two step?

[TheSouthernDandy]

They're also not splitting water because in order to prevent the hydroxyl radicals (formed from hydroxide ions after taking one electron out) from chewing up everything or taking their electron back (thereby lowering the photonic efficiency), they quench them with isopropanol. So, they have made an isopropanol-fueled photoelectrochemical cell that uses water as an intermediate electron donor. Next.

Still has the problem of night

[blindseer]

This process requires day light to function, therefore it's potential output is limited by the amount of time the sun shines. Not only is there night but also clouds.

I hate solar power, not just because it is so limited but because so many tree hugger types flock to it. The chemistry of this process is very interesting but if used to convert sunlight to hydrogen then I believe this is a waste of time. Solar power is a distraction from energy production schemes that actually work.

Let's take a look at the technology, it requires carbon nano-tubes laced with platinum. Can we think of a material that is even more expensive than that?

I like nuclear power, especially molten salt reactors. To build those it take low tech materials like Portland cement, nickel alloys, steel, graphite, and salts. The fuel is common thorium and uranium, not the rare U-235 but unenriched uranium. We can run a molten salt reactor day and night and build them to produce many megawatts and still be small enough to move by an over the road truck.

If they can use this high tech hydrogen production process and marry it to a nuclear reactor then we might have something. If we have to set it out in the sun and hope for good weather then I'm not interested.

Re:Still has the problem of night

[JoeMerchant]

All it needs are photons, I wonder if Co60 decay photons do anything good for them?

Re: Still has the problem of night

[Anonymous Coward]

Somebody doesn't understand why solar power is used.

Because it is there for the using. Nothing else.

But hey if you hate it so much, stop eating.

Re:Still has the problem of night

[dbIII]

I hate solar power, not just because it is so limited but because so many tree hugger types flock to it.

Just ignore that and think manly thoughts about the Apollo program like the rest of us. It's an engineering thing and not a "tree hugger" thing.

it requires carbon nano-tubes laced with platinum. Can we think of a material that is even more expensive than that?

Since it's on a tiny scale with potentially a vanishingly thin coating I'd say just about everything else, especially since it's just about as corrosion resistant as it comes so will last.

If they can use this high tech hydrogen production process and marry it to a nuclear reactor then we might have something

Photons are photons so why not?

If we have to set it out in the sun and hope for good weather

Large portions of the globe are well known for not being cold, wet and dismal :)

Re: Still has the problem of night

[Anonymous Coward]

That's rather disingenuous. It's absolutely not just there for the using: I had to buy panels, wiring, roofing ... and there's the vexed question of whether the subsidies are a valid use of funds compared to other uses. There's repair, cleaning and other maintenance. Someone had to use nasty materials to make the panels etc.

Unless you mean "the energy input is there for the using" - in which case, if we love systems where the fuel is cheap and we disregard the costs of development, construction and operating, then you've just bought fusion back in. And fission ... and space mirrors. In fact, if you ignore the cost of extraction, refining and transportation, then oil and gas are there for the using too!

Re:Still has the problem of night

[wbr1]

This is not a solar energy 'scheme'. It is a more efficient method to produce hydrogen for fuel cells. I too am a fan of nuclear, properly done, but solar energy and solar processes have their place in a good energy mix.

Re:Still has the problem of night

[K. S. Kyosuke]

I think your best bet at the moment is good old alkaline electrolysis and demand response, preferably with the electrolyzers colocated at large utility-scale PV plants and using direct DC wiring.

Re:Still has the problem of night

[Anonymous Coward]

I don't see why you dislike solar energy so much. I drive an e-Golf that is charged with energy from a PV array on my roof (which is temporarily stored in LiFePO4 batteries).

The system only cost me about $80,000 to implement and I can drive a whole 80 miles at a time between charges. It's fantastic!

Re: Still has the problem of night

[Anonymous Coward]

That's rather disingenuous.

No, it's not. It's right there, overhead, being pumped out by the sun. Simple factual statement, not hard to realize.

It's absolutely not just there for the using: I had to buy panels, wiring, roofing ... and there's the vexed question of whether the subsidies are a valid use of funds compared to other uses. There's repair, cleaning and other maintenance. Someone had to use nasty materials to make the panels etc.

You seem to think this was about specifics of detail, as opposed to the use of solar power. It's right there. Use it or what? Don't use it, and it's still there.

That is why solar power is used. Because it is there. C'mon, it's not hard to grasp. The sun is used, because it's there.

Same reason plants have chlorophyll.

Unless you mean "the energy input is there for the using" - in which case, if we love systems where the fuel is cheap and we disregard the costs of development, construction and operating, then you've just bought fusion back in. And fission ... and space mirrors.

Fusion is powering the sun, as I recall. And space mirrors would also be part of using the sun. Not sure what you're trying to gab about there.

But I'm not aware of any working fusion reactors on Earth, they don't seem to be quite as sustained.

Fission seems popular though, and I believe that the reason thorium keeps getting suggested is due to its own abundance.

In fact, if you ignore the cost of extraction, refining and transportation, then oil and gas are there for the using too!

Yes, that's why they are used. Same with coal.

The thing is, fossil fuels have a limit to their usability that is a good bit shorter than some other options. Especially the sun, it shouldn't run out for billions of years.

Re:Still has the problem of night

[omnichad]

Solar power is a distraction from energy production schemes that actually work.

Solar power is the root of all energy production schemes that actually work. With maybe an exception for nuclear. It's the only energy input into our otherwise closed system. Oil and coal are both sequestered solar power, while wind and hydro are both driven by solar power converted to heat.

Re:Still has the problem of night

[Lab Rat Jason]

This is not an attack, I'm genuinely interested here:

What do you figure is the break-even point between the car + solar + storage + maintenance vs. ICE car + gas + maintenance? Which component do you think will give out first, and when do you think it will give out? I'm interested because I actually have some solar guys coming to the house Saturday to discuss some panels, and I'm curious how you figured the value of the deal. For me it would start by offsetting grid power, but I would love to be able to get into an EV (but a coal powered EV doesn't really appeal to me).

Thanks,

Re:Still has the problem of night

[wwalker]

You are forgetting geothermal, which might be partially nuclear in nature, if I'm not mistaken. Come to think of it, solar power is also nuclear at its root (except fusion, not fission). So it's all nuclear all around.

Re:Still has the problem of night

[omnichad]

OK. Geothermal, yes. But the cause of the energy in solar power isn't really relevant since that in itself is outside the Earth's energy system.

Re:Still has the problem of night

[Anonymous Coward]

And tidal, using the gravity of the moon which lets us extract the energy from its rotation around the Earth, reducing its speed slightly. Non renewable of course, it comes from when it was formed (and possibly asteroid impacts imparting it more speed?).

Re: Amazing, hey whipslash

[Anonymous Coward]

Holy crap. Check out this idiots posting history.

What a Timmy ass kicker.

Wait a minute...

[__aaclcg7560]

How many nimrods does it take to make hydrogen?

Re:Wait a minute...

[Bite The Pillow]

It wouldn't have taken so long if they focused on splitting yo mommas legs instead.

Pow! Chair to the face!

Re:Amazing, hey whipslash

[Anonymous Coward]

Says the person hiding their real name beyond pseudoanonymity.

ExxonMobil president here

[ls671]

Thanks for the tip guys!

There is definitely more energy (hydrogen) in the oceans than there is in those silly oil patches. Who needs water anyway?

We might have to make a deal with Nestlé but this should come along well.

https://www.salon.com/2015/04/...

Truly yours,

Rex Wayne Tillerson

Re:ExxonMobil president here

[Anonymous Coward]

Fracking uses 0.00062% of California's freshwater. Nestle bottled water uses 0.0035%. You're hyperventilating over a non-issue. Source

Re:ExxonMobil president here

[ls671]

Gee... can't you read? I am switching ExxonMobil into an hydrogen producer and the hydrogen will come from water. I have to make a deal with Nestlé because they already have water patented in some part of the globe. Who is talking about fracking and bottled water? Not me...

Here is Nestlé CEO goal and they have some advance on us, hence the required deal between us:

http://www.naturalnews.com/040...

Re:ExxonMobil president here

[Anonymous Coward]

There is definitely more energy (hydrogen) in the oceans than there is in those silly oil patches.

No there isn't. There is energy in light and it can be captured by breaking the bond in water.
And it's this energy that you get back by burning hydrogen to water.

Re:ExxonMobil president here

[ls671]

brilliant! At least somebody knows what she/(he) is talking about in here...

Re:ExxonMobil president here

[TooManyNames]

I'd say that the AC can read rather well... Your implication in referencing that Salon article (really? Salon?) is that Nestlé is a nefarious corporate entity in California, profiting from a water shortage that it is helping to produce. While that may be technically true in the most pedantic sense -- they sell bottled water, some of which comes from California taps which are being depleted -- it's not true in a practical sense as the AC pointed out. Moreover, Nestlé is acting well within their rights -- and the rights of the Native American populations that they've partnered with -- according to state laws that Californians agreed to abide by. While it's fine if Californians want to change those laws, it's bullshit to act as if Nestlé is evil (it may be, but not due to this issue) for conducting business as usual when that business A) isn't as impactful as the article would like to suggest and B) is well within the laws of the land.

Seems that someone just called you out on your bullshit, and deservedly so.

Re:ExxonMobil president here

[ls671]

Wake the fuck up. I am just a professional humorist testing my puns here on /. before the show.

Thanks for your participation.

-Rex Wayne Tillerson

Lets talk about hydrogen

[Anonymous Coward]

Come join the conversation at www.reddit.com/r/htwo

Hydrogen will become very interesting once hydrogen storage containers come down in price due to economy of scale. Anyone with a water hookup and sunlight could run their own hydrogen refueling station.

Re:Lets talk about hydrogen

[DirkDaring]

Or you could just run solar and a battery and not bother will all that junk.

Re:Lets talk about hydrogen

[Ranbot]

Hydrogen will become very interesting once hydrogen storage containers come down in price due to economy of scale. Anyone with a water hookup and sunlight could run their own hydrogen refueling station.

Many things get interesting with economies of scale, but that's putting the cart before the horse. New technologies have to be viable for public/private investment from the outset.

Re:Amazing, hey whipslash

[Anonymous Coward]

When are you going to fire this idiot editor, whipslash?

Agitating to get someone fired while sitting in nice, cozy anonymity. Yup, classy behaviour indeed. Asshole.

Do you have shit for brains, 'jenningsthecat'?

Honestly, you don't seem to understand what anonymity means. Did you get dropped on you head when you were a kid?

OMG, here come the scammers

[NewtonsLaw]

Oh my God... I can hear the "Run your car on water" scammers firing up their computers right now. There's bound to be another wave of crappy scams for sale online which will tout this as the kind of breakthrough that has finally made it practical to boost your mileage by 500% and reduce gas costs by 600%. Just send $49.95 now for the secrets of how this nano-technology can let you split water into hydrogen and run your car for free!

Groan!

Even PT Barnum would roll in his grave!

Re:OMG, here come the scammers

[Anonymous Coward]

It's not the scammers that will make money, it's the researchers that will get another huge grant for a scientifically interesting, yet industrially implausible, research project.

There may be enough fundamental science learned on this one to be worthwhile. I just wish they didn't sell it as a future energy alternative.

Peak Water

[Ailicec]

It's a little early to get worried about it, but when we finally get a hydrogen economy going, I wonder how much water we'll lose due to leaking hydrogen. Billions of devices leaking a little bit over many years would add up. Maybe technology will move on the next step before it's a serious problem.

Re:Peak Water

[Anonymous Coward]

Well, with global warming and all, we can start to reverse the ocean's rise with this wonderful new technology.

Re:Peak Water

[Anonymous Coward]

It will be far from enough. Also, H2 recombines randomly with O2, so the amount of H2 in the atmosphere will be limited to the leaking rate.

Re:Peak Water

[bluefoxlucid]

A hydrogen economy would be useless for exactly that reason. To store hydrogen, you need exotic materials and high-energy cooling systems. Hydrogen leaks through sealed steel; you'd need to use a lot of energy to keep a hydrogen storage unit idle. This is okay when you're making, shipping, burning; but it's not okay when you fill up your gas tank once a month.

If they could combine the hydrogen with CO2 and make O2+C4H, they could use methane to drive fuel cells or internal combustion. You can actually store methane.

Re:Peak Water

[Zeroko]

Some should leak into space before recombining with oxygen. H2 is very light. But yeah, probably not enough to lower the oceans appreciably, given that they cover ~75% of the surface.

The numbers say...

[DrTJ]

100 H2/s/rod * 600 Trillion rods / sample = 6 * 10^16 H2/s/sample

High number, but small compared to Avogadro's number: Na = 6*10^23
I.e. it takes approximately 10^7 s (~117 days) to produce one mole (~1g) of hydrogen gas (per sample).

If you would construct a factory which produces a ton (a bit modest, but still) on H2 every day, you'd need 10^6 grams per day. That leads to 10^6*117 ~ 10^8 samples.

I wonder that a sample costs... and what the price of a ton H2 is currently on the market. Let me make a wild guess of a dollar per sample and a $1000 for a ton on H2. Profit margin of 10% yields a $100 per day. That $10^8 investment would need approximately 10^6 days to reach break even.

Yay, in only 2700 years we can start to make some money!

Care to invest?

Ok, so what does this mean economically?

[jcr]

Hydrogen sells for about $1/Kg today. How much cheaper will it get with this process?

-jcr

Re:Ok, so what does this mean economically?

[Anonymous Coward]

well, you now get 100 units of hydrogen for the same marginal cost as 60 units. Assuming that you buy at cost, and the start up costs for the processes are comparable, a unit of hydrogen now costs 60/100 the price. So hydrogen is on sale now for 40% off ~ ($0.6/Kg if what you say is correct). Also, apparently, the ratio of $0.6 to the cost of electricity (used to split the H2O) is a theoretical minimum.

it isn't as much as it sounds...

[Anonymous Coward]

600 trillion nanorods X 100 H2 molecules/nanorod/sec ... sounds impressive, until one considers that this implies roughly 112 days of operation to generate a sinless mole of H2. we might need to scale this up a bit.

Re:it isn't as much as it sounds...

[belthize]

Would it be faster if the hydrogen didn't covet its neighbor's wife ?

Entropy

[wkwilley2]

Entropy just isn't what it used to be.

Re:Entropy

[belthize]

It's a hell of a lot bigger now than when I was a kid.

Re:Amazing, hey whipslash

[Anonymous Coward]

When are you going to fire this idiot editor, whipslash?

Agitating to get someone fired while sitting in nice, cozy anonymity. Yup, classy behaviour indeed. Asshole.

Do you have shit for brains, 'jenningsthecat'?

Honestly, you don't seem to understand what anonymity means. Did you get dropped on you head when you were a kid?

Why are you insulting shit?

Shit at least can be used as fertilizer.

Useless for vehicles, waste of energy

[DirkDaring]

Elon Musk says it best. "Hydrogen is an incredibly dumb” alternative fuel

http://thinkprogress.org/climate/2015/02/12/3621136/tesla-elon-musk-hydrogen-dumb/

Re:Useless for vehicles, waste of energy

[Anonymous Coward]

Musk was right that it's dumb compared to battery driven cars for the common man, but hydrogen has its niche uses in the automotive industry as well. It's main use however is for chemical processing and there's nothing dumb about that.

Terrible assumption: hydrogen for transportation

[Anonymous Coward]

The main application of splitting water into its components of oxygen and hydrogen is that the hydrogen can then be used to deliver energy to fuel cells for powering vehicles and electronic devices.

No, hydrogen should be created by renewables, stored, and consumed to smooth out the generation peaks inherent to solar and wind.

We already have perfectly good ways of transporting energy (read: electric grid). Hydrogen density is terrible to use for transportation.

Water vapor is a green house gas

[Anonymous Coward]

and a strong one. just sayin...

Hydrogen Combustion is a better than Electric cars

[Tighe_L]

I would take Hydrogen Combustion engine car over a Electric car any day. Electric cars are dumb, batteries are expensive to produce and generate a lot of waste. Hydrogen combustion engines produce water vapor.

decent

[sacrilicious]

Yeah... I guess that's pretty good... but I hope this success doesn't keep scientists from striving for even higher efficiency numbers.

Quantum mechalical Splliting

[aronpatinson]

is there any researches going on quantum mechanical level about this splitting reaction

Re:Hydrogen Combustion is a better than Electric c

[Anonymous Coward]

Hydrogen combustion engines produce nitrogen oxides and waste lots of energy as heat.

Redox

[Immerman]

I wonder...

The dissociation reaction H20 -> OH- + H+ occurs spontaneously in pure water. Combine that with their reduction reaction, and you could potentially produce H2 without further inputs, at least until the OH- concentration built up enough to strangle it.

If using a continuous flow of fresh water instead of a fixed reservoir, you could keep the reaction up indefinitely. Though I suppose the H2 concentration would probably remain low enough to stay fully dissolved in the water. And even if you could pull it out somehow, I would worry about the chemistry occurring downstream with all the OH-.

Attach it to long carbon chains

[edtice1559]

And then pump it into the ground. Use nuclear energy to power the process and we could have net negative carbon emissions!

Re:Hydrogen Combustion is a better than Electric c

[Tighe_L]

Who cares about wasted heat? Electric motors aren't 100% efficient, If you interweave a sterling motor between the cylinders of the combustion engine you can recover some of the lost energy.

Not necessarily about bulk price

[phorm]

It's not just the sale price, but what you can accomplish when this process is doable on-the-fly and/or portable.

Not exactly

[Anonymous Coward]

Most engines would explode under purified O2 since the rate of reaction would go way up (think the hydrogen balloon with and without oxygen that gets lit with a candle at chemistry demonstrations) without the dilution the inert-ish nitrogen creates.

Plus, pure O2 has a nasty habit of turning things that can burn into spontaneous infernos (Apollo I anyone?) should it leak out of a container and collect somewhere, like your trunk. Combined with the normal vibrations of a car and that H2 exposure makes EVERYTHING much more brittle you could have some interesting catastrophes.

Even iron burns under the right conditions...

There is also the added fact that using the numbers in TFA (600 trillion catalyst particles at 100 molecules of H2 per second per rod) it would take 319 years to produce a mole (6.02e23 molecules) of hydrogen. Possibly 600 if I counted atoms instead of molecules, and that assumes no hindrance in reaction rate due to oxidation rates being less...

Re:Hydrogen Combustion is a better than Electric c

[Muad'Dave]

Only if you're using air instead of the oxygen you just made when you cracked the water.