Process to Produce Hydrogen from Water Using Sunlight Reaches 16.2% Efficiency, on Its Way to Meeting DOE Target

current ways, indeed.

Jeroen Belleman

I find it amusing when people denigrate basic research because they can't s ee how the invention could be practical. Nearly everything we have today s tarted as a very impractical invention that took a great deal of work to tu rn it into the product or service we see today.

What is natural about polluting the atmosphere without cost? Yes, I guess the term "natural" applies in the same way it applies to "natural" remedies . Sure, rubbing a root on your infection might sound "natural", but applyi ng an antibiotic is a lot more effective.

Rick C.

ote:

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nergy & money.

Wow! Such absolute statements are "always" wrong. We can already scrub CO

2 from the air very economically. It's called "farming". There are many p roperties where they grow trees which suck CO2 from the air to grow turning it into lumber. This lumber is a great by product which is used to build homes where the CO2 is sequestered for many, many years.

Totally positive both economically and environmentally.

Rick C.

To be fair about externalities, we'd have to pay people for donating CO2 to the atmosphere.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

at 400

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No one

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energy & money.

CO2 from the air very economically. It's called "farming". There are many properties where they grow trees which suck CO2 from the air to grow turni ng it into lumber. This lumber is a great by product which is used to buil d homes where the CO2 is sequestered for many, many years.

Trees are not all that efficient, requiring 10,000 acres to neutralize the CO2 emissions of 1MW coal fired electricity production. Then there is the l ittle problem of leaf litter decay and methane production, which the scient ific community is just now realizing is extremely significant. Atmospheric physicists tend to not know much about things like soil microbiome and meth ane production, and have all but ignored it until recently.

[...]

What? You call using a solar cell to generate electricity and use that to electrolyse water on the spot 'basic research'? There is nothing inventive about it. It's just a very inefficient use of solar energy.

Jeroen Belleman

Ok, so you clearly don't understand the invention. Not sure how 16% effici ency is "inefficient" for solar conversion. What numbers would you conside r "efficient"?

Rick C.

How about you explaining to poor stupid me what's so novel about this? Explain their dodgy efficiency numbers too, while you're at it.

Jeroen Belleman

What would be the relative global warming of

A square meter of solar cells, making hydrogen by electrolysis instead of burning ng

or

A square meter of mirror or white plastic reflecting sunlight back into space?

Gotta do the math, I guess. I'm thinking the white stuff would win. It would sure be cheaper.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Well, photovoltaic cells might be common to various schemes, but mounting them in air, connecting in (series? parallel?), converting to battery-charge current, inverting to make AC, is a difficult infrastructure, and doesn't scale well.

Mass-producing nodes that can sit in a bath and outgas a useful product to pipes, is a completely different physical plant, and it DOES scale well. Considered as a civil engineering challenge, the light-to-hydrogen-to-storage scheme can be low-cost, robust, and economically efficient. Why would 'dodgy' thermodynamic-efficiency numbers be a problem?

We build according to economic efficiency (a different number entirely).

The 'mirror or white plastic' doesn't couple sunlight input to heat, but it also doesn't couple heat to thermal radiation output. So, it has no net heatflow effect, it just insulates a bit of ground.

Even if it DID do the warming thing, acidifying oceans would still be a byproduct of CO2 pollution, and you'd have to maintain a square meter of random stuff (clean, repaint, detour around it, pay interest on the installation capital cost).

There was a time, decades ago, when people came up with lots of random ideas; conclusive analyses of global warming have a quarter century of age on them, and new, random, ideas just aren't a good use of bandwidth. Try to debug them before posting.

Not really the math that's at fault, you forgot that DAY is followed by NIGHT, and ignored the latter. 'the math' sounds rather off-putting, but mostly people will understand nighttime.

What is dodgy about the numbers? You can't understand why it is novel unti l you understand what they are doing. They didn't take a solar cell and co nnect it to a glass of water.

Rick C.

Why does JL not understand even the most basic of concepts of AGW? He seem s to acknowledge that CO2 does act to raise the global temperature of the p lanet. He must since he keeps talking about how beneficial it is to plants to have more CO2 and higher growing temperatures. So why does he think th e AGW impact of sequestering carbon or at least not releasing more of it is really about the albedo???

Is JL really that stupid?

Rick C.

John Larkin's idea of "fair" reflects what he gets told - and believes, the gullible twit - by his denialist websites.

The information on those web-sites is assembled by people who make a lot of money out of extracting fossil carbon and selling it as fuel, and want to keep on making money that way.

More disinterested observers do the computations differently.

The best estimate is currently about $US 115.0 worth of damage to the envir onment per tonne of carbon burned.

There's a lot of discussion about discount rates for future damage and $US

200.0 per tonne might be closer to the mark.

--
Bill Sloman, Sydney

n

ciency is "inefficient" for solar conversion. What numbers would you consi der "efficient"?

-market/

SunPower cells that convert 22.2% of the energy in the incident solar radia tion are the most efficient you seem to be able to buy. Single junction cel ls seem to have theoretical upper limit of 33.16%, and multi-junction cells of 86.8%.

People have made two-junction solar cells and got to 44.4% efficiency in ve ry expensive cells, which need concentrated sunlight to be worth using.

The catch with using hydrogen gas to store the energy captured is that you can only recover 26% of the energy expended generating the hydrogen - pumpe d storage schemes and batteries deliver about 85% of energy used to charge them up.

It's a lot easier to store lots of energy as hydrogen (ideally as liquid hy drogen) but you do waste a lot of energy in the process.

--
Bill Sloman, Sydney

d

ems to acknowledge that CO2 does act to raise the global temperature of the planet. He must since he keeps talking about how beneficial it is to plan ts to have more CO2 and higher growing temperatures. So why does he think the AGW impact of sequestering carbon or at least not releasing more of it is really about the albedo???

Actually, he has been brainwashed by the denialist websites he uses to do h is thinking for him.

--
Bill Sloman, Sydney

It returns the solar insolation to space.

One thing I know for sure is that the sun doesn't shine at night.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Actually it does, but for half the day the bulk of the earth shields your bit of the planet from direct sunlight.

Only an egomaniac would think that the sun wasn't shining when he couldn't see it.

--
Bill Sloman, Sydney

NIGHT,

ly

There are times when you are the most ignorant person posting in this group . You literally have no idea what is going on. Even if the sun is not shi ning on your square meter of white when it is on the dark side of Earth, wh at is going on that would impact the temperature of that square meter? Do you have any idea?

Rick C.