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Solar Panel Splits Water To Produce Hydrogen (ieee.org)
schwit1 shares a report from IEEE Spectrum: A team at Katholieke Universiteit Leuven, or KU Leuven, says it has developed a solar panel that converts sunlight directly into hydrogen using moisture in the air. The prototype takes the water vapor and splits it into hydrogen and oxygen molecules. If it scales successfully, the technology could help address a major challenge facing the hydrogen economy. A small but growing number of facilities are producing "green" hydrogen using electrolysis, which splits water molecules using electricity -- ideally from renewable sources such as wind and solar. Other researchers, including the team in Belgium, are developing what's called direct solar water-splitting technologies. These use chemical and biological components to split water directly on the solar panel, forgoing the need for large, expensive electrolysis plants.
KU Leuven sits on a grassy campus in Flanders, the Dutch-speaking northern region of Belgium. Earlier this month, professor Johan Martens and his team at the Center for Surface Chemistry and Catalysis announced their prototype could produce 250 liters of hydrogen per day on average over a full year, which they claim is a world record. A family living in a well-insulated Belgian house could use about 20 of these panels to meet their power and heating needs during an entire year, they predict. The solar panel measures 1.65 meters long -- roughly the height of a kitchen refrigerator, or this reporter -- and has a rated power output of about 210 watts. The system can convert 15 percent of the solar energy it receives into hydrogen, the team says. That's a significant leap from 0.1 percent efficiency they first achieved 10 years ago.
KU Leuven sits on a grassy campus in Flanders, the Dutch-speaking northern region of Belgium. Earlier this month, professor Johan Martens and his team at the Center for Surface Chemistry and Catalysis announced their prototype could produce 250 liters of hydrogen per day on average over a full year, which they claim is a world record. A family living in a well-insulated Belgian house could use about 20 of these panels to meet their power and heating needs during an entire year, they predict. The solar panel measures 1.65 meters long -- roughly the height of a kitchen refrigerator, or this reporter -- and has a rated power output of about 210 watts. The system can convert 15 percent of the solar energy it receives into hydrogen, the team says. That's a significant leap from 0.1 percent efficiency they first achieved 10 years ago.
a solar panel that converts sunlight directly into hydrogen using moisture in the air
I didn't realize hydrogen was made out of sunlight. Perhaps the writer meant "converts moisture in the air directly into hydrogen using sunlight"? Although I still wonder what happens to that oxygen, I guess it goes poof, or transmutes into hydrogen.
Corruption is convincing someone that the selfless ideal is the same as their selfish ideal.
you can see it in action here:
https://www.vrt.be/vrtnws/nl/2019/02/24/belgische-wetenschappers-kraken-de-code-voor-betaalbare-groene-w/
The average Northern European home can't fit 20 of these panels on its roof. Unlike PV solar panels, these things have an added benefit: the hydrogen can be stored for later use without the need for expensive batteries... but you will likely need to compress the hydrogen which requires a fair bit of energy. Do they foresee these panels being used in residential installations, or are they more suited for solar farms?
Regardless, it's an interesting development. Good advances in hydrogen storage and transport have been made, and there's already a few hydrogen cars on our roads, but the production of green hydrogen (i.e. not produced from natural gas) has been expensive and troublesome thus far. Though the secrecy surrounding this project is generally a red flag for inflated expectations.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
A month ago the Belgian media suddenly started churning out news bouts how hydrogen "could save us" (see bible for other stories).
I will not deny that hydrogen has a good potential for storing energy - although at very low efficiency.
The only thing I like about this fairy tale is that the professors in the old lab where I once was a technician, and where I found my wife, finally started working together.
20 panels of 1.65m to provide energy for one house and a little hydrogen storage somewhere against cost of panels and storage = fairy tale.
This is what the Martians did. They became a full hydrogen economy. They converted a lot of their planet's water into hydrogen and it escaped into space! They didn't have enough fresh water left to sustain their economies. The resulting wars left lots of craters.
And their atmosphere got so thin without moisture that it was blown away by the solar winds. Over thousands of years, the solar radiation and planetary dust storms degraded everything and turned it all to dust.
So decomposing 1 liter of water (1 kg) into elemental H2 and O2 requires -(-237.14 kJ/mole) * (1000 g/kg) / (18.015 g/mole) = 13163 kJ/kg = 13.163 MJ/kg.
So if you could magically hold this panel under the noon sun for 24 hours a day in cloudless weather, it would take (13.163 MJ) / (31.5 Watts) = 417873 seconds = 4.836 days to decompose 1 liter of water into hydrogen and oxygen gas.
Under realistic conditions (i.e. fixed panel, sun moves across sky, weather), the average capacity factor for PV solar in the continental U.S. is about 0.145. So this panel would on average put only (31.5 Watts)*(0.145) = 4.57 Watts into cracking water. And it would take 33.4 days to convert 1 liter of water into H2 and O2 gas.
So you're gonna want to hook up thousands of these to some power lines, and transmit the electricity they generate to a large, expensive electrolysis plant. That plant will use the aggregate power from a thousand panels to to generate H2 gas in a more timely fashion. 48 minutes per liter of water.
210 Watts peak * 15% efficiency
WP already includes the efficiency figure, it's the maximum power put out by the panel under ideal conditions. At peak production, 210 W will go into hydrogen production.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
I'm still surprised and curious to know how this process goes on. WHEEL ALIGNMENT PORTSMOUTH
The major benefit of this approach is that it bypasses the storage problem of traditional solar panels: the hydrogen can be stored in a high-pressure tank analogous to the ones used for natural gas. Store in summer, consume in winter.
Currently, from an energy ROI POV, hydrogen as a fuel is just about useless; it can either be produced from fossil fuels, which is exactly what we do not want, or we can make it through electrolysis, but this approach is wildly inefficient compared to just using the electricity directly, like we do now.
Just about the only chance to make hydrogen as a fuel worthwhile (compared to electricity production) is if we can use availably energy _directly_ for electrolysis or thermal decomposition in a way that's more efficient than making electricity. Since PV panels are wildly inefficient (albeit significantly more efficient than photosynthesis), a solution like this might turn out to be a game changer, making a hydrogen economy feasible instead of a subsidy-fueled wildly inefficient pipe-dream.
Also, for production of rocket fuel on other planets or the moon, this thing might be turn out to be big.
0x or or snor perron?!
If it scales successfully, the technology could help address a major challenge facing the hydrogen economy.
Narrator: It didn't scale successfully. I'm not surprised to see Toyota's name mentioned in the piece either. They've been flogging the hydrogen dead horse for years rather than developing their own EVs.
Using sunlight to generate hydrogen seems wasteful. Might as well just generate power unless somehow
the hydrogen produces more power than it took to split it which I very much doubt.
If the benefit is storing hydrogen for future use I'd remind that hydrogen fuel cells need to be replaced frequently due to electrode CO2 poisoning.
The panel uses
catalysts, membranes, and adsorbents
Those sound a lot like consumables to me. That's the question with any "breakthrough" of this sort is just how much stuff does it consume and how much does that stuff end up costing (in energy, carbon emissions and pollution as well as monetarily).
Solar panels are pretty dang amazing as they are static and essentially last forever (or at least for multiple decades), unlike pretty much every other form of energy generation we know of. So by associating the hydrogen generation with solar panels they are asserting that kind of longevity and hands-off operation.
Better known as 318230.
Hydrogen and oxygen are together the most powerful non-nuclear explosive known. Lets get that into every house, huh?
E Proelio Veritas.
Mod parent up.
Also, today's production solar panels aren't much more efficient at producing electricity, and they're already at the point of economic viability. This takes panels of similar efficiency, and converts directly to a flexible storage medium: hydrogen.
Scaling and incremental efficiency improvements are the keys here: does it require expensive/rare/dangerous materials to produce this panel? Can it be mass-produced? Usable lifetime?
I'd still bet against this specific tech saving the world, but it could spur further research that could increase the rate of evolution to the point it becomes viable.
Can we make a solar panel that directly converts carbon dioxide into carbon and O2? That'd be more interesting.
..oh, wait, they're called plants! Why can't we plant more trees?
... a grassy campus in Flanders, the Dutch-speaking northern region of Belgium
I'm not a linguist, but I know enough Vlaams, Dutch, and Afrikaans, and I've been to Belgium on several occasions; enough to know that they don't speak Dutch in Belgium.
Just like Czech is not the same as Slovak, or Polish. They're similar, no surprise there, but they aren't the same.
Fission plants do it better.
I guess you also have definitely to be in Belgium to passively find ~1m of water in air moisture per pannel and per day in the air.
The problem with making steam or splitting water is the minerals and gunk in the water eventually foul the solar panels. This is why, fo example, a recent innovation in non-contact low emissivity steam generators is a big deal. It's not that they improved the low emissivity desgin it's that they came up with a way to heat the water radiatively without it touching the expensive and hot parts.
Second if you are going to use electrcity to split water then, since solar panel electricity generation is ineffieinet you are better off using the solar power to pre-heat the water with waste heat ( this makes it significantly easier to split since you are paying a down payment on the free energy needed to go from liquid to gas phase).
If you first make electricity to split it then making sure the electrical generation part doesn't touch the water itself is needed.
Some drink at the fountain of knowledge. Others just gargle.
Depending on the form of the vapor it may have a lower free energy to release the gas than a full liquid
Some drink at the fountain of knowledge. Others just gargle.
210 Watts peak * 15% efficiency
WP already includes the efficiency figure, it's the maximum power put out by the panel under ideal conditions. At peak production, 210 W will go into hydrogen production.
Actually the GP read it right I think. I agree the wording in the article is not perfectly clear so your reading might be right also but to me it seems to say that the panel uses it's 210 watts and with that the conversion effeicieny to hydrogen is 15%. I base this reading on the next sentence that says the conversion used to be less than 1%. Any solar panel would be more than 1% efficient in making power, ergo this must be referring to the conversion to hydrogen bond breaking not the solar panels energy production.
So the GP is right I beleive. That is, it's a liter a day per panel at full sun.
Some drink at the fountain of knowledge. Others just gargle.
Even scheme that I've seen that involves getting water from air always falls apart when you look at the energy cost to change water vapor to liquid. Why not start with a few liters of already liquid gray water to split?
One line blog. I hear that they're called Twitters now.
a) solar panels produce DC electricity, always have
b) DC electricity can split water, just put the two ends of the circuit into water and it happens
c) capturing moisture is easy, although is not voluminous
might be more economical.
Typical comercial PV panels are rated at about 125-165 Watts/m^2. So panels 1.66 x 1 meters yielding 210 Watts would correspond with 125 W/m^2 panels.
If the 210 Watts were after the 15% efficiency of electrolysis, then your panel would be producing 210W/0.15 = 1400 Watts. That exceeds the amount of solar energy the sun puts out. The solar constant (total energy of sunlight reaching the Earth) is only 1362 W/m^2. And that's out in space. The Earth's atmosphere absorbs roughly half that, leaving about 750 W/m^2 of total solar energy to reach your solar panel. The panel's efficiency (typically around 16%-21%) drops that to 125-165 Watt/m^2 of electricity generated from the sunlight.
So there's no way the 210 W figure is after accounting for the 15% efficiency of the electrolysis process. 210W is how much power you get from the panels. And the 15% efficiency of the electrolysis drops it to 31.5 Watts put into cracking water.
The article states: "The system can convert 15% of the solar energy it receives into hydrogen". Not 15% of the solar energy it converted into electricity which it does not do, it uses "direct solar water-splitting", whatever that means. There's no intermediate step with an efficiency of 15%, that figure is for received solar power to hydrogen, for an equivalent of around 210WP. Just think: if the actual output was 15% of 210WP, then 20 of these panels would be nowhere near enough to power and heat a home.
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
Anytime you see the words 'water from the air,' your scammy sense should be going off the chart.
Under nearly optimal conditions, one cubic meter of air contains roughly 30g of water vapor. 30g of water vapor is most assuredly not a wellspring of water compared to say a small puddle of water after a rainstorm. So, for the umpteenth time, the only things you can efficiently get from the air is nitrogen and oxygen.
Your scammy sense should also fire off when you read the phrase '250 liters of hydrogen per day.' Beware when someone is using 'strange' units to describe their results. While 250 liters is quite a large VOLUME, the density of hydrogen translates this volume into about 22g (GRAMS) of hydrogen. Since a traditional hydrogen fuel cell car has a fuel tank that holds 5kg of hydrogen, this prototype would take 2/3 of a year to fill one vehicle (with a range of roughly 225 miles or 360km).
Another scammy sense alarm should go off when you read '15 percent of the solar energy it receives into hydrogen.' Your typical industrial photovoltaic panels are roughly 30% efficient in converting solar energy into electricity. So you are losing 50% of your potential by 'converting it to hydrogen.' Just store the damn electricity in a battery where you get over 90% efficiency in storage/retrieval.
Please, please, please, please people -- don't fall for yet another scam -- don't donate untold amounts of money to these idiots' funding campaigns -- JUST SAY NO!
H2 gas at atmospheric pressure is useless. It costs more energy to compress it for storage than it holds in energy. They are also grossly underestimating personal energy consumption. Even if one could find a way to make use of H2 gas at 1 atmosphere, they are essentially claiming that 2 litres of gasoline/day will satisfy a family's energy needs all year.
This is nothing more than academic tom foolery.
Please get this out there. There is a number of studies that demonstrate that H2 is bad, very bad, for the Ozone layer. The problem is that H2 is light, very light and it is subject to atmospheric escape (https://en.wikipedia.org/wiki/Atmospheric_escape). On its way up and out it will pass through the Ozone layer where H2 is highly reactive to O3. The result is H2 + O3 > H2O +O2. So you end up with either water or hydrogen peroxide in the ozone layer. That is bad for 2 reasons. 1) it causes stratospheric cooling which impedes the production of ozone 2) Water at this layer interferes with the ozone production while providing not protection benefits.
http://web.stanford.edu/group/...
http://www.theozonehole.com/hy...
https://www.caltech.edu/about/...
https://sciencing.com/hydrogen...
https://www.geos.ed.ac.uk/~dst...
I wonder how the build cost per square meter compares to PV panels. I saw an article a while back telling about people at Sandia inventing a way to use solar to directly split hydrogen from water. It involved making a parabolic reflector and having a small amount of catalyst at the focus. I remember thinking at the time that reflector seems much less expensive per square meter to build than does PV panel, so even if it's a less efficient use of sunlight, if you've got the space and the build is cheap, it makes sense financially. Plus, the hydrogen is easy to store for use at night time. I'd post a link, but it seems the article has disappeared.
No, not really. Would you refer to Holland as the Flemish-speaking country north of Belgium? Well then!
The difference is a bit more than the difference between Oxford English and broad Glaswegian.
210 Watts peak * 15% efficiency = 31.5 Watts going into decomposing water at peak production.
re-read the article. 210W *is* peak efficiency -- it's 15% of the average daily insolation, as the article plainly states. The article's numbers add up, and yours do not.
Absent this error, your argument for a large centralized processing plant collapses. It's almost as if you deliberately misread the article because you have some vested interest in preserving the current centralized power infrastructure. I have to ask: are you now, or have you ever received funding from any Koch-backed source?
I'll bet the answer is "yes."