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Mimicking Photosynthesis To Split Water
plantsdoitsocanwe writes "An international team of researchers led by Monash University has used chemicals found in plants to replicate a key process in photosynthesis, paving the way to a new approach that uses sunlight to split water into hydrogen and oxygen. The breakthrough could revolutionize the renewable energy industry by making hydrogen — touted as the clean, green fuel of the future — cheaper and easier to produce on a commercial scale." This was a laboratory demonstration only and the researchers say they need to bring up the efficiency.
yawn...
We hear about so many "breakthroughs" that turn into vapors that you really can't believe any of them anymore. Try sticking to solutions that we can implement today, especially conservation initiatives that are guaranteed to produce cheap, green fuel by simply not using them.
Why not just put in a solar panel? 3x the efficiency of the best plants and none of those messy chemicals, plus much better applicability.
I agree with you. How about these guys?
http://web.mit.edu/chemistry/dgn/www/research/e_conversion.html
They bounced into the news a few weeks ago.
The diversity and expression of human opinion is essential to human survival.
Actually, your answer to why your car doesn't run on solar yet is rather simple. Because we haven't needed solar power to win a war yet. Nuclear got everything it needed to get off the ground, working, demonstrated, and dropped. It was needed to fight a war. Radio, space ships, etc? Same things. The US Military is just starting to come to the conclusion that half their vehicles exist solely to deliver fuel and supplies to the other half(the fighting half) and that there is a huge risk in running tankers full of Diesel and gas to forward areas, as they become very easy targets. Destroy the supply lines, and those 70Ton M1A tanks become very large, immobile targets. Add to that, the skyrocketing cost of fuel the military has to buy. (not to mention, the huge costs of keeping 50% of your peopled tied up in support roles).
THat is why the military is starting to look at things like solar, small nuclear plants, etc. They are looking at hybrid vehicles that work like a train, the whole powertrain is electric, powered by a generator. Some of these vehicles are pretty cool, they could sit there and idle at the forward CP, and you just plug all your radios and equipment into the truck. No need to lug a generator with you.
I have a feeling things are going to improve quite quickly over the next few years. Nothing improves technology like fat government contracts!
What are we going to do tonight Brain?
If you had to apply a potential of 1.2V to catalyse the reaction then that is OK so long as the process is chomping very little current and is instead getting the bulk of the energy from the light.
Of course if it is using a lot of electrical energy and just a small amount of light energy then it isn't really much improvement over electrolysis.
Engineering is the art of compromise.
I think focusing sunlight to thermolyse water in that way might violate thermodynamics. I think you'd need to get closer to the sun. Maybe someone can give us hard numbers...
In the late 1980s a mountaineering stove came out that could run on those fuels - the whisperlight international. Admittedly one of the first of them was hurled into a crevasse on Mt Erebus in Antarctica by a critic. However the later ones were better and there have been lot of other multi-fuel stoves since then.
How many plants move around? How many animals use photosynthesis to get the energy to move around? What is the ratio of plannts / animals in the world?
If evolution is a teacher it is telling us that sunlight is so diffuse that you need vast areas of collectors to power even a small number of things that move about. Unfortunately, we want to move a lot of stuff using minimal impact on our surroundings, so we want something less diffuse in nature.
That is very much how the motor car industry started out - you had well over 3000 startup companies all across North America and Europe, experimenting with the combustion engine, and inventing different improvements (carburettor, cooling fan, 2-stroke, 4-stroke and 8-stroke engines). Eventually, over time they merged together to form larger companies and eventually forming a handful of corporations.
How many solar panels would they need on a car to have a completedly closed system (solar panels to generate electricity to split water into hydrogen, a compressor to force the hydrogen and oxygen into the engine, and a collector to recycle the used water from the exhaust)?
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
Photosynthesis has a maximum theoretical efficiency of about 11% from sunlight into energy stored in biomass (eg. the plant). But in the wild, it's only 3-6% efficient.
Familiar PV cells already get 15-25% efficiency; experimental concentration cells get over 45%. And the PV outputs electric current, not just biomass to burn inefficiently.
Those cells cost a lot more energy to make than plants do, but they last over 30 years, while most plants don't.
I'm not so sure that mimicking photosynthesis is such a great way to go.
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make install -not war
FTFA: This process of "oxidizing" water generates protons and electrons, which can be converted into hydrogen gas instead of carbohydrates as in plants.
Well, hydrogen is nice and all, but I can see an equally compelling reason to work on generating carbohydrates (preferably edible) with this method instead. Especially in places with no plants where having a food source would be awesome - places like long-range manned space flights, as-yet-un-terraformed planets like Mars, and god-forsaken hell-holes like the middle east and the Sahara.
"Soylent green is...well, it's sunlight and carbon dioxide...and 1.2 volts"
Nothing worthwhile ever happens before noon
Correct except you've forgotten about the Corona Problem. The Sun's corona is more than a million degrees and nobody knows why yet. Probably some magnetic field effect, but if we can harness the effect and keep it going much further out from Sol, we can heat all the water you need.
It would work just like Doc Smith's Sunbeam, except you wouldn't be shooting at inertialess planets (much).
"I improvise. It's my greatest talent. I prefer situations to plans..." --Wintermute, William Gibson's "Neuromancer"
Nah, after GUT there's still TOE to shoot for. And after TOE we can really start developing theories about parallel universes with twisted GUTs and ticklish TOEs. There's always more work.
And if all else fails, there's always the "soft" humanist sciences. There's as much work there as you can make up.
It's better than that. If you take non-potable water and produce pure hydrogen, then when you burn the hydrogen you get potable water. One popular demonstration of the "greenness" of hydrogen cars is to catch the water dripping from the tailpipe in a glass and drink it. I'd only try that if your hydrogen is pure, of course. ;-)
I still favor electric vehicles over hydrogen, however, at least for the next few decades. Electrics have only one significant problem stopping mass deployment - energy density of batteries. Hydrogen has many - the cost of producing hydrogen, the cost of compressing or liquefying the hydrogen, the impermanence of liquid hydrogen ("venting"), the safety concerns of carrying around enough hydrogen to power a car without a "Hindenburg effect", and the cost of a new infrastructure to transport megatons of hydrogen to fueling stations scattered across your country.
Or maybe that's just my EE degree coming through.
Indeed another interesting thing is this would allow for a submarine engine with incredible efficiency as it would in effect have an infinite fuel source with the need to only refresh the catalyst materials. Also by eliminating intake on the car we eliminate the need for another maintenance part. The largest issue I see is using water in freezing climates.
OK, given that hint I went here. The technology looks reasonably mature (except perhaps CO2 capture from the air), again just a cost issue to get artificial hydrocarbon prices down to petroleum price ranges (easy to say, harder to do :-).
I'm still favorable toward electrics, because we can produce electricity cheaply already from a relatively large number of mature technologies - including hydrocarbon-based fuel cells or engines - and the distribution infrastructure is multi-use (not just for engines).
But again, when you're EE, electricity always looks good. My house in Texas is 100% wind powered (sorry, Kermit, but it is easy being green :-). I even mow my yard with a Black & Decker plug-in mower and plug-in weed eater. Never needs a tune-up, or oil change, or new spark plugs, and it's high power under torque. Given my 45 mile round trip commute, I'm very interested in an electric commuter car.
Instead of hydrogen, why not just make more efficient hybrids
Because you're still dependent on gasoline, obviously.
The technology is already there,
Hydraulic hybrids are less developed than even EVs and PHEVs, let alone hybrids.
without the need to worry about recycling the Li batteries in existing hybrids,
1) Existing hybrids use NiMH, not Li-ion (and certainly not Li)
2) Li-ion batteries, depending on the type, are either minimally toxic or nontoxic. NiMH should be recycled, although it's not a travesty if you don't. The types that are really critical to recycle are lead-acid and nickel cadmium.
and they are more efficient
Their regen is more efficient than NiMH regen, but not more efficient than regen with automotive li-ions or supercaps. Furthermore, regen is the *only* benefit they give you. Hybrids aren't all about regen, you know; that is just *one* energy-saving technique that they utilize.
I once listened to a Philip Glass record for an hour and a half before I realized it was skipping.
No, they're starting with the exact same (expensive) membrane used in fuel cells -- nafion. They've just taken this membrane and added a manganese-based catalyst to it.
I'm amazed that most people never point out the huge, glaring flaw in this notion of setting up big solar electrolysis plants in the sunny desert southwest. Let's ignore the problems of how corrosive the released hydrogen is to your system, which usually makes solar electrolysis have short lifespans. Let's do the same with the free oxygen. And the water. And let's ignore algae growth, which is a problem in most systems that mess with water. And let's ignore hydrogen embrittlement when it comes to raising storage and transportation costs. And let's ignore how huge hydrogen storage tanks have to be due to its very low density, a fact that makes the prior issue even worse. And let's ignore that it has a ridiculously low ignition energy, burns in almost any fuel-air mix, readily evolves deflagrations to detonations, pools under overhangs, enters pipes and follows them to their destinations, burns clear and vigorously, and so on. And let's ignore that leaked hydrogen destroys ozone. And let's ignore that fuel cell stacks are quite inefficient, and that a fuel cell stack strong enough to power a car will cost you hundreds of thousands of dollars. We're talking about *consuming lots of water in a desert* -- enough to power vehicles around the world. What the heck kind of plan is that?
Electricity is our common energy storage and usage medium. Why are we talking about "very low" efficiency, in-the-lab, probably horrible lifespan and very costly hydrogen-solar cells when we could put photovoltaic cells or solar thermal on the same land, get much better effiency from a much cheaper system, transmit the electricity efficiently (92.8% average in the US), rectify it efficiently (~93% charger efficiency), charge/discharge it efficiencly (96%-99.9% in li-ion), and convert that to kinetic energy efficiently (85-90% typical electric motor efficiency in a normal drivecycle), in a vehicle that uses batteries that cost *literally* an order of magnitude less than said fuel cells, can level-3 charge in as little as 5-15 minutes (depending on the type), and have longer lifespans to boot?
The "hydrogen economy" is just a silly concept; nothing about it makes sense in comparison to an EV economy with modern automotive li-ion batteries.
I once listened to a Philip Glass record for an hour and a half before I realized it was skipping.