Solar Powered Chemical Processing 48
evileconboy writes "I found a great story about the creation of artificial porphyrin-based molecules that can absorb light like chlorophyll. The molecules absorb photons from porphyrin "antannae" charging a buckyball which acts like an acceptor. Apparently, the scientists want to use the molecule to drive other reactions. But I wouldn't be surprised if they could create a type of efficient, artificial leaf-like solar panel with these molecules. Forget silicon or other gallium based photovoltaic cells! "
Finally... (Score:2)
Cooool. Viridian industries. (Score:1)
Nifty fusions of the biological and industrial are the kind of things Bruce Sterling sees replacing smokestack industries. (Decentralized Vats of Vidridian Goop industries?)
Biomimicry (Score:1)
Yes! (Score:5)
But seriously, this is great news. Considering the shamefully small amount of money that goes into researching renewable sources of energy, I'm always delighted when they hit a new breakthrough. Solar is especially attractive - imagine running your entire home off a refrigerator-sized panel adhered to the roof. Total personal independence!
Unfortunately, there are severe limits at the moment. I recently looked into roofing a home with solar panels. Turns out that it would cost around $20k to be self-sufficient (and then only just barely). I worked it out, and it seems that with my monthly electricity costs, it would take me 103 years to pay that off.
http://www.mcn.org/a/mendom otive/Products/Unisolar2.htm [mcn.org]
The trouble is that even the theoretical output of solar cells is low. It's bounded severely by the surface area because of the limitations of the diode materials available to us today. Turns out that even if you have full light shining on the surface, you can only get about 29% efficiency - and that's theoretical. In reality, it's less. Here's a site that explains the technical details:
http://www.nrel.gov/ncpv/documents/ pvpaper.html [nrel.gov]
Now, I have heard some clever ideas for increasing the efficiency. For example, one team discovered purely by accident that they could increase surface area by making the silicon layer extremely "spikey" on a microscopic level. The sunlight bounces around inside the spikes and is more likely to ultimately by trapped by a cell.
I think the theoretical number they cited was 40% efficiency, but right now that's still vaporware.
I wonder whether some slashdotter is brave enough to post the original ACS paper. I don't have access. I'd love to see what efficiency numbers these people are touting. Anybody?
-konstant
Other isotopes? (Score:1)
Does anybody know if they tried this with the other isotopes (C-70, C-120, C-160, etc.)? C-60 is the most common, but I wonder what effects this process would have if they used larger buckyballs.
Carbon balls (Score:4)
... (Score:1)
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Re:Yes! (Score:3)
The best efficiencies I've seen so far is about 17% so its not that great. OTOH the efficiencies of combustion engines and power plants are only on the order of about 20-40%. I believe that maximum efficiency possible with Carnot egnine is about 40% with the current temperatures our engines run at.
Coolness epitomised (Score:2)
God, I love buckyballs. They can do anything. A beowulf cluster of these'd probably outcalculate Deep Thought.
Solar furnace (Score:1)
Re:Yes! (Score:1)
Re:Yes! (Score:2)
Re:Biomimicry (Score:1)
Some questions left... (Score:4)
1. How suitable is this material for mass production ?
2. How much power can be generated per unit area ? I'd like to see the "theoretical maximum" and the actual measure of the current material. This would allow elementary comparisons between solar collector's and chlorophyll. This sounds like a great breakthrough, but exactly how good is it compared to what we have ?
3. What frequencies can the material respond to ? This question could be important to the space program, if materials can be made that convert even a fraction of the radiation from the sun to usable energy there could be a great saving in mission mass requirements ? This could come from simply replacing inert shielding with this material, thus you eliminate some power generation/fuel requirements, making the whole mission more efficient. Using this material as the membrane of a solar sail would be doubly effective, deriving propulsion as well as any energy requirements.
4. My previous inquiries beg the question, What is the tensile strength of this material ? How malleable is it ?
Again it is clear the technology is far from ready for prime time, but the possiblities are exciting.
It's still a while a way (Score:4)
(*)- Yes I'm aware you could create a system to generate a system that say generates ATP, and then uses the ATP to fuel a reductase or oxidase in order to run an electrolytic cell. This sort of system may work well for biological systems which have power consumptions on the order of 120 W (this is based on energy requirements of 2500 Kcal/day, fyi 1 Calorie in the nutrional sense equals 1000 calories in the biological sense). Photosynthetic systems work great in biology since plants concentrate energy over long periods of time, e.g. it takes 3-4 months to generate the energy required to produce a couple ears of corn.
Question: Reverse reaction? (Score:2)
Article missed a bet. (Score:3)
The cell voltage (under light load) will be the voltage difference up which the pophyrins can push the electron (probably about the electron-volt equivalent of the associated photon), less any potential-differences the electron must travel getting from the buckys to the negative wire and from the positive wire back to the pophyrins.
Re:Other isotopes? (Score:2)
Have they redefined basic terms since I had chemistry back in high school? Different sized buckyballs wouldn't be different isotopes (different atomic weights of same element due to different neutron count), or even different isomers (different structures made of same set of atoms), they'd be different molecules. Or did someone sneak crack into my rootbeer?
And here it is - explained! (Score:1)
I didn't quite understand that article so i babelfished it...now I got it
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Or and chemistries had constructed a molecule that imitated the capacity with the green ones of factories to block light of the sun and to use the energy for the photosyntheses. The so artificial light-light-light-light-light-light-light-light-l
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I don't know which books I enjoy most, those who keeps me awake, or those that makes me sleep. -Benjamin Disraeli
Make that "porphyrins" (Score:2)
Re:Some questions left... (Score:2)
The energy incident on the Earth can be calculated by estimating the energy the sun emits (assume its a 5500K blackbody) and then figuring out how much is incident on a disc of the earth's diameter at ~ 1 AU away. If I remember right, the figure comes out to something like 14 W/m^2 within an order of magnitude. If we achieve the same efficiency plants do we'll be able to get about 30-40% of it in usable form (which is damn good).
What frequencies can the material respond to ? This question could be important to the space program, if materials can be made that convert even a fraction of the radiation from the sun to usable energy there could be a great saving in mission mass requirements ?
You can tailor its frequency response by attaching side groups to the porpyrhin rings or by changing the conjungation of some of the bonds within the rings. Most chlorophyll is most sensitive at about 720nm and 640nm since the sun's energy output peaks there.
Unfortunately this sort of material wouldn't be too effective in space without a lot of shielding. Most organics are fairly fragile and exposing it to the conditions in space would cause it to break down. Add in high energy photons(gamma, UV, x-ray) and the molecules start breaking down quickly.
Proof-of-concept only (Score:3)
1. Manufacturability: These guys have connected 3 molecules of porphyrin to "conducting arms" and to a fourth "custom modified" porphyrin with a buckyball on it. That's a whole lot of custom reactions. Even if you could run these reactions in a vat instead of a test tube, there have to be at least a few of them where the maximum theoretical yield is pretty low.
2. Efficiency: as the article explained, real photosynthesis has to hand the electrons off many times before it can get useful work out of them. Things may get easier when you want electrons out the end instead of ATP, but this is still only the first step. And even in this step, you've already lost a lot of the energy. The reason a buckyball ion is so stable is that the charge distributes over 60 atoms of carbon. The electron is pretty happy there - it doesn't have a whole lot of oomph left to power your [wearable beowulf cluster].
Sure, this reaction may help us understand the chemistry of modified photosyntheses, but in the long run, I'd bet that the first green photocells will crib a lot more from life than just one part of one molecule. In other words, the pure chemists have to start talking to the genetic engineers a lot more than these ones have.
Re:Other isotopes? (Score:1)
It gets worse, the original poster was a chemical engineer. Of course he or she probably just had a mental slip up.
Re:Some questions left... (Score:3)
Re:It's still a while a way (Score:1)
I have been wondering for a while how to harness the "proton motive force" (which normally drives the proton-translocating ATP synthase), which would tap the system prior to the energy taking a chemical form (in the sense of chemical bonds). This gets me to wishing I had some engineering under my belt.
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Once in a while you get shown the light,
Re:Yes! (Score:1)
All the solar panel's for housing I've seen is of the amorphous variety.
Re:Other isotopes? (Score:2)
See http://www.dictionary.com/cgi-bin/dict.pl?term=al
Heinlein thought of this -- the other way around. (Score:1)
Re:Buckminster Fullerene Synthesis (Score:1)
Erro Bad Citation (Score:1)
Re:Yes! (Score:2)
--
Deja Moo: The feeling that
Should be "Bionics" (Score:1)
(And yes, the less-complete dictionaries only list the definition of bionics popularized by "The Six Million Dollar Man", i.e. machinery replacing/augmenting the organism, but the original definition was the study of biological systems. To quote Martin Caidin's "Cyborg" (which inspired the TV show):
"The term itself, bionics, still found ready understanding within only a limited area. Originally it was coined by Major Jack E. Steele, who had been a research psychiatrist at the Aerospace Research Laboratory in Ohio. . . . He created the word bionics as a combination of the Greek bios, meaning life, and the suffix ics, meaning after the manner of, or resembling. Steele taught his coworkers that the scientific goal of bionics was to acquire specific biological knowledge, then reduce that knowledge to mathematical terms (again with the indispensable computers) that would be meaningful to an engineer, who would then produce what the doctors, or the bionicists, if the term was preferred, requested."
(I happen to know all this since Dr. Steele (now Colonel, retired) is my father-in-law.)
(And a rev iew [umd.edu] of "Cyborg" suggests Martin Caidin may be the first user of term cyborg -- from which word of course derives the name of the Star Trek Borg.)
solar powered webserver colocation isp? (Score:1)
Greenstar [greenstar.org] is uber cool, but not quite for right this. KTAO [ktao.com] broadcasts a solar-powered 50,000 watt radio signal from atop a New Mexico mountain, but no backbone connect:/.. I'd try it w/ my DSL at home, but my landlord won't have it:\.. any leads?
your wearable is so primitive.. (Score:1)
Many computations don't require lightning-fast processes. We ought to look
into making many processes run through chemical catylists and handled by the
cells of the body. Phactories and Pharms could handle their own
computations using chemical process. Information can be stored on protein
nucleotide "tapes" written by DNA-like printers. Many solar and battery
personal devices could be run on this system, with much less demand for
electricity. It would be easy to harness motion to power such devices, as
well. A small, fast processor and memory card could be used for
communications and math-intensive processes and memory that needs to be
readily available. Wearables should give way to more integrated devices
that are almost indistinguishable from the individual. Use is first nature,
not second.
Working on a piece of fiction that paralells this:
http://thinktank.knoggin.com/th inc/pages/pharmboy.htm [knoggin.com]
Free Film project anyone?
Re:Yes! (Score:1)
It presumes you have Oil or such to burn, while the sun will be around for a few more billions.
To compare the efficieny directly, compare one acre of Biomass fuel fed to an engine vs
one acre of solar cells.
And perhaps they idea about solar powered reactions is that you could cut out the middle man:
only apply the power directly where needed.
rbb
Re:Coolness epitomised (Score:1)
THE EARTH...
What a dull name.
Re:Question: Reverse reaction? (Score:2)
Granted, they are silicon and not buckyballs, so that's boring, right?
Re:Yes! (Score:1)
UNSW Photovoltaic achievements [unsw.edu.au]
Re:Yes! (Score:1)
If it still remains high perhaps the best solar power is to grow sugar cane or beet, ferment, distill (use the waste heat from your engine for the stil) and burn the alcohol in an inf^Hternal combustion engine.
Re:Yes! (Score:1)
A material like this with a carbon backbone and basically bio-molecule characteristics would be pretty benign to dispose of. Of course, as is mentioned in many other posts, how this energy could be harnessed is a complete unknown at this point. But to my mind this seems to be a good step towards lower cradle to grave impact. Which makes it a great selling point with an infinitessimally small portion of the population, but a guy can dream can't he?
Cheers.