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Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

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Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#121

Post by adwn »

taneq wrote: post #93
OscarCunningham wrote: post #41

From the title I thought the article was going to be a sarcastic description of plants.

Even if it's completely inorganic, plants (or algae cultures, etc) are a necessary comparison for anything like this, but that never seems to come up. It's like announcing the invention of the motor car without comparing it to a horse.

> Even if it's completely inorganic, plants (or algae cultures, etc) are a necessary comparison for anything like this, but that never seems to come up.

Probably that's because plants are typically only 2-3% efficient when it comes to their use of sunlight, and then it's still a long way (energetically and logistically) to usable fuel or electricity. Plants are really not a good comparison benchmark here.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#122

Post by shadowmint »

jcoffland wrote: post #114
Animats wrote: post #35

"Nanotechnology" again. It's just surface chemistry, people. It's nice that they can do this in the lab, but as usual, the PR is excessive. "The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. Especially since UC Berkeley announced a similar breakthrough last year.[1] Wikipedia points…

> Does the catalyst get used up, or crud up with contaminants, and if so, how fast? What limits the life of the system? What are the costs like? (Excessive catalyst cost has been a problem.) If you had actually read the whole article before commenting you would know the answer to these questions. Your questions about efficiency are however valid.

I read the article and the answers certainly weren't clear to me.

'20x cheaper than some other catalysts' what does that mean exactly?

'special fluid keeps catalyst sites clean' does it get used up in the process? Is the fluid expensive and hard to manufacture?

The devil is in the detail here.

How exactly does this compare to other state of the art similar approaches? 10x cheaper? 2x cheaper? on par?

I think it's pretty valid to argue the article is doing some vague hand waving without actually saying if this is meaningfully better than other approaches.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#123

Post by dredmorbius »

maerF0x0 wrote: post #94
dredmorbius wrote: post #50

Earlier quoted context omitted.

Solar cells don't just sit there without intervention, and have larger up-front capital and labour costs than planting an orchard, or more appropriately, fuelwood or timber forests. And have a lifespan of 20-25 years. Plants are a pretty neat technology, all told.

I dont know how much they differ but planting trees has lots of cost. I estimate the cost of planting is something like $3 per surviving tree. (Cause you usually over plant assuming many will die).

Depends on the tree.

For some forestry applications, seeding is done from the air.

Note that if you're growing wood for fuel, you're not worried about grafting stock, or the net health (much), or overcrowding (you can thin later if necessary), etc.

Planting orchards is, as it happens, pretty expensive. But that's also a pretty high-end case, and the expected life is generally 20-50+ years. Upwards of 300 in cases (olives, grapes, and citrus).

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#125

Post by continuations »

the_duke wrote: post #81
wongarsu wrote: post #71

Earlier quoted context omitted.

>"The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. They don't really say that they are cost comparable to gasoline, they just make the obvious statement that if something were as cheap as gasoline that would be a big deal. I guess hyping these advances is supposed to make it easier…

To be fair, I never read anything about fusion being 'just around the corner'. The most optimistic estimates I know of talk about commercial viability in a 30-50 year timeframe.

Well Lockheed Martin claimed they'll have a 100MW fusion reactor small enough to fit on a truck up and running by 2017 and a fully operational grid-ready machine by 2023:

http://www.americansecurityproject.org/lockheed-martin-outli...

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#126

Post by Godel_unicode »

callesgg wrote: post #29
Godel_unicode wrote: post #11

Earlier quoted context omitted.

The key difference in my opinion is that this process would not be competing for land with existing crops. We could do both.

Yes it would, sun rays only hit the ground once.

Really, you can't think of any places where there's sunlight and water but no crops are grown?

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#127

Post by Godel_unicode »

mattashii wrote: post #52
lorenzhs wrote: post #47

Earlier quoted context omitted.

There are plenty of areas of this planet where plants don't grow because the climate is too harsh (not enough water and/or extreme temperatures)

I understand your point, but this system also requires water, and therefore does compete at that point as well. Higher temperatures also have a negative effect at the efficiency of solar panels, but they are indeed a lot more resistant (typically lower temperature=better efficiency for solar panels).

Cold, water, sunlight, no crops, existing infrastructure for moving fuels. Alaska? There's even high CO2 there from wood stoves (Alaska is 4th per-capita).

http://www.eia.gov/environment/emissions/state/analysis/

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#128

Post by evgen »

efng wrote: post #74
HillaryBriss wrote: post #51

Earlier quoted context omitted.

> ... take the CO and pump it underground then you are actually producing fertilizer for agriculture Interesting. How does the CO fertilize the plants?

I assume he meant carbon sequestration.

Yes, my prose was a bit less clear than I had intended. You can oxidize the CO and be carbon neutral or sequester it and be carbon negative.
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