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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

#71
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…

>"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 get funding for further research in the area. The sceptic in me expects them to hit the market right after the first fusion power plant comes online (another technology that is hyped for decades as "just around the corner").

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

#73

Earlier quoted context omitted.

100w is closer to reality for most places. 1000W per meter squared is an ideal case for some near-equatorual desert at noon with very clean air.

Sorry, no. 100W/m2 is highly unusual for any place on Earth. Take the most overcast midday conditions you can imagine and they'll exceed 100W/m2 by a comfortable margin. That can be in Germany, Canada, Colombia, or Antarctica. If it's sunny, it's very close to 1000, no matter where you are. Partly cloudy can even exceed 1000, since clouds can reflect additional sunlight onto the ground. Then there's of course nightti…

Sorry, yes.

You're only counting the peak hour of the day. And yes, there's also nighttime, morning, afternoon, and evening.

And guess what, nighttime is not zero. The moon gives off some light too.

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

#74
post #39

Earlier quoted context omitted.

Probably also worth noting that syngas is the primary input for the Haber-Bosch method used to generate the ammonia feedstock for most of our synthetic fertilizers. If you just take the CO and pump it underground then you are actually producing fertilizer for agriculture using a carbon negative process.

> ... 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.

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

#75

Earlier quoted context omitted.

I have regularly found that random HN commenters often turn out to have years of professional experience in the industries they are commenting on. Its one of the fun parts of reading HN.

But it'd be great to have an "ignore user" function for those few who just google their skepticism.

If their recently-googled skepticism is accurate, then I don't care how cursory it is - it saves me the five minutes of looking up the same sources myself.

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

#77
Isn't it counterproductive to turn it into fuel to be burned? It seems like that would leave us at best at no net new carbon dioxide, when we really should be sucking CO2 out and sequestering it away. How about we turn it into bricks or something...

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

#78

One way to make a system like this one more efficient/cost effective would be to draw the CO2 from ocean surface water which has a much higher concentration than the atmosphere, depending where you are in the world.

Flue gases with a high CO2 content are better than cheap; people will actually pay you to get rid of them. And we have a lot of them (this is kind of the problem in the first place). If you look at something like the exhaust from an oxyfuel turbine, you can get 70/30 N2/CO2 with relatively high purity.

For this reason, I'm always skeptical of atmospheric capture projects. It's just got to be more efficient to capture from a mixture with 20% (or more) CO2 than from a mixture with 0.04%.

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

#79
post #77

Isn't it counterproductive to turn it into fuel to be burned? It seems like that would leave us at best at no net new carbon dioxide, when we really should be sucking CO2 out and sequestering it away. How about we turn it into bricks or something...

like how a tree uses solar energy to turn air (CO2) into wood?

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

#80
post #77

Isn't it counterproductive to turn it into fuel to be burned? It seems like that would leave us at best at no net new carbon dioxide, when we really should be sucking CO2 out and sequestering it away. How about we turn it into bricks or something...

Ever heard of concrete? ;)
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