I mean, it's typically much cheaper to capture CO2 from concentrated streams, such as the flue gases from coal-fired power plants. So why accomplish the same CO2 mitigation at higher cost by getting it from open-air capture?
Yeah, but your capture system will have to be insanely massive. Have you estimated how much air you’ll have to churn through? What risks are there to local fauna? You’ll have to collocate these all over the world.
Even in the long term, it seems like you'd want to grab CO2 from point-sources. Sure you might need to also grab CO2 from open-air if you reach such a scale, but even at that point open-air would just be a supplement rather than the sole source (unless there's a reason to favor open-air exclusively?).
So why start with open-air capture? Just seems weird to burn cash on a more expensive way of accomplishing the same goal.
> I agree, they're going for the harder problem, but it's also the most scalable solution.
It's not really harder, just more expensive.
When major point-sources give off CO2, it's more concentrated. Once it gets into the atmosphere, the entropy goes up, and that entropy cost must be repaid to capture it again. Technical challenges aside, it's still another cost to be paid, making it more expensive.
I think people like the idea of open-air capture because it's just so easy to imagine. I'd guess that it's also easier to pitch to non-technical investors, largely because it sounds so elegant in its simplicity. I just don't see how it makes much technical or business sense, beyond that sex appeal -- which, to be fair, I can appreciate having its own uses.
Honestly, I'm skeptical that a robust analysis of the economics would yield a favorable conclusion. But the market isn't entirely rational, and I can imagine a strategy that sacrifices a measure of fiscal viability for sex appeal potentially profiting for it -- I'm guessing most when pitching to investors, but potentially when pitching to policy makers and the general public?
Which I think is what I find so interesting here. I mean, this doesn't look like a technically optimal strategy to me, but perhaps that isn't necessarily a bad thing?
This is, say that they optimize the plan in a fiscal sense -- would it still get funding from investors? Would people still want to buy into it as hard? Would the HackerNews thread still have so many positive comments?
Investors financed total nonsense such as solar roads. You don't need to be efficient to get VC money, particularly nowadays with loads of free cash from the central banks and low interest rates.
I don't see how that will economically make sense long term. Burn coal to yield co2 + water + electricity, then use electricity to convert the co2 + water into oil? I assume it's more efficient to directly convert coil to oil: https://en.wikipedia.org/wiki/Coal_liquefaction
What they're doing makes more sense to my intuition. "Mine" (excess) co2 from the atmosphere, using a cleaner source of electricity.
I mean, if open-air capture is used, it's mostly just a higher cost -- switching to capture from point-sources should make it more efficient. But then it seems to demolish folks' evaluation of the proposal itself.
I suspect that it's that "mining CO2 from the atmosphere" concept that, when we talk about open-air capture, makes it feel like a closed-loop process. But when we talk about capture from point-sources, it seems to feel less like a closed-loop process, leading to a loss of that intuitive feeling you'd mentioned above.
I mean, it's typically much cheaper to capture CO2 from concentrated streams, such as the flue gases from coal-fired power plants. So why accomplish the same CO2 mitigation at higher cost by getting it from open-air capture?