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Comment by hemogloben | Hacker News Reader

Just to put some numbers to this for anyone unfamiliar.

Climeworks currently estimates 2.5MWhr / tonnes of carbon (1000kg) (heat energy). That's an hours worth of energy for 2500 homes, PER 1000 kg.

Mammoth sounds like it'll capture (36000 ton per year / 365 days / 24 hr) ~4 tonnes an hour = 10MWhr.

Most solar farms in the US are currently less than 5MW and thus ALL of their energy couldn't support a single one of these capture facilities.

Two Comments:

1) All that energy for 36000 tonnes / year just doesn't seem like it is viable.

2) I don't really think we should be prioritizing using clean energy to recapture carbon over replacing other sources.

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I work in the carbon removal industry, and your calculations add up.

Where I encourage you to explore is what an equivalent unit of energy spent on developing new carbon removal systems is right now vs the equivalent unit of energy spent to make another solar panel. There's a trillion tons of excess carbon dioxide in the atmosphere, so even if we stopped every carbon dioxide emission tomorrow, the planet would still continue to warm for the next century.

My conclusion is that ultimately we need both, and that short term the energy spent on carbon removal solutions needs to be framed as an investment for it to make sense.

Honestly, those numbers seem pretty good to me for a first generation product. As a baseline, at Ontario electricity prices that means I can get my carbon emissions to net zero ignoring any zero lifestyle changes for ~$5000/an. That’s high, but not ludicrous. I assume you could find further savings by further R&D on the process and by integrating electricity production. Now add in lifestyle and other technological changes (EVs, more efficient homes, more responsible purchases, more renewable electricity generation, etc) and we’re IMO into highly viable territory.

Shouldn't the comparison be carbon removed by this per unit energy used vs carbon produced by hydrocarbon powered power plant per unit energy created? E.g doing the math with some looked up data, this removes 1 ton of carbon per 2.5MWH. One ton of coal generates 8.1MWH. One ton of goal generates 2.4 tons of CO2, So it my math is correct (please verify), this already runs at an efficiency ratio of (8.1 (MWH) / 2.4 (tons CO2) / 2.5 (MWH / tons CO2) ) = 1.35, which being larger than 1 already, means that hypothetically you could power this via a coal plant and have a system that is net carbon negative and/or has some extra power remaining? Obviously we shouldn't do that, but to me the energy efficiency here is pretty impressive.

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