pete1901 t1_ixcltuu wrote
It really all depends on how much energy the process uses and how that energy is generated. Current CO2 capture technologies produces several times as much CO2 in their energy use than they capture during operation. Obviously you could say "just use renewables" but unless the local grid is 100% renewable then it will still be causing CO2 generation by forcing other users off the limited renewable energy supply and back to fossil fuels.
UniversalMomentum t1_ixcorss wrote
That seems like a silly way to do the calculation vs CO2 sequestration tech would only be built where you could get very cheap and low CO2 energy.
Generally the idea is convert to cheaper and cleaner energy AND THEN focus on CO2 removal as well, not build CO2 removal powered by a coal power plant.
As long as we can keep the price trending down direct CO2 removal has SOME potential and shouldn't be overlooked, but we may need larger scale riskier biological based CO2 sequestration boosts as well. Doing nothing is still biological sequestration into the oceans, acidification and potential major collapse of ocean food chains... so it's worth trying to push the tech forward.
CO2 removal will always be needed on Earth because CO2 levels are not naturally stable and modern humanity can't survive the natural cycles of +10 and -10 degree changes that natural life survived. CO2 might be a convenient way to control Earth's temps long term. We are clearly great at adding it to the atmosphere, it only makes sense to keep researching how to remove it.
Maybe it won't pay off for 50 years, but that's still how technology and research works, it's not all short term rewards and it's not mostly success stories, it's far more like banging out every possibility until you find the one that works.
DrewsBag t1_ixcsn5n wrote
In scenarios where you are taking CO2 from flue gas, rather than atmospheric concentrations, it takes somewhere around 30% of the energy generated. Here is the fun part though, if you can capture waste heat from the combustion process to power the ccs equipment, it’s a really good deal.
dontpet t1_ixcsvwg wrote
A very high renewables grid is going to have an awful lot of power to use for other things, when in surplus. Tony Seba refers to that as super power.
We will be producing at 3 or 4 times the standard grid requirements at times. Some will go into storage, but not much. Then hydrogen production.
But put a good price on carbon and we will have lots of non carbon based surplus energy to tame climate change. I think where we put it will be more the question.
kidicarus89 t1_ixdkj7w wrote
A lot of that power could go to air scrubbing for cleaner air in urban areas as well, which could save thousands of lives globally.
arglarg t1_ixcub1a wrote
Even if the energy used for carbon capture is carbon neutral, that energy would be better used to replace fossil fuel energy.
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