That's a good reason not to apply this technology to smokestacks, since that would make a power plant into a power consumer. However, in some cases it's quite

That's a good reason not to apply this technology to smokestacks, since that would make a power plant into a power consumer. However, in some cases it's quite difficult to stop burning C. Long-haul jets are one example. So for those, it makes sense to make carbon-neutral liquid fuels, even though there's an energy penalty. Pull CO2 from the atmosphere, use renewables or nuclear as an energy source to turn it into fuel. CO2 emissions from steel plants might be another good application. Ideally we might be better off using clean energy sources to displace fossil plants, but that doesn't happen as fast as we'd like for all sorts of political and economic reasons. So we might as well get started now on other reductions, because it'll still help some, and we can get it scaled up by the time we've decarbonized the energy grid and want to decarbonize everything else.