It is the question. You need to break up the CO2 molecule and reconstitute it as gasoline. That will take more energy than the gasoline had initially. So you have a process where you take say solar energy and convert it into gasoline chemical bonds. Great, what is your efficiency of this process? Because if it is close to 100%, great. But chances are it is much closer to 0, at which point you’d be better off just using that electricity for something else.
True, many people don't realize this. But carbon capture solutions don't necessarily need to be efficient - we are not doing it to make more energy, we are doing it to clean up the many decades of mess we already made in the atmosphere. So yes, we will have to spend energy, to clean that up, naturally. The most important part is that none of these solutions is exclusive and shouldn't be pictured as exclusive. We need to offset fossil fuels, lower our energy use, and suck CO2 from the atmosphere. All three of them.
Solar panels take energy to produce, transport, and install. Mining the lithium needed to produce them is pretty harmful to the environment. Other parts of the process are pretty bad too. If your efficiency is too low, if you install a gigawatt power plant and produce a half gallon of gasoline a month, you will take way too long to get an emissions ROI. Just recapturing CO2 requires less energy than recapturing and reconstituting it as gasoline. Sure you can sell the gasoline and maybe make some $$ but will that actually in the end be a net negative for the atmospheric CO2? The answer will 100% depend on efficiency.
