We're a long way away from consuming so much energy we thermodynamically scorch the Earth, right?
It seems like they want to know if you can be mostly carbon neutral and generate existing fuels.
If that's the case, then if you have access to a cheap form of renewable energy -- huge amounts of geothermal, tidal, or solar -- you could generate a ton of something-like-gasoline, reduce carbon, and come out nearly neutral when re-burning it.
Theoretically, you can profit if the renewable source of energy is cheaper than the cost of generating and distributing the fuels.
I'm skeptical this is possible. But if it is, I'm optimistic it will actually happen.
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.
Hydrocarbons are better energy stores than batteries. If we can “charge your car” by pumping hydrocarbons into it, that is better than lugging around heavy batteries (maybe.) so, in a way, co2 -> gasoline via solar power (or nuke) is an overall win.
I personally doubt the energy cost for the conversion is so low that it makes sense, but would like to see that demonstrated. Then you are still burning hydrocarbons, which is a big health problem.
