A company in England, Air Fuel Synthesis, has demonstrated a method of making a liquid hydrocarbon fuel from nothing more than air. Well, more specifically, they say the process:
“captures carbon dioxide and water from the air, electrolyzes the water to make hydrogen, and reacts the carbon dioxide and hydrogen together to make hydrocarbon fuels”
Naturally, they believe it is a scalable process but is so far confined to laboratory volumes – they’ve produced five liters since August, which is fantastic but they have a ways to go. What’s key here, too, is how much energy is consumed in this process, something that so far I can’t find details of. If powered by solar or wind, though, a process like this could theoretically be nearly carbon neutral, yet still provide fuel to power cars and trucks. Or, if coupled with a utility-scale solar panel installation, some excess solar energy could be funneled to this process during the day, producing fuel which can power generators during the night when the panels aren’t producing.