Now this is some tech to get excited about... Solar thermochemical reactors that can make hydrocarbon-based fuels out of just solar energy and air! This tech could radically change the impact of air travel, since the amount of CO2 produced by burning the fuel cannot exceed that which was captured to make the fuel (carbon neutral). https://spectrum.ieee.org/energywise/aerospace/aviation/rooftop-solar-refinery-produces-carbonneutral-fuels