Solar-powered jet fuel (and diesel, and...)

Sounds kind of backwards, I suppose, but there is in fact research happening on creating jet fuel, and other liquid fuels, using solar energy. One of the big advantages of liquid fuels like gasoline, diesel, or jet fuel is the large amount of energy contained in a small mass—much more energy per gram than batteries. Just recently, in fact, one such research group announced that they had produced a jar of jet fuel, starting from sunlight and CO2.

Taking out the quotes and the hyperbole about revolutionizing anything, what they've done is still pretty neat: turned CO2, the low energy end state of carbon-based fuel combustion, back into usable fuel.

Because CO2 is the low energy end state, to get it back into a high energy form such as kerosene (jet fuel) or diesel, a whole lot of energy has to be put into it. In this case, the energy is solar.

Well, the energy is intended to be solar.