Electric motors and batteries are very efficient, and therefore extremely cheap to operate. Biofuels make sense I think for aviation because you need that ener

Electric motors and batteries are very efficient, and therefore extremely cheap to operate. Biofuels make sense I think for aviation because you need that energy density to get a usable range, but the fuel is likely to be expensive for a long time. If you can figure out how to make liquid fuel for about fifty cents a gallon or so, it might be competitive with electricity for car use. I don't know what the energy requirements are for modern batteries, but I expect it varies a lot depending on battery chemistry. Battery sizes vary a lot, too.