Earlier quoted context omitted.
> Hydrogen is such a terrible idea it was never getting off the ground. It's coming from Toyota because Toyota can't wrap its head around not making engines. Ironically, the place hydrogen might work is airplanes where the energy density of batteries doesn't work.
We're actually not that far off. Right now, liquid fuels have about 10x the energy density of batteries. Which absolutely kills it for anything outside of extreme short hop flights. But electric engines are about 3x more efficient than liquid fuel engines. So now we're only 3x-4x of a direct replacement. That means we are not hugely far off. Boeing's next major plane won't run on batteries, but the one afterwards def…
However, as others have pointed out, the battery-powered plane doesn't get lighter as it burns fuel.