Not sure why no one has done it? Not carbon neutral I guess, but paired with this and solar power it would be. Batteries are already so good is probably part of it too. But adding about 25% travel time on long drives is annoying.
Up until this point I'd imagine there was no significant advantage to creating propane vehicles unless they could be made significantly more efficient than petrol or diesel (which I'm guessing is not known to be the case)
by comparison, this discovery could make it a green-vs-brown fuel debate, at which point it would be much more valuable to invest in for vehicles
Propane combustion vehicles are common, and I'd guess a fuel cell would extract roughly 30% extra energy from the same fuel. They typically have battery efficiencies.
