The economic realities of electric car?

[iancampbell]

I like fuel cells because they utilise oxygen from the atmosphere; this allows them (in theory) to have a greater energy density than batteries.
They don't deliver this energy very quickly, though, which means that capacitors (and supercapacitors) are better if you need a lot of power quickly.

Yup. However, I don't see any reason why a supercapacitor bank shouldn't be used in combination with another type of energy storage/generation, maybe fuel cells, for times when short bursts of power are needed.

Another reason for having some sort of energy storage on board is to allow regenerative braking to be used. Braking wastes all the energy used to accelerate the vehicle; regenerative braking allows at least some of this energy to be recovered.

As for the comparison between a tank of fuel and a battery bank: A damaged battery bank is quite likely to get hot without any interaction with the outside, simply by shortcircuiting - and current designs use lithium, which is highly flammable in air to say the least. Whereas something like methanol doesn't just spontaneously combust and water-miscible fuels (including methanol) are easy to get rid of with simple water. Try stopping a lithium battery fire with water!