Hydrogen is difficult to store and transport safely, as it has to be highly compressed to get a useful amount into a fuel tank, and is obviously highly flammabl

Hydrogen is difficult to store and transport safely, as it has to be highly compressed to get a useful amount into a fuel tank, and is obviously highly flammable. It also requires a lot of energy to extract (via electrolysis), which I imagine makes it, at best, of comparable energy efficiency to battery power. ref: http://en.wikipedia.org/wiki/Hydrogen_vehicle#Storage http://en.wikipedia.org/wiki/Hydrogen_vehicle#Storage