A hydrogen fuel cell car is basically an electric car + a hydrogen fuel cell, because: 1) The energy from the fuel cell has to be temporarily buffered in a bat

A hydrogen fuel cell car is basically an electric car + a hydrogen fuel cell, because: 1) The energy from the fuel cell has to be temporarily buffered in a battery, which is capable of finely modulating the power output needed for driving vs a fuel cell. 2) To absorb energy from regenerative braking. Hydrogen fuel for automotive applications don't work in reverse (convert energy back to H2) Granted, this battery in a fuel cell vehicle can be smaller than in a pure EV, but now you have 2 very expensive energy management systems in the car, which makes the whole thing very expensive.