Use of hydrogen on a train is a bit stupid though - trains are the the one mobile power use where there's no real benefit to being able to dump the ash into the

Use of hydrogen on a train is a bit stupid though - trains are the the one mobile power use where there's no real benefit to being able to dump the ash into the environment. You may as well just supply good primary battery reactants, such as zinc, or sodium and sulfur, which can be efficiently be recharged somewhere away from the train.