I take more than nitpick exception to the claims of the lone ZEMU Arrow train as "US' first zero-emission train."

Electric trains (i.e. zero-operating-emission; electric transportation emissions and overall impacts always depend on how clean the power supply is, and where it is) are nothing new, running under wire or on 3rd rail; they aren't even particularly uncommon in the US if you include light- and heavy-rail transit. H2 looks like an interesting way to provide ZEMU in certain niches, such as where there are simply no wires/3rd rail available for charging on-route (overhead wires are very expensive to build). Batteries are probably *almost* good enough for prime time in other niches, such as when wires or 3rd rail are available someplace on-route or at a terminal for recharging, but service to off-wire locations not too far away is the point. I'm more than happy to welcome HMUs to the party; "all of the above" is a good way to look at it. I just don't think they should be considered the only ones at the party.