I can only see one real path to H2 being practical in the US, and that is if it is generated using very cheap, off peak electricity. The only source I have seen where the numbers (in terms of both $ and pollution) come together is (don t yell) Nuclear.
Without getting into whether or not this is a good idea or not, it certainly has its pros and cons, both technically and politically.
It would be much easier, safer, and more efficient, IMHO, to use off peak power to recharge EV batteries at night, than produce H2 and build that infrastructure. At least here in CA, with grid electric rates running $ 0.20 or more when you go over the limits, EV vehicles from grid electricity are a no - go. Currently, the home user price for peak / off peak are the same.
BTW, I have experience with H2, and safety is not one of its high points. Gasoline produces some impressive fires, but H2 produces some really good bangs.
Battery technology still has a way to go as well from a capacity / safety perspective. I used to be pretty gung ho about using a battery pack made up of a few hundred 18650s. I now realize some of the very real challenges that this technology presents to companies that are sued regularly by their customers.