Ballard Power Systems, for one, has been delivering hydrogen fuel cells for about the last three decades, before Rio and when the concern was peak oil. Nothing new there.
Any large scale industrial gaseous fuel can be converted to hydrogen, so nothing new there either.
Industrial electrolysis of water is 70 to 80% efficient at the electrode, not including rectification and pre-treatment [ typical potable water specs in the cell would be the end of it ]. If the hydrogen is stored and burned on site as a closed loop, compression efficiency is not a great deal, so maybe an additional typical 10% all handling and thermal loss to produce electricity. There are existing technologies which store energy far more efficiently. Sure they cost, but hydrogen plants are full of even more costly alloys to deal with hydrogen embrittlement. Most metals soak up hydrogen where it disrupts the integrity of the metallurgy and can result in catastrophic loss of containment.
Liquify the hydrogen for transport? Now we are talking serious inefficiencies. Getting down to the lower kelvins means 40% efficient is doing great. Add it all up, and grid to EV looks infinitely better.
I always feel like such a curmudgeon when hydrogen comes up, but it comes out of actually having worked with the stuff in industry. The idea of water coming out of the tailpipe is appealing; but the very stability of water is the challenge, why electrolysis is so energy expensive, and why hydrogen is so volatile.
Hydrogen will likely find more applications, which is fine. My biggest objection is that the notion that hydrogen can square energy requirements with a carbon free future will be a green phantasm which deflects from the most effective base line solution, which is an expansive build out of nuclear power.
Key takeaway from the video.
I think to go big, to really get toward a national hydrogen network, the government incentives and government support and partnership are critical.
Same old pitch from a vested interest. Could hydrogen be the clean fuel of the future? Perhaps, but is it more likely that past is prologue.