It's not a matter of efficiency but a matter of scalability: hydrogen generated by hydrolysis demand so much energy that we can't produce it on the needed scale

It's not a matter of efficiency but a matter of scalability: hydrogen generated by hydrolysis demand so much energy that we can't produce it on the needed scale, no matter how much it can cost. Methane extraction is absurdly costly, transport and storage are no less absurd BUT we can do it on a needed scale. That's the sole thing that matter. Similar if for hydro: mountain hydro is fantastic, we MUST develop it as much as possible, but it demand mountains and water. For some part of the world it's ok, they are there both in needed quantity essentially all the year, for some other they are not. You can power Norway on hydro with little nuclear backup, you can't power Mongolia even if Mongolia have very little needs compared. Similarly we can imaging electric commercial trains that only run on p.v. surplus, for all non-perishable goods that might be ok if well designed on scale. We probably can design that on scale in many, many areas of the world. We can't to the same for ships, for plane, for cars. We can't do that for perishable goods of passengers transits.