Batteries are too heavy for many applications (including, arguably, cars).
That doesn’t make hydrogen the only solution but it is at least a currently available solution. I posted a link about why the Orkneys (population 23k) are producing hydrogen and switching much of their transport to it: they have so much wind the UK (population 70m) national grid can’t take all the power they generate from it.
Batteries are too heavy for many applications (including, arguably, cars).
That doesn’t make hydrogen the only solution but it is at least a currently available solution. I posted a link about why the Orkneys (population 23k) are producing hydrogen and switching much of their transport to it: they have so much wind the UK (population 70m) national grid can’t take all the power they generate from it.