[ephbit]

Hydrogen is relatively inconventient/difficult to handle except when transported via pipeline.

There appear to be no dense long range pipeline networks (for hydrogen) connecting multiple countries (yet).

Pipeline networks for natural gas aren't designed to safely transport pure (or high concentrations of) hydrogen, so over a certain concentration hydrogen would have to be converted into synthetic natural gas. The latter conversion appears to not yet be deployed at very large scales.

Seems to me that the reason why there is no large scale hydrogen generation yet (though there are medium-large/industrial scale projects now), is simply that until now large scale wasn't economically feasible. With hydrogen strategies and more pressure from a price on CO2 on their way we'll definitely see more of it soon.

[pfdietz]

For grid storage, hydrogen would not need to be transported at all (although the option to do so is there if it's favorable). It could be made above the storage caverns, pumped into them, then extracted and consumed there.