alt Hacker NewsYes, those are easier to store, but more expensive and less efficient to generate.
The question is the same as for hydrogen: If it's easy, cheap, and safe to generate, store, and convert back into electricity, why isn't it already being done on a large, commercial scale? The answer is invariably that it's either not easy to scale, too expensive (in terms of upfront costs, maintainance costs, or inefficiencies), or too unsafe, at least today.
With rapidly dropping PV prices it just gets cheaper - this is only a relatively recent thing; the projects that exist to exand production are barely complete yet .. capital plant takes time to build.
Fortescue only piloted athe the world's first ammonia dual-fuel vessel late last year, give them time to bed that in and advance.