I've made this point before; at the risk of sounding like a broken record, ammonia is great if what you need is a clean fuel that can be stored indefinitely and then used as needed. But it's energy efficiency is about four times worse than Li-ion batteries. It takes about four times as much electrical energy in to get the same electrical energy out. That's offset by the fact that a load of ammonia that will deliver 100 megawatt-hours is an order of magnitude less weight than the same capacity of Li-batteries.

Bottom line: if you need to go farther than a reasonable load of batteries can take you and it's necessary to go the full distance on a single fuel load, then ammonia is a good solution. But if you can accommodate swapping battery packs enroute, batteries will be far more economical.

It's worth thinking about.