re: 2NH3 + 2O2 -> N2O + 3H20
Hi Jacob
Don't be daft!
They're cracking the ammonia for the hydrogen and putting that through a fuel cell - only exhaust is nitrogen and water.
And it's ammonia IN salt, not ammonia salts.
But you're right on the money about where to get the stuff - from some energy consuming process. It's only renewable if hooked up to a renewable source. It acts as an energy storage device without energy-munching compression and cooling or excessive heating to liberate hydrogen from hydrides.
Ideally we should have a "hydrogen sponge" for storage, but no one has one on offer yet.
Adam