We are decades away from needing this. But we need to generate ammonia without fossil fuels for fertilizer and feed stock.

Also, we need a fuel for long distance transport like ships when batteries won’t work. Ammonia will always be cheaper than synthetic fuel because no carbon doesn’t have to come from air, and it stores better than hydrogen.

There may be lots of surplus electricity in the future but there will also be a lot of demands for carbon capture, hydrogen, long term storage, and chemical processes.