It's going to be produced in large quantities in the Australian desert using wind and solar. Close to ports so it can be shipped out in the form of ammonia, but too far from the eastern population centres to "just use the electricity for the grid!".

We currently have so much excess green energy in these areas that it's being used to mine cryptocurrencies, the plan is to use this excess for something less wasteful like electrolysis.

Storage and transport issues were figured out a long time ago, we've already shipped to Japan in hydrogen form, as ammonia it'll be even easier