@CelloMomOnCars Why would you want to ship hydrogen long distance? Even as ammonia, it's probably easier to make it locally. Unless white hydrogen pans out, which seems unlikely. Large scale grid connections are necessary and lose very little power, and there will be surplus renewables often enough.
Of course that's assuming that we find a solution for low load factor green hydrogen; current electrolysis has difficulty below 50% load, and every time you start/stop it there's a leak into the atmosphere.
Also assuming that hydrogen is mostly used for 1) industry, 2) shipping and 3) possibly long term grid connected electricity storage. Though the last is frankly doubtful.
Both hydrogen and ammonia are a problem when leaked and produce significant pollution when burned. So burning it is at best a stop-gap; ultimately we need fuel cells. Having said that, the article claims that it's practical to filter out NOx from shipping engines; an interesting claim given this is one of the main arguments against burning hydrogen for electricity. It looks like a long term project though given the demo was only 8kW!
Long term there may be other options but both iron-air and DARPA's high-density flow batteries are under around 1200Wh/kg, which is fine for grid storage, but 1/5th the density per kg of ammonia (if I've done my sums right; ammonia is around 20MJ/kg). Although DARPA's goal is to eventually be able to use it for aircraft and tanks.