Solarpunk technology

Okay, but this application only requires 1.9MWh on board. That would be about 57kg of hydrogen. The required capacity would actually be less since the hydrogen refuel time should be significantly less than recharging a battery. Anyway, I just doubt very much that 11,900kg storage vessels and fuel cell would be required. There's simply less dead weight in a hydrogen vehicle as well as better performance and less externalities associated with battery production and disposal/recycling.

As for the efficiency of hydrogen production and delivery, it shouldn't matter. We need to produce it anyway for emissions free steel and fertilizer production. The real problem is that we don't have enough emissions free energy production, which isn't one that battery vehicles or storage facilities solve. The current paradigm is one of deficit in order to create a market and I think battery storage unfortunately facilitates that. Instead, we need to build out capacity so that there's almost always a surplus of electricity with the extra getting diverted to hydrogen production. It should be rare that the process is reversed to turn hydrogen back into electricity for the grid. That hydrogen is currently too expensive is the result of bad policy, which BEVs just reinforce.