oh, and I remember one other thing. Even though the mirai drivers were getting free fuel (at the beginning), I think H2 was like the equivalent of $17/gallon marked on the pump.
A drop in temperature will be (more or less) proportional to a drop in pressure. See https://en.wikipedia.org/wiki/Ideal_gas_law
The nice case is adiabatic expansion, and at least the sign of the temperature change has the decency to behave the way one would expect:
https://en.m.wikipedia.org/wiki/Adiabatic_process
The more realistic case for a gas station is Joule-Thomson expansion, and it thoroughly defies basic intuition: https://en.m.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
The reason I bought a Mirai is because I wanted to go zero-emissions but I’m an apartment dweller with no EV charging options. The Mirai is the best vehicle I’ve driven in terms of its features and comfort. However, once my fuel card ran low, I ended up getting a gas-powered car since $36/kg is prohibitively expensive for me to pay out of pocket.
I hope the hydrogen situation improves, since not everybody has convenient access to an EV charger, not to mention the cost of electricity in PG&E territory.