[Heston]

Hydrogen's volumetric energy density is about as good as lithium-ion. The cost of replacing a hydrogen tank vs a lithium battery is absolutely massive. You also aren't considering the energy density lost in cold weather for batteries.

[Retric]

Almost the same in the short term requires you to liquify hydrogen and then use it immediately. Because the energy density rapidly goes to zero for any application with a moderately sized tank. On top of which you need a cryogenic tank, costing you even more volume.

Liquifying hydrogen also costs you another ~10-13 kWh /kg where Hydrogen only contains 33kWh if you want heat, but more like 10-15kWh/kg if you want to do useful work. So you’re roughly paying double the energy for the same amount of energy stored.