Seasonal leveling doesn't require transport -- make the hydrogen above the storage caverns.
Green hydrogen certainly is more expensive than hydrogen derived from fossil fuels, but if we are imagining a 100% RE grid, that hydrogen isn't available. It does make sense to burn natural gas directly instead of burning green hydrogen as long as the CO2 charge isn't high enough to rule out use of natural gas. This is why we're not yet seeing a large green hydrogen role out in Europe.
The interesting question is whether fossil hydrogen with CO2 sequestration is acceptable. It may be preferable to green hydrogen, depending on things like methane leakage.
Green hydrogen certainly is more expensive than hydrogen derived from fossil fuels, but if we are imagining a 100% RE grid, that hydrogen isn't available. It does make sense to burn natural gas directly instead of burning green hydrogen as long as the CO2 charge isn't high enough to rule out use of natural gas. This is why we're not yet seeing a large green hydrogen role out in Europe.
The interesting question is whether fossil hydrogen with CO2 sequestration is acceptable. It may be preferable to green hydrogen, depending on things like methane leakage.