Except possibly when energy prices are negative due to wind and solar intermittency - although that is also a signal that you need more storage in the grid, additional storage may not be economic for some reason.
> The green hydrogen will be combined with carbon dioxide captured from the cement plant to produce synthetic methanol, which would then be refined into carbon-neutral synthetic kerosene (ie, aviation fuel), for use at the nearby Hamburg airport. The airport is hoping that 5% of all fuel used there will be carbon-neutral by 2025.
[1] https://www.rechargenews.com/transition/offshore-wind-to-pow...
For example, batteries exceed 90% efficiency for storage, but they are only cost effective for day-to-day storage. (Charge when the sun is out, discharge at night.)
In contrast, charge during long summer days, and discharge during shorter winter days will probably be lower efficiency at first. For example, generating hydrogen by electrolysis is about 75% efficient (https://en.wikipedia.org/wiki/Hydrogen_production#Electrolys...), and then pressurizing it will also consume energy.
This means it may be more cost efficient to extract CO2 from the atmosphere as "storage" and then burn natural gas... At least until we find a better way to store energy than hydrogen!