[RandomLensman]

As we can store fossil fuels for weeks of demand, we can store the required energy in chemical form, no? Germany has huge natural gas storage, for ezample.

[deepsummer]

If you mean hydrogen, this video explains the issues better than I can: https://www.youtube.com/watch?v=Zklo4Z1SqkE

[RandomLensman]

Doesn't need to be hydrogen - plenty of possible substances that could be used as storage (might not even need to be gaseous for some applications).