One complements batteries with hydrogen (burned in turbines) or long term thermal storage.
Germany has plenty of salt formations for very cheap hydrogen storage, and there are no geographical constraints on thermal storage.
Germany has plenty of salt formations for very cheap hydrogen storage, and there are no geographical constraints on thermal storage.
Given that this all-nuclear world has electrolyzers, what then prevents these from being driven by renewables (perhaps buffered short term by batteries), and the hydrogen then stored (as has been done for decades in underground storage caverns, just like natural gas is stored)? And once that is done, what prevents some of that hydrogen from then being profitably used to drive turbines when electricity prices are high? Gas turbines burning hydrogen are nearly identical to ones burning natural gas (just minor differences in the combustors) and have been available industrially for decades.
Using reasonable projections for cost (some of which have already been superseded by lower figures), we can estimate the cost of providing synthetic baseload from wind/solar/storage in Europe, using historical weather data. It comes in cheaper than nuclear.