Both happen. It depends upon demand/output conditions at the time. France tends to use a lot of electric heaters during winter, for instance, which burns throug

Both happen. It depends upon demand/output conditions at the time. France tends to use a lot of electric heaters during winter, for instance, which burns through most of their nuclear power output (which is nearly constant throughout the year). On sunny winter days, they import extra from German renewable sources. I think during summer they might import more too. During overcast and wind-free days, Germany is probably a net importer of France's excess nuclear power.