[pyrale]

> nuclear often has to shut down in the summer either because rivers don't carry enough water or are so hot that feeding warm cooling water back into them endangers fish).

I don't believe this has much impact on Germany's export patterns: in fact, summer is usually the time scheduled maintenance is planned in France, because electricity usage is much lower during summer than during winter. So there's still a lot of wiggle room before France ends up being forced to import in the summer because of that phenomenon.

The main driver for import/export patterns are different consumer patterns (not all countries have the same daily load curve - for instance, France and Spain both benefit a lot from trading because France's peak use time is an hour ahead of Spain's) and renewables availability.