[bassman9000]

which nuclear doesn't solve

Please expand. How does France handle peaks, having almost 3/4 of their electricity coming from nuclear?

[glogla]

According to [1] they also have 24 GW installed capacity of hydro and 12 GW of gas so my guess would be that?

[1]: https://www.electricitymap.org/zone/FR

[bassman9000]

That doesn't explain what the OP said. How does the 1/4 non-nuclear solve it, and the 3/4 nuclear not?