That minimum is, at least for Germany, nowhere near 30% of installed capacity. It's just a few percent. And that's how 40GW are in reality just about one or two GW of guaranteed power. The rest will get burned off or you need a very flexible alternative energy source.
A year ago I would have said that to be gas. Seemed like a good fit for wind. Had Germany converted all its coal and nuclear plants to wind/solar + gas, however, the current situation would be more dire than it already is today.
The most reliable way seems to be to accompany wind with storage. A lot of storage. But that's a long term solution. Short to mid term you need alternative reliable sources. If you don't want to go with coal, nuclear is the only remaining option. So I can't blame the Swedes for going that way.
We're talking about Sweden that has high amounts of hydro power available for storage.
https://www.powermag.com/frances-nuclear-storm-many-power-pl...
It’s typically 30% for wind power. That’s still 12GW.
40 billion should be enough for one Hinkley point C type reactor, having 3 GW capacity. Mind you that especially one nuclear reactor is not reliable either having to shut down for maintenance. France for example only gets a load factor of 77% out of their nuclear reactors.