- interconnect with other regions (someone always has wind or sun or both)
- spread turbines across the entire country
- build as much PV as possible (there is plenty of space on roofs)
- combine renewables with hydro storage
- (in a few places) generate hydrogen and store for times where wind & sun are not enough. Doesn't have to be pure hydrogen, converting to methane or better yet ammonia)
There is effectively 0 sun during the winter in Finland.
Just go to https://www.fingrid.fi/en/electricity-market-information/sol... and look at last year Decemenber or January.
> - interconnect with other regions (someone always has wind or sun or both)
Until they don't because the country 10x your size with massive heavy industry on the other side of that country you want to import from wants to buy all of it.
PV produces absolutely nothing when electricity is most used and absolutely necessary (midwinter).
Hydro capacity in Finland is at its maximum potential and even now cannot make up for times when wind is producing close to nothing.
Also, all these workarounds cost money -- some of them, lots of it. For TVO, Olkiluoto 3 costs roughly 5B euros for 1.6GW of nuclear.
If you are going to interconnect with solar and wind you have to spread it across multiple countries. Of course we are seeing how well that worked out with gas and Russia right now.