Most likely not solar since there’s almost no solar during the winter months. Sun comes up at 0900 and goes down at 1500 in the south. In the north it’s worse.

It's currently noon in Finland and solar accounts for 6 MW in the grid. That's about 0.05% of the total production. Nuclear is 3863 MW (~31%) and wind is 6281 MW (~50%).

What might be plentiful is wind, especially during the nights.