> Solar panels in Northern Europe provide plenty of energy.

For ~9 months of the year. For winter you need some other form of production that you can turn on at demand.

For example a panel in Helsinki produces less than 1% of its nominal output in the darkest months of winter.

edit: Just go and look at https://www.fingrid.fi/en/electricity-market-information/sol... if you check December of 2021 you can see that the avg output was ~2MWh/h with solar 395MW of capacity installed at the end of 2021.