The UK has in the past couple of decades massively expanded its wind production, somewhat expanded its solar, and not quite completed one nuclear plant. Coal is almost entirely phased out, its use is zero most days.

(gridwatch is currently broken but you can see that we're now gas-with-some-renewables if you look back a few days: https://www.gridwatch.templar.co.uk/ )

The key to getting this to work in other countries is to exclude the coal extractors from the political process.