Partly because they still use coal, which is heavily taxed under the emissions trading scheme and partly because of the way electricity auctions work in most of Europe, namely every participant sells at the price offered by the highest bidder.
Spain opted out of this system and is now enjoying cheap wholesale electricity, which is fueling an industrial revival.
> Partly because they still use coal, which is heavily taxed under the emissions trading scheme
... and solar is heavily subsidized, which could outweigh this effect. So this doesn't explain the high energy prices.
> partly because of the way electricity auctions work in most of Europe, namely every participant sells at the price offered by the highest bidder.
This doesn't explain why Germany has so high electricity prices.