China burns coal and has still had time-of-use pricing since 1999.

The price of electricity is a function of demand with respect to supply. Even if the fuel is cheap, heavy demand will cost more to supply than low demand.

https://www.climatescorecard.org/2019/02/time-of-use-electri...

Europe did not replace coal with gas. The only country that did this worth mentioning is the US.