It's probably going to be a carrot and stick issue in the EU. States have to do X to get EU funds or else trigger an infridgement procedure, get fined and get cut off from EU funds. At least that's how it works now. They're also careful to steadily increase the price of gas or electricity with a few percent every year since nobody wants mobs breaking storefronts and setting things on fire. Coal will probably be the first to go if everything goes smoothly and Poland is in a lot of trouble if they don't build at least 3 or 4 nuclear reactors.