The idea would be (for me at least, I am not neutral in this) to marginalise the coal and oil and gas generation to make it the most expensive form.

If you live in Poland, or Victoria (Australia) you have unlimited brown coal, which burns sulphurously filthy bad smoke, its the worst possible energy source we have right now but its the cheapest. It has already been seen to displace high quality low-ash black coal, because thats worth money in China and India for export. So I get your message: cheap beats clean.

If you legislate for the cost of dirty cheap power, then storage losses are a lot more tenable, compared to the remediation cost. BTW economists actually do cost the deaths per gigawatt. Dirty Coal has a really high death rate both mining it, and burning it. Kids die of Asthma at far higher rates, in economies which burn coal for power. The economic costs of killing children, quite apart from the social costs, are huge. Actuarially speaking, you don't want to do this because you alienate future income from those kids grown up, earning money. Its a third-party damage problem which makes it easy for the brown coal generator to ignore, but when the kids of the coal miners and power station workers die, (and that happens) it gets a bit more direct.

Victoria had underground brown coal fires burning for YEARS.