A lot of mining is done close to hydro dams, this power was in some cases waste power that would be unused. So it is swings and roundabouts, I don't think any n

A lot of mining is done close to hydro dams, this power was in some cases waste power that would be unused. So it is swings and roundabouts, I don't think any new coal power stations are being built to mine bitcoin but bitcoin miners have taken advantage of excess electricity production to site their mines where power is cheapest.