I also doubt they would want to regulate themselves out of existence nor do they have the lobbying clout to get subsidies... but they might need to suck up to govt/banks/etc in some way and buy some solar panels from Elon. Again, a mighty ironic place for Bitcoin miners to be and mostly because some wall street brats pretend to be our friends while tweeting stupid shit.
The problem with solar is that it is a heavy up-front investment which you only eventually catch up with after many years. For miners, they'd rather be putting that money into mining equipment or could straight-out buy Bitcoin.
Put up a couple of panels for show, call it the primary energy source, get the other 99% from the grid and call it a backup because it's sometimes cloudy. I'm sure I'm just scratching the surface here of what corporate weasels can come up with to call themselves "green". Especially when there is a petulant billionaire tweeting nonsense and interfering with their business.