For those looking to get an objective understanding of this decision I found this article useful[0]. The gist of it is that this is more about preventing future rules to be put in place rather than changing anything that the EPA is actively enforcing. Essentially the EPA cannot force the shut-down of coal fired power plants (or other high emission energy sources) using the Clean Air Act.

As someone very pro renewable energy obviously I would prefer a different outcome, but the good news is that these types of power sources are just plain uneconomical these days, so their shutdown is going to happen anyways. Perhaps renewables won't have as many regulatory assists as we hoped, but the good news is that they can stand on their own, and the clean power industry keeps building better systems then capitalism will take care of the transition for us.

[0] https://reason.com/volokh/2022/06/30/supreme-court-rejects-b...