Would not recommend under clocking. Buy a kill-a-watt measure your idle that’s your general power usage. A cpu that has a low TDP and newest generation is going to be the most efficient. After that it’s each item you add adds more usage at idle which is going to be most of your time. Transcoding efficiency doesn’t matter much since you are likely not transcoding when you aren’t watching videos. Have an appropriately sized power supply that platinum or gold certified, usually the extra cost will be justified by power bill usage over a year or 2.

For example my older gen server, a dell r720xd, sits about 120-130 watt but with 9 spinning disk drives each about 5w per hour it sits around 200w per hour. This does go higher when watching videos but is far from the average. 200w per is roughly $15-20 per month where I am located.

I hope this helps.

It also generates waste water that has to be sent to a treatment plant they can’t dump it back into the environment because it’s so concentrated with minerals

It’s been reasonably active here definitely not reddit in it’s prime, I haven’t found it worthwhile to self host lemmy but others may chime in that do. I’ve got a few other things I’m hosting on my Dell r720xd matrix, jellyfin, wireguard, next cloud, gonic and other minor things.

How do you check?