large cluster of them to do much "mining". Your exiting power panel and circuit breakers might need upgrading. Second issue is the heat they generate, which exacerbates the power problem as your cooling power will go through the roof (or if you don't cool, the equipment will fail). Third was noise. All those compute boxes and with big cooling fans running 24/7 makes it a "home business" with several major drawbacks and hurdles.

It's been a few years since I've talked with anyone doing this, but those were the real issues a while back. Maybe some changes / improvements, but I doubt much.