For items attached to the UPS, I just monitor UPS load from NUTs.
For everything else not on a UPS (secondary PSUs from servers, monitors, and non-critical hardware), I use a mixture of HS110 and P110 TP-Link smart plugs. I had some issues with them becoming unresponsive though and the project to monitor HS110s is no longer updated and I don’t have the time to update it myself.
Especially having REMOTE users.
I was super grateful to past me for having bought systems with Bypass NICs. My parents, my in-laws, and my wife and I live on 3 separate continents.
Every once in a while, I’ll have a brain fart and do something stupid and kill some part of the network at their homes from the other side of the world (e.g. a failed proxmox upgrade that hosts OPNsense and Pihole).
With bypass NICs, just have them unplug the server and hit reset on their router and boom, back to factory settings and I’ll just fix it next time I visit.
I know the feeling. 0.44€ in Ireland as well. I use about 500W continuously which is probably around €150/month (we pay lower rates at night for 7 hours). This is a far cry from two years ago when I was running 800-900W at 0.17€/kWh