What if power consumption is taken into account? Are there any devices in that category that are ok to leave on 24/7 ?

I have a somewhat bigger machine that hosts my homelab, an HP 800 G2 SFF. It takes "normal" components, so can ben modified. The only custom thing is the PSU, but the standard one is good enough for my needs. Bonus points for not requiring an external power adaptor.

It has an i5-6500, 32 GB RAM (16 + 2x8 DIMMs), 2 SATA SSDs and a 2x10Gb Connect-X3. It runs 24/7 hosting OpnSense and HomeAssistant on top of KVM (Arch Linux Hardened – didn't do anything specific to lower the power draw). Sometimes other stuff, but not right now.

I haven't measured it with this specific nic, but before it had a 4x1Gb i350. With all ports up, all VMs running but not doing much, some power meter I got off Amazon said it pulled a little over 14W. The peak was around 40 when booting up.

Electricity costs 0.22 €/kWh here. The machine itself cost me 0 (they were going to throw it out at work), 35 for the nic and maybe 50 for the RAM. It would take multiple years to break even by buying one of these small machines. My plan is to wait out until they start having 10 Gb nics and this machine won't be able to keep up anymore.

Quick search online tells me ~5W for the Dell Wyse 5070, which does not sound unrealistic as I have similar boxes that draw ~10W. So, 32 to 62kWh per year and then we have ~USD 6.5 to 13 per year assuming 20 cents per kWh which another online search told me was reasonably realistic for the US.

Tangent, but it's always crazy to hear what other countries pay per kWh compared to the 0.4€/kWh in Germany.

Yeah, and Germany is expensive compared to the Nordics. 6.35 c/kWh right now in Finland, 2.54 c/kWh average over the last 30 days.

(clarification: that's euro cent, so 0.0635€ etc)

Yeah, that's pretty low. Even Denmark, right north of Germany, is paying 1/4 of what we pay.

Bay area, California: $0.61 base, $0.80 from 16:00 to 21:00.

Don't worry, there are some places in the USA that are even worse than that, like san diego, san francisco and hawaii

And in Iceland the average is around 0.07€/kWh.

Yea, I own Wyse 5070 extended, and measured around 5W from the wall when nothing attached to the PCIE slot.