[JonChesterfield]

Calculate it. You'll have kW/hr costs for electricity which depend on where you are and can ballpark power based on fraction of the time it's running and the components in it.

My standard dev machine is ~1kW flat out, ~500W most of the time, probably 100W idle. Runs for about eight hours a day. Say 500W is the average, suggests 4kW/hr a day. That's about $2 a day in the UK.

(those power numbers are relatively high - it's an elderly threadripper with two GPUs)

[bee_rider]

I think that 500W average is the tricky bit. When web browsing for example, my laptop (linux+intel) seems to spend 99% of the time in the C1 halt state, according to i7z.