> If you're worried about power consumption from a cost perspective, it's going to take a long time to break even from the cost of new hardware, even for a cheap pi.
That depends a lot on where you live. In Germany, prices scratch 0.3€/kWh. A new Pi sets you back 60€ [0]. Assuming you save 20W and it's on 24/7, you'll break even in just above a year[1].
[0] I know it's marketed as cheaper, but you never get it for 35€ and then you still need cables and an SD card.
Sure, and it never hurts to do the math for your particular situation. Being in California I'm probably paying about the same as you per kWh. I do think 20W delta is rather optimistic, since the last time I checked a decade ago, laptops only consume 10-15W at idle, and pi's likely consume at least a few watts themselves. Laptop hardware is generally pretty good about reliably suspending to ram and resuming.
My general point is that there's a lot of externalized costs to consider depending on what you're trying to optimize for. For example, I live in a somewhat chilly area most of the year, and part of my home is electrically heated rather than by natural gas. I don't particularly care how efficient any electronics are in that part of the house (when I'm using them) because that electricity is converted into useful heat just as well as a space heater would do it.
That depends a lot on where you live. In Germany, prices scratch 0.3€/kWh. A new Pi sets you back 60€ [0]. Assuming you save 20W and it's on 24/7, you'll break even in just above a year[1].
[0] I know it's marketed as cheaper, but you never get it for 35€ and then you still need cables and an SD card.
[1] you save 52.50€ per year