You might be surprised about the old Skylake. If it's using a solid state drive and any unnecessary fans/peripherals are disabled, it's probably only going to u

You might be surprised about the old Skylake. If it's using a solid state drive and any unnecessary fans/peripherals are disabled, it's probably only going to use 10w or so at near idle (as a firewall would be with that chip.) Even if it uses 17W on average, the 10W difference would be $14/year at $.16/kWh electricity. Unless your electricity is significantly more expensive, it probably will never pay for itself over its useful life.