Don’t turn off your darn computers!

Max is taking a GCC class, so I was killing time in one of the spaces and the woman who worked there was going around turning on the computers. There’s a note that asks people to turn off the computers before leaving, and it got me wondering if that was a good idea (short answer NO!)

They’re using HP EliteDesk 705 G3, so I was able to look up how many watts this computer uses when in sleep mode (1.36W), and how much it uses when turned off (.98W because it’s really not off, IT can still wake it up remotely and patch it for security reasons).

So, the difference is .38W of energy. Assuming it’s turned “off” for 18h a day that’s 6.84W per day… so it would be 146 days per KWH, so that’s around 2.4Kwh per year in savings, or 6 cents per year per computer.

This is rough-back of napkin math and doesn’t count weekends and such, so maybe it’s actually 15 cents. Unplugging completely would save almost 3 times that (45 cents per year per computer), and unplugging the monitors also would probably double that (90 cents per year per computer).

If it takes 5 minutes a day to shut down and turn on the computers then they’re spending about 16.5 hours a year turning them on and off, just to save 75 cents… but it gets better.

The IT department can probably set the computer to shut down every night and wake up every weekday morning BUT shutting down and starting up computers *does* send an extra charge into the computer, which shortens it’s life so I still wouldn’t recommend it.