My co-worker, recently loaned me an energy monitor-logger. This device will log the electrical usage of a circuit. Whether it be one item or multiple items on a circuit, no matter. The monitor stores it's readings into internal memory. It then estimates a monthly electrical cost for the use of the circuit based on the readings in memory. The unit connects to the computer using USB, and the data can be downloaded from the device to analyse the usage of the circuit. So what does a computer use on electricity. Well it'll depend on your computer. I think I have a run of the mill set up. (well it's a dated set up, but still)
- Generic Tower
- AMD Palimino XP2600+ with 1.25GB RAM (DDR400)
- 120GB and 80GB hard drives.
- DVD Burner
- Soundblaster Audigy
- Ati All-In-Wonder Radeon 7500
- 19 Inch Flat front CRT Monitor.
- Wifi Hub
- Cable Modem
- 5.1 Surround speaker system
- InkJet Printer
So What does this set up consume on electricity? While the computer is running; with average usage; My computer setup draws between 960 - 1100 Watts of power. Average usage means surfin' the web. Listening to mp3s while doing it and maybe doing some flickr uploads at the same time.
At 6.5 cents per killowatt hour (and that's a pretty good rate), if I was running the computer 24/7 I'd be looking at ~$40.00 - $50.00 per month on electricity. Now a breakdown showed that around 300 watts were consumed by my monitor alone. So I could probably save myself somewhere close to 6 bucks a month by buying an LCD monitor, assuming it was running 24/7. The LCD monitor would pay for itself in a couple years. A good way to justify an upgrade, wouldn't you say?
How about idle time? My computer, when sitting unattended; hard drives not spinning, monitor in powersave mode, speakers off and printer turned off, still consumed over 500 watts of power, or about $20.00 a month. Kids, that's $240.00 per year.
Lets assume that you're not using a gaming system, and that an $800 computer does the job for you, and lets assume that you use your computer for 5 hours a day. By shutting off your computer when not in use, you could save the equivalent of a new computer in under 4 years. That's assuming you're paying 6.5 cents per kilowatt hour.
If you want to look at it another way..... If you could save $200.00 per year. If you earn $10.00 an hour, and are in a15% tax bracket, you'd have to work an extra 23.5 hours per year to pay for your computer running idle while you're not using it.
So... is it better for the computer to be turned off? I don't know, but I know what's better for my wallet... and the savings...well they'll get absorbed someplace into my budget, but at least when the computer does need replacing, I can justify it that much more easily.