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Power consumption of various household items…

I recently came across my old Kill-A-Watt device, and decided to see how much juice a few items in the house pulled either when on (and not in use), or when completely shut off (but plugged in).

TV-related stuff (all shut off but plugged in):

  • An old Admiral VCR – 7 WATTS
  • An old RCA ColorTrak 27″ color TV – < 1 WATT
  • A Yamaha HTR-5730 receiver – < 1 WATT
  • A Sony DVP-NS718H DVD Player – < 1 WATT

The VCR pulls a stunningly high 7 WATTS just by being plugged in. Combined, the other 3 totaled 1 watt of power consumption on the meter. The VCR alone uses 61.32kwh per year. Granted, this is an old model. I’d hope that newer models would be more efficient.

Typical Computers (on but at idle):

  • Desktop (Intel Dual Core E2140, Radeon HD 4850, standard accessories) – 95 Watts at idle, not including monitor
  • Desktop (Intel i3, Nvidia 8400GS, 3 hard drives, standard accessories) – 77 Watts at idle, not including monitor
  • iMac 7,1 (Core2Duo, ATI HD 2600) – 64 Watts at idle with the screen on

I wasn’t really fair to the iMac here, because the screen was on. You’d be looking at considerably less power consumption when the display turns off after inactivity, and it’s the reading I should have taken.

What you can take from this though is that leaving the computer on 24/7 isn’t a great idea. If you use the 2nd machine as a guideline, you’re looking at 674kwh per year. Every computer nowadays comes with sleep of some sort which should drop consumption to well below 10 watts – always use it.

If you absolutely need to run a computer full-time (if it’s serving files/music/etc for example), you might want to consider putting together (or buying) a system based on the Atom. If you need something on 24/7 that you’re actually using for desktop use, I’d really suggest looking into an Apple mac mini or iMac for general desktop use. If you need a 24/7 powerhouse, then… well just do your best to research the newest processors/vidcards and find components that have a strong performance to power consumption ratio.

Other Computer Stuff (on, at idle):

  • D-LINK router (DIR-825) – 6 WATTS, 4 WATTS with wireless disabled (5 with only N or B/G enabled but not both)
  • Apple Time Capsule MC343AM/A – 11 WATTS at idle (wireless enabled)
  • HP Photosmart C7280 Color Inkjet Printer All-In-One – 4 WATTS when off but plugged in
  • HP LaserJet 1600 Color Laser Printer – 10 WATTS at idle
  • Brother HL-3070CW Color Laser Printer – 7 WATTS at idle

As far as the routers go, there aren’t any surprises here. The time capsule’s higher in power consumption, but it’s got a hard drive inside.¬†As far as the savings on wireless, if you don’t need wireless, disable it (for security reasons if nothing else), but I wouldn’t go crazy and just disable the band you don’t use in hopes of saving a watt (it’s convenient having 2 bands available when you have people over or when a neighbor’s microwave causes interference with a band, and 1 watt is a small price to pay in the grand scheme of things).

The printers were interesting. I didn’t test the inkjet in the on-but-idle stage, because it’s something that has a button on the front and can be easily turned off. However, it uses 4 watts when turned off – rather surprising. Part of that might be the power pack (which has an LED which lights up as soon as it’s plugged in). I really expected this to be close to 0.

The HP Laser is a few years old now, and consumed the most power. It’s got another issue though in that it periodically goes to full power for seemingly random reasons. It might be that the computer/drivers periodically query the thing, or it might simply go through the power cycle on a regular timed basis. The power switch in this behemoth is tucked in behind, so it’s on 24/7.

Since the Brother Laser was new I’d actually hoped for (and expected) closer to 0. It does go perfectly silent, and pops into “Sleep” mode after 5 minutes (this can be adjusted), so I was surprised that it managed 7 watts while in sleep. Fortunately, it doesn’t seem to be plagued with the same random cycle issue of the HP.

Random items on (which you’d tend to leave turned on) at idle unless otherwise indicated:

  • 12″ black fan (the kind you might use during hot summer nights) – 23 WATTS at low, 27 at medium, 32 at high
  • Old Fax/Phone Machine (on, idle) – 6 WATTS
  • Computer Speakers (cheap 2-speaker model) – < 1 WATT
  • Microwave – < 1 WATT
  • Newish Maytag Stand-up Freezer – < 1 WATT
  • Coffee Maker – 900-1000 WATTS (on)

The fan was interesting, because leaving it running when not around is about the same as leaving a standard spiral fluorescent light on.

The fax machine surprised me. It’s rarely used, perfectly silent, and all that’s lit up is a little LED. 6W seems a little high.

Speakers, Microwave, and Freezer all surprised me too, although it was in a good way (especially the freezer). All of these things read 0 on the meter, and it’s nice to see that high-power devices like the microwave and freezer are able to drop from incredibly high amounts to almost nothing. Because speakers are annoying to turn off, I was pleased to find that there’s no need.

Finally, the Coffee Maker, a Black & Decker Smartbrew, blew me away. This model doesn’t have an auto-shutoff, and I commonly keep it on throughout the day. At between 900 and 1000W, I won’t be keeping it on anymore. I’ll make the coffee and throw it in a thermos if need be. In fact, I’d be better off letting it get cold and simply heating the stuff in the microwave. Seriously, 1000W is 8760kwh per year. That’s as much as 5-7 computers. Or as much as a window air-conditioning unit. Or as much as a space heater. Crazy.

Thoughts…?

Fortunately, in Manitoba we have some of the lowest electricity rates in North America, and at about 6 1/2 cents per kwh a 7 WATT item only adds up to about $4/year. Other states and provinces aren’t so lucky, and many pay 2-3 times what we do which means you might be paying closer to $12/year. Not a lot of money (even if it’s for an item you almost never use), but when you have a few of these devices, it tends to add up.

Even at our low rates, the coffee maker would use about $569/year if left on 24/7. Yes, that’s over a buck and a half a day. For those paying 2-3 times what we do, that’s between $1000-1500 a year (or $3-5 per day). That’s a lot. You could buy yourself a nice little Christmas present for that amount of money. At the very least you could buy a coffee maker that automatically shuts off after a little while (which is what I’ll be doing).

Final suggestions:

  1. Invest in a Kill-A-Watt. You can find them for about $30 on eBay. It’ll pay for itself.
  2. Test ALL the electronics & appliances in your house that are plugged in. Write down the power consumptions when turned off. Hopefully most will be near 0.
  3. Do a little math. How much does each device cost you over the course of the year just by being plugged in (or in some cases left on)?
  4. Figure out alternatives for low to mid-range consumption devices. Do you use an item so rarely that unplugging the device is feasible? How about a power bar that can be switched off? If you have a lot of consuming devices in a single area (home theater setup for example), would a single power bar pay for itself? What about a more expensive power bar that automatically kills the power to everything else when you switch off the TV?
  5. Key in on any high-power devices (like the coffee maker). Is it worth replacing (crunch the numbers!), or can you trust yourself to be vigilant about turning it off?
  6. Computers – do you have them set up to sleep after a certain amount of time? Is it working? Should you consider reducing the time before it sleeps?
  7. Keep power consumption in mind when making future purchases. Look for power-saving features, and technical specs. Remember, paying a little more up-front may save you more in the long-run if you’re getting significantly better power savings. Again, crunch the numbers.

Fortunately, technology has helped significantly. Many items nowadays use less power than their previous generation. Nevertheless, it doesn’t hurt to take an active role in seeking out devices that sip power rather than swallow it.