Putting the Kill A Watt to work to detect phantom power loads

March 4th, 2010 by Cathy Rust Leave a reply »

Phantom power load is a term that refers to how much power your electronic goods are drawing even though they might be turned off. In order for your TV to turn on instantly, it requires a certain amount of power so that it doesn’t go through the “warming up” phase that TVs used to do. The benefit of course is no waiting. The downside is even while you’re not home, you have electronic items and appliances that are drawing power unnecessarily.

Identifying phantom power loads:

While I’ve written in an abstract way about how effective the Kill A Watt is at measuring the amount of energy your appliances consume, I thought I’d share our experience using it. We measured the energy consumed by the appliances listed below.

Big, honkin’ Basement TV (Toshiba):  Off: 0 Watts              On: 165 Watts
Sony PS3:                              Off: less than 1 Watt   On: 95 Watts
Digital TV box:                     Off:  11 Watts                On: 12 Watts
VCR:                                       Off: 5 Watts                 On: 12 Watts (“play” mode)

Total phantom power load

  • when TV is off: 16Watts (digital TV box plus VCR).
  • Total Kilowatt Hours per year: 116kwh per year (estimate: 16 Watts x 1/1000 Kilowatts x 20 hours per day in standby x 365 days per year).

While the Sony PS3 has to use a little bit of power even when “off” (because of the on/off indicator light), it is less than 1Watt so it isn’t recorded by the Kill A Watt. Let’s say it draws slightly less than 1 Watt. In a year, it would use about 8 kwh of electricity. This is the same amount for our 4 cordless phones, but they’re used less often so they draw about 8.5 kwh x 4= 34 kwh per year in phantom loads.

Computer and accessories:

Hard drive:                  Off: 4 Watts         Standby:  5 Watts        On: 88-130 Watts (depending on amount of activity)
printer:                          Off: 0  Watts        On (idle):  5 Watts       Printing: 16-20 Watts
Router:                          Off: 0 Watts         On: 5 Watts
Monitor:                        Off:  0 Watts       Standby: less than 1 Watt      On: 37 Watts

Total phantom power load

  • when computer is “off”: 4 Watts.
  • When computer is in “Standby”: 5+ Watts.

Phantom power consumption per year is approximately 20 KWHs. (estimate: 4 watts x 1/1000kilowatts x 14 hours/day in off mode x 365 days per year).

What does this mean?

We have fairly good behaviour patterns regarding our electronics. The boys turn the TV and game systems off when they’re not using them. The one glaring fault I see is leaving the VCR plugged in. We use it so rarely and it’s drawing 43.8 kwh per year. I was surprised at how little power our TV and PS3 drew when turned off, but also surprised that the computer, even when completely off was still drawing 4Watts of power. I was at my local Home Hardware the other day, and while they didn’t carry a power bar with a timer, they did have a Smart Strip so I bought that instead.

The Smart Strip: If you’re not familiar with the Smart Strip, it’s a surge protector that goes a step beyond a basic power bar. I’d read about it on Treehugger but now having used it, the jury’s still out as to whether this is a good investment for our specific purposes.

Smart Strip

How it works: You plug your primary device into the “control” plug. The primary device is usually the TV or computer hard drive. Plug the peripherals (screen, printer, modem) into the controlled outlets. Any peripheral, such as a fax machine or cordless phone, that you want to keep on all the time can be plugged into two uncontrolled outlets.  The power bar is activated with a sensor that monitors electricity flow changes from the primary electronic. When power level decreases when the primary device is turned off, a signal is sent to shut off peripheral devices thereby eliminating phantom draw.

I decided to try out the Smart Strip with our TV/PS3/Digital Box option. I’m not sure this is the right way to go because the digital box will have to reset everytime the TV’s turned on but in theory it will save about 80 kwhs per year of electricity. The Smart Strip itself draws a minimal amount of power unless you turn the whole thing off, and then you might as well just use a regular and much less expensive power bar. My concern is the daily resetting of the digital box.

We shall see how successful this Smart Strip is, but for $39.95, it might be more suited to a home theatre system or a bigger home office than our small plug load. Our better bets would be to get rid of few cordless phones and eventually replace  our TV and computer hard drive to Energy Star models, and to use a power bar with timer for the computer and TV set-ups.

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