AskPablo: Phantom Power

Happy New Year! I hope you are all ready to make some New Year’s Resolutions for sustainability. Will it be resolving to ride your bike to the store more often? Will it be to eat locally-grown food more often? Will it be to offset your vehicle’s carbon emissions? Well, how about adding one more to your list: getting rid of phantom power…

What’s that you say? Phantom power is the undesired use of electricity by appliances and battery chargers all around your house. Most DVD players and Microwaves are essentially inefficient clocks (when you can figure out how to set the time) that occasionally play movies and heat leftovers. Most chargers, like for your mobile phone or digital camera, remain plugged in to the wall outlet even though you are no longer charging your device. All of these devices use more electricity than you would think just to be on stand-by for you. Let’s have a look at just how much energy is wasted and what you can do about it.
I will need to use a new toy I got for Christmas, called a Kill-A-Watt. This great device, made by P3 and available from Europort (, 978-282-8895), measures various aspects of a device’s power use. It can track the kWh used, the current Watt or Amp usage, the outlet voltage, the outlet frequency, etc. When I plug the device into the wall outlet I can see that we have between 119.5 and 120.3 V at 59.9 Hz. These values may change a bit depending on the “quality” of your electrical supply and is based on factors such as the distance from the substation and the usage levels in your neighborhood. In the US the ideal is 110 or 120 V at 60 Hz, while Europe uses 230 V (+/- 10%) at 50 Hz. Hertz (Hz) means “cycles per second” and refers to the rate at which the alternating current (AC, as opposed to direct current, DC) alternates between positive and negative voltage. To read more about AC and DC, check out Wikipedia.
I used the Kill-A-Watt to measure the electricity use of several household items. First I looked at various power supplies, mostly from cell phones and other small electronic devices. I found that, while not in use, they draw 0.01-0.02 Amps, which is equal to 1.2-2.4 W (0.01 A x 120 V = 1.2 W). Keep in mind that an average compact fluorescent light bulb uses around 11 W. Using the same method I determined that my laptop computer’s power supply uses roughly 7 W while plugged in. I also found a TV/VCR unit to use 5 W in standby mode and a microwave that, remarkably, only used 1.2 W (to tell me the time).
Let’s say that I live in the average household. Let’s assume that the average household has two mobile phone chargers, around 5 more chargers and power supplies for various other electronic devices (your Dust-Buster Vac, your I-Pod charger, etc.), two laptop power supplies, one microwave, and two TV/VCR combos (or one TV, one VCR, and one Stereo). This adds up to 37.8 W (1.8 x 7 + 7 x 2 + 1.2 + 10). That’s enough to power three CF bulbs around the clock! In one day this amounts to 0.9072 kWh of energy, or 331 kWh per year ($53.80 at current CA rates).
If we assume that the 105,480,101 households in the US (2000 census) are just like this one, we are wasting 34,913,913,431 kWh per year, or $3.5 Billion (assuming $0.10 average US cost per kWh)!! Surely you can think of a better use for all that money, like schools or Tickle-me-Elmo’s… What’s even worse is the cost to future generations because, at an average US emission rate of 0.35g/kWh, this amounts to 12,220 additional metric tons of CO2 per year. Would someone please ask small-electronics manufacturers to cough up the $100,000 to offset these unnecessary emissions?
So that’s the bad news, here’s the good news: You can do something about it! You don’t need to get yourself a Kill-A-Watt, but it sure is fun! Here are a few ideas to help you cut your phantom energy use. Plug all of your computer peripherals into one power strip. When you are not using the computer simply switch off the power strip. This will instantly eliminate a great deal of your phantom energy use. Consider adding your mobile phone charger and other chargers to this strip as well. Most devices don’t need to charge for more than a few hours a day. You can also just try to remember to unplug the chargers when you are not using them. Microwave ovens and TVs (indeed whole entertainment centers) can be put on a switchable power strip. You don’t need that clock 24/7 anyway!
Don’t forget to AskPablo! Send me any burning sustainability questions that you have and I’ll do my best to give you an answer.
Pablo Päster, MBA
Sustainability Engineer

3 responses

  1. hi thier my name is kier mizuik i’m starting to open a company for energy efficent products
    the web page is here in atlantic canada . we currently rent hot water
    tank from a government owned utility n.b.power
    a 60 gallon tank heat hot water to 140 degrees
    at 12.8 amps / but i’m found a pre heater called
    nyletherm-1 from nyle special products that heats
    hot water to 140 degrees while it dehumidifies
    and air conditions for only 4 amps of power and costs 1499.99 retail canadian dollors .could you help me with the math ? i would like to be able
    to have a dayly savings / unit in watts and kws
    as well as money values .electricity here is .08/kw .the big numbers are we have 660000 tanks in this province alone .all so what kind of
    co2 emitions could be saved if 1000 units were changed at a time or for that matter the hole
    system …. would you be interested in a link from my web page to yours .yours truly kier mizuik

  2. any idea what a desktop computer uses when not turned on, or when it’s in ‘sleep’ mode? i’d love to get my office to turn off more than just the monitor at the end of the day…seems it would save us money, as well as electricity….

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