I think this is a series of posts on resource use. I have another post on water coming soon. But onward to electricity!
A while ago, we were discussing phantom load, which is the electrical power you use from having something plugged in, but not turned on. I suggested based on my experience with burning out a generator in the wilderness that having a few simple items plugged in (but not on) that all items used power when plugged in.
Anne P. and Scott wondered if phantom load only existed with items with the “wall wart,” like cell phone chargers or fancy lamps, not simple items. So, eventually, I borrowed a Kill-a-Watt from my dad to measure energy consumption of simple items.
Here’s the Kill-a-Watt measurement before I plugged in anything. It shows just around 120 Volts (120.1Volts) right at the outlet, which is appropriate.
Now I plugged in my cell phone charger, which has a “wall wart.” The Kill-a-Watt reads 123.4 Volts, which is what we expected. There’s nothing at the end of the cell phone charger. No phone. Nothing. The Kill-a-Watt shows that the cell phone charger is just using electricity because it’s plugged in.
And then I plugged in a series of other simple objects (all set to off), including a lamp. This cheap lamp apparently does use a little bit of electricity when plugged in, but off (120.9 Volts). Not as much as a cell phone charger, but still some. And this explains how I was able to burn out a generator in a cabin in the wilderness having only simple appliances plugged in and not on (a CD player and coffee pot without any visual displays).
Now this wasn’t particularly scientific. We have an old house with some old wiring. And the Kill-a-Watt seemed to record different amounts when I ran this little experiment again. So with my dad’s permission, I can lend you the Kill-a-Watt through the mail to expand our sample size of items with and without wall-warts. It’s made in China, of course, and is the sort of toy you can use for a couple of weeks before you’ve measured everything in the house three times; it’s ideal for lending. Just leave a comment here if you want this great device.
And why does anyone care about phantom load? Many people are trying to reduce their use of electricity because most electricity power plants in the United States burn coal, which releases greenhouse gases, which in turn warm the planet. So by using less electricity, you are trimming your own electricity bill as well as contributing a bit less to global warming.
How can you apply your knowledge of phantom load to the workplace? I’ll tell you what I do, and you can adapt from there. I simply unplug appliances that I rarely use (like the dreadful fax machine and printer). If you share an office with many people, you’ll need to check before doing much unplugging. Being mindful of your energy use seems part of general mindfulness at work.
October 28th, 2007 at 12:56 pm
What was the amperage on these devices you plugged in?
October 28th, 2007 at 1:38 pm
Well, I was working with Volts, but I’m now thinking I should have been measuring in Watts… (Amps x Volts = Watts).
As far as Amps go, without the Kill-a-Watt plugged in, I show 0.01 Amps used, with the cell phone charger or lamp plugged in, I show 0.03 Amps used both times. I don’t have any sort of amp requirement on the lamp (possibly on the original packaging) and the cell phone charger says it requires 0.35 amps.
I have to admit I don’t understand the particulars, and am wondering if Anne P. would like to ask her physicist-father to explain….but it does seem that in volts and amps there is a measurable amount of electricity used by small items that are plugged in, but turned off.
Would you like to play with this toy? Really, I’d like to get more opinions on what it shows in other homes….
October 29th, 2007 at 6:58 pm
I could dust off my physics knowledge, or ask Dad. Sorry to have missed this comment for a few days. I will try to think more tomorrow when I have more brain cells awake, assuming that is in fact the case.
In the meantime, I’d love to sign up to borrow the gizmo. I’m anxious to find out about this powered TV antenna we’ve got…
October 29th, 2007 at 8:56 pm
I wouldn’t mind playing with the Kill-A-Watt meter. I used to recommend the use of watt meters to some of my customers back when I used to work at the-company-that-shall-not-be-named. (I advised individuals and businesses on how to conserve electricity.) But I never used a Kill-A-Watt device myself. (My electric bill was exactly what I expected it to be given my activity, so I never doubted the usage.)
A lot of devices are going to always be drawing some small amount. TVs have long been a culprit of . At the rate of about 7 cents a kW, a person is looking at somewhere around 15 cents a month per lamp or phone charger like the ones you describe if they’re plugged in 24/7.
October 29th, 2007 at 9:06 pm
Oops; one of my sentences was eaten. Should read above: “TVs have long been the main “silent-load” culprits, but that has changed over the years.”
October 30th, 2007 at 12:03 pm
OK I did a little bit of reading and here’s what I can figure/remember. Tell me if I need to pull dad in on this, but remember, he was once a college professor, so his answers may be long and convoluted
Watts = Amps * Volts, as Ms. T said.
Volts should be basically constant, as voltage is a measure of “potential”, the energy that’s available to come through the wire to you - but it’s not actually moving yet. Here in the US the voltage is about 120, give or take.
Watts is what you pay for (by the thousands per hour, KW/H). Watts aren’t a separate measurement, but sort of a created one - to measure watts, you have to know your volts and amps and then multiply them.
So amps is how you measure how much juice a particular gizmo might use, and either watts or amps would be a better button to push on the front of the Kill-A-Watt to see what’s going on than the volts. Sorry Ms. T. Take your time mailing, if you want to retest
October 30th, 2007 at 12:10 pm
Thanks for doing that research.
I’ll definitely remeasure in amps.
So with nothing plugged in, the Kill-a-Watt reads 0.03 amps. With a lamp or a cell phone charge plugged in (but not turned on), it also reads 0.03 amps, which is, of course, the opposite of my hypothesis. When the lamp is turned on, it shoots to 0.33 amps. I’ll go flog myself now.
So do you think I was measuring random voltage fluctuations?
November 2nd, 2007 at 12:25 pm
I wonder if your Kill-A-Watt might need a little power to operate. I’m glad to hear the lamp isn’t using anything. I thought that was odd, but always open to new evidence.
Please don’t flog yourself! I’ve talked to contractors, electricians, and electrical engineers who get turned around by this stuff.
March 17th, 2008 at 9:53 pm
My mom and I were having this conversation on usage. She has sworn by the fact that unplugging everything not in use is the way to go. She has seen a drop in her electric bill.
I always claimed it to be the weather change or such as that. That is why I researched the matter. I have not completed my research however, you have given me a lot to think about.
May 24th, 2008 at 8:33 pm
If you are still lending your killawatt, i’d love it. putting in a solar electric system and would like to see whats draining that i dont know
would be glad to give you all the info i collect
October 19th, 2009 at 7:01 pm
Thanks really for doing this research.I have made mention of what I have learned on this post to my mom and we actually decided to find one so as to monitor our use of electricity.