Lori Bongiorno

Energy vampires: Fact versus fiction

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It's well-known that most electronic devices in our homes are sucking up energy even while they are turned off. But for all the information out there, many questions remain. I got hundreds of reader questions after writing the post What's wasting energy in your home right now. Below are answers to the five most common inquiries:

Which electronic devices waste the most energy when they are turned off but still plugged in? 

Set-top cable boxes and digital video recorders are some of the biggest energy hogs. Unfortunately, there's little consumers can do since television shows can't be taped if boxes are unplugged. It also typically takes a long time to reboot boxes.   

However, some of the other major consumers of standby power are more easily dealt with: computers, multifunction printers, flat-screen TVs, DVDs, VCRs, CD players, power tools, and hand-held vacuums. The Lawrence Berkeley National Laboratory (LBNL) measured standby power for a long list of products.  

While it's true each individual product draws relatively little standby power, the LBNL says that when added together, standby power can amount to 10% of residential energy use.

Why do electronic devices use energy when they are switched off?   

Electronics consume standby power for one of two reasons, says Chris Kielich of the Department of Energy. They either have an adapter that will continue to draw electricity, or they have devices (such as clocks and touchpads) that draw power. Anything with a remote control will also draw standby power, she says, since the device needs to be able to detect the remote when it's pushed.

Does everything suck energy when it's plugged in and turned off?

No. If your coffeemaker or toaster doesn't have a clock, then it's probably not using standby power, says Kielich. Chances are your hair dryer and lamps (although they may have a power adapter for the dimmer) are not drawing standby power either, she says. Devices with a switch that physically breaks the circuit don't consume standby power.

Will switching things on and off shorten their life?

Probably not, says Kielich. You'd have to turn devices on and off thousands of times to shorten their lives. The real downside, she says, to unplugging electronics is that clocks and remotes will not work, and you do have to reset everything.

Can you ruin batteries by unplugging battery chargers and causing batteries to completely discharge?

It could be a possibility, says Kielich. Her advice: Don't let batteries get completely drained. But you don't need to have things like hand-held power vacuums and drills plugged into the charger when it's 100% charged, or even 50% charged.

Power Strip FAQs

Plugging electronics into a power strip and turning it off when you're not using it is a widely prescribed solution for curbing vampire power. Here are answers to common questions: 

  • Power strips draw energy when they are turned on, but not when they are switched off.
  • Any decent power strip should have surge protection, according to Kielich. Flicking your power strip on and off will not create a power surge capable of damaging electronic devices. In fact, it will protect devices from other surges. 
  • Several readers were worried about the possibility of fires caused by plugging too many things in at once. If you plug in the allowed number of devices, then power strips are safe, says Kielich. Just don't plug your power strip into another power strip, or you run the risk of creating an overload. 

Environmental journalist Lori Bongiorno shares green-living tips and product reviews with Yahoo! Green's users. Send Lori a question or suggestion for potential use in a future column. Her book, Green Greener Greenest: A Practical Guide to Making Eco-smart Choices a Part of Your Life is available on Yahoo! Shopping and Amazon.com.

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comments from our community

Showing 631 - 645 of 645 comments

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  • Posted by eric Mon Oct 12, 2009 12:29am PDT
    you c
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  • Posted by xrox Tue Oct 13, 2009 7:40am PDT
    I have a family of 6 and someone is always home alway on tv, intenet or something. Elec bill has been over $300 a month all summer, hot summer in the DC area. I've tried trimming closing blinds, and running around turning stuff off like a mad man all to say ARRGGG when bill arrived. Finally cool weather AC not on and first bill dropped in half. I agree turn off everything you can but the proof is the the big bang heat and air.
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  • Posted by Djoko Tue Oct 13, 2009 10:25pm PDT
    Electric Technology until to day had used The Sun, the Wind, The Water also Geo thermal those are prepared by the Nature inexpensive simple. The question is, could the next technology of electric could be transfered by microwave or something in wireless?
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  • Posted by Henry R Sat Oct 17, 2009 11:00pm PDT
    The reason that trickle current runs through electronic devices is to limit the surge current from turning a device on from being completely off with no current going through the boards. I'd rather pay 10% extra on trickle current than have to replace my electronic devices early.
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  • Posted by florencelukoma Tue Oct 20, 2009 7:18am PDT
    electric devices should be swtched off and plugged out for protection of all electric items in a home, even the duration of the items becomes long because of high care and responsibility
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  • Posted by go.daystar Fri Oct 23, 2009 11:35pm PDT
    i've read some nice guidelines re "how to maintain high-tech batteries" on the Apple website (somewhere in the iPod or General or Support section) .. perhaps everyone should read that ... gist of what i learned there is not to leave batteries unused a lot .. like if you're mostly plugged-in to mains then try to run your device on the battery every few days; don't deplete the battery all the way, 50% is ok ... the ions inside a battery need to move for the battery to stay healthy .. they move when the battery is in operation in USE or CHARGE state! Rechargeable Batteries generally go kaput if left uncharged for 90 days! So, when buying RB's try to buy ones that are very fresh out of the factory, 'k?
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  • Posted by darrel m Mon Oct 26, 2009 5:28am PDT
    bla bla bla
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  • Posted by RussellK Tue Oct 27, 2009 7:48am PDT
    Response to those who really don't see the picture: Jeffery said he checked the power draw of various devices and found they draw nothing. The problem with this is he did not have testing equipment sensitive enough to see 2 to 5 watts of power. Not much power true, but multiply that by the number of TVs, DVDs, VCRs, electronic clocks, computers, battery chargers, audio amps, etc, etc, there are in the US. In 2006 there were 111 million TVs in the US, about 100 million VCRs, 80 million DVDs, and 60 million computers each one drawing conservatively 3 watts of power when turned "off". Some more some less. Do the math. It's over a thousand megawatts of power being used for these basic devices just so we don't have to get off our lazy obese rumps to flip a switch. This does not include the hundreds of millions of other devices we leave plugged in. The global warming alarmists should appreciate the fact we could shut off more than a few coal fired power plants in the US if we just eliminated "instant on".
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  • Posted by William Tue Oct 27, 2009 7:17pm PDT
    I'm having a disagreement with my girlfriend : I opine that leaving our cellphone chargers plugged in while not actually using them to charge the phones may be an excellent way to not misplace the charger but it sucks energy 24/7 while its only needed for what - an hour or 2 a week? She argues that the energy leakage is minimal. We disagree on nothing else, BTW - this in the ONly issue we don't 100% agree on(wink&nudge). So, whats the verdict?
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  • Posted by bifferos Thu Oct 29, 2009 6:30am PDT
    People are lazy. They like standby because it saves them reaching down to turn stuff off. There are countless labour-saving devices, and we'd use less electricity without them all, why pick on standby? Why not just avoid having the video altogether, you don't really need it do you? Unless you're reading a book, most houses can probably be lit by a couple of watts of power, LED head-torch anyone? Unfortunately, most green activities involve cost-saving, and meaning more money for mobile phones, plastic goods, foreign holidays etc... The only way to make people truly 'green' is to take their money away, sad fact of life.
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  • Posted by Brandy Thu Oct 29, 2009 7:41am PDT
    That is good intel. I knew many devices stored electricity...but didn't realize they actually kapt draining to respond to remotes...etc.... unplug everything, ai!
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  • Posted by RussellK Sun Nov 1, 2009 7:04am PST
    Why not pick on "standby"? In standby your video device is not entertaining you is it? It is just sucking power while you sleep. Ridiculous. You are correct, I really don't need my video device but I do enjoy it.
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  • Posted by JulioS Wed Nov 4, 2009 12:09pm PST
    thank you so much i will start saving some money right now.
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  • Posted by CHRISTOPHER W Fri Nov 13, 2009 6:54am PST
    The small refrigerators,like the students use in thier dorms can use an average of 30 dollars per month.Air purifiers and dehumidifiers are energy suckers depending on thier size.My dehumidifier/30$----Air Purifier/25$.
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  • Posted by altered_intentionz Wed Nov 18, 2009 7:42pm PST
    that really depends on the battery type so do your research, older batteries did have this "flaw" but many new batteries have no such "memory" so you can charge them whenever you want, how conveniant is it to have a cell phone with a dead battery when your REALLY need to use it?
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