Frugal Gadget: Save Money With a Kill-a-Watt Energy Meter

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How much is your TV costing you even when it’s off? How much money would you save if you powered down your computer every night? You can answer these questions with the Kill-a-Watt Electric Usage Monitor The term frugal gadget is no longer an oxymoron 😉

In short, you stick it in between the power outlet and any electrical device, and it’ll tell you how much energy it sucks. Many objects keep using electricity even if it’s not turned on. Get how much you pay per kilowatt-hour from your electric bill, and you can easily find out how much you’re paying to run everything in your house. I really want one of these. At about $25-$30 shipped, I’m trying to justify buying one by getting it to pay for itself in energy savings.

I keep a lot of stuff on all the time mainly for convenience, like my printer, fax, my computer, and sometimes my laptop. Probably not a good idea. It would be cool if you could justify buying an LCD monitor to replace a CRT based on electrical savings costs.

From reading some online reviews, here are some anecdotes (and thus unverified by me):

– An air purifier unit cost about $12 a month, or ~$150 a year to run.

– At 2 hours a day, a TV only cost $2 a year to run.

– A computer running a distributed computing project (like SETI@Home) 24 hours a day cost $27 a month ($324/year).

– Running the same computer with just normal applications 4 hours a cost $5 a month ($60/year).

– Overall, computers can draw from 100 Watts at “idle” up to whatever its power supply is rated at.

– Many objects drain power even if they are doing nothing, called phantom or vampire power. It’s small, but significant enough to add up over time. Power strips can be used to counteract this.

– A lot of times the stated wattage on a device is off by up to 50% of what it really draws according to the manufacturer label.

As I type this, I notice that I should probably unplug my VCR right now, seeing as I have only used it once in the past year. I wonder how much energy my TiVo uses… Anyone have one of these meters?

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  1. Great device. I’m going to unplug my DVD player/VCR combo now that I have DVR. And I’m going to look around for other things to unplug.

  2. I just saw onw of these at Harbor Freight. I think it was about $25. So if you don’t want to pay for shippin gyou may want to try there.

  3. I have one of these things and it’s fun to play with for a little while. It’s especially valuable if you have older appliances where you don’t really know how much power it’s drawing out.

    Phantom power is something we are aware of and we unplug things that we don’t use often and don’t need “instant on” access. The cost savings is minimal but if everyone did it then our energy savings would be tremendous (which would reduce our reliance on those OPEC buzzards who want to keep screwing us with $60 oil).

  4. Great….
    I always wonder how much is it costing me as my DVD/VCR/TV/HOme Theater Sys are all connected to outlet even if their Power is off.. Every time I see the LED I wonder…
    Same with my 2 COmputers that are on 24-7… I do remember to power off the monitor though 🙂

  5. kinda doubtful a computer will hit its power supply rating (these days in the range of ~400 watt) unless its a hardcore rig w/ things such as dual video cards, numerous disk drives and optical drives running.

    not sure about the $37 per month number, but running stuff like folding@home, SETI@home can get mighty expensive…

    this is a pretty neat gadget though. I wonder if there’s an el cheapo version at a lower price?

    computers even at idle can add to the bills overtime, so start making a habit on turning them off 😛 or set them to hibernate/sleep. it’ll save oodles!

    for system builders, consider quality power supply that meets the 80 PLUS program requirement.

  6. I’m not sure if you got this article or idea from kiplinger’s personal fiance issue from last week, but there was a similar article. To make a short post there’s surge protectors that will shut everything off when it’s not being in used, thus saving you money and they list the place you can get these energy saving surge protectors in their magazines.

  7. I am not certain if this is common, but I rather certain that my local library owns one of there that you can check out for a few weeks. Now that is frugal and also makes sense as this isn’t something that one needs on a daily basis.

  8. You’re so right. And I think TiVos are one of the worst offenders. I found a variety of info on this kind of stuff when I was researching a similar post recently, maybe it’ll be helpful to you or others: link

  9. Joseph Cavalieri says

    Yep, I got one of the Kill-A-Watt Monitors. Did you want me to measure some watts for you?

  10. I have one of these. It’s fun to play with for a while, and then you can pass it on to a friend or relative.

    One important thing to keep in mind is that incandescent light bulbs are still going to be some of the highest energy users. A living room with 3-4 lights could easily be 200-400 watts, which dwarfs most electronics.

  11. I think all these newer desktop computers suck some serious juice, as I remember people needing to get bigger power supplies for Pentium 4s or AMDs etc. I wonder how much I’d save if I just used the standby mode on auto like my laptop.

    The idea of having one on loan is great.

    Joseph – Sure, if you have a TiVo, how many watts does it draw on a usual day? Probably as much as a computer, I’m guessing.

  12. Great Timing! I bought one of these last week and used it to find out some interesting stuff.

    Here were some of the interesting results:
    Comcast Box takes up 27w off and 28w on.
    DVD/VCR Combo takes up 10w off
    Old 3 DVD Changer 1 w off
    UPS 1 w on
    Tivo 30w (DVR so you don’t turn it off)
    32″ Sony HDTV 1w off 150w on
    HEPA Filter 46w low, 82w high
    Halogen Torch Lamp 300w full blast, closer to 100w if dimmed
    Table Lamp with Florecent Bulb 18w on
    Laser Printer 300w running, 5w standby
    Monitor 40w on 1w off 1w standby
    Computer 7w off, 145w on
    Lava Lamp 40w
    Cable Modem 5w
    Router 3w
    SinRocket VoIP 4w on, 5w active call
    USB Hub 2w
    Zip Drive 3w
    Speakers 3w

    Saltwater Aquarium
    220W PC Light Hood 168w
    SEIO Pump 21w
    MaxiJet 1200 15w
    Aqua Clear 500 7w

    Changes I’ve made:
    Put all TV accessories that I turn off (DVD/VCR, 3 DVD, Old VCR) on to a power strip to turn off.
    Turn off computer when not using for an extended period of time
    Put computer accessories on power strip (speakers, USB Hubs, Zip Drive) and turn off when I step away from the computer.

  13. I have one and it is interesting to keep track of power usage. The only problem I had with it is that it sometimes shuts down because of overload when equipment with a big electric motor starts up and draws a lot of current momentarily. My main example of this is my dehumidifier in my basement. It tried to start, drew too much current and the Kill-a-Watt shut down.

    Now for a little technical info on it. It displays voltage, current, power in watts, volt-amps, line frequency, power factor, total kilowatt-hours since plugged in and total time since plugged in.

    As for the TiVo, I have a ReplayTV and it draws 30 watts whether it is on or off, recording, playing or just sitting there. (Turning it off just turns off the video output and response to any remote buttons except “on”.) That comes out to about $2/month.

  14. So for Tivo how much does 30 watts 24 hrs/day come out to per month?

  15. I bought the Kill-a-Watt Energy Meter a couple of weeks ago. I hemmed and hawed about buying one as I knew it would sit idle once I ran my tests. Finally, I just bought one to satisfy my curiosity. You can’t manage what you can’t measure.

    Large user of electricity is the refridgerator. Even though my 25 cu ft side-by-side is only a year old it costs around $7/month to run. Ran the meter for a day to verify. You can run the meter for a year if you like. A kwh costs on average is around .15 cents in S. CA.

    Next largest consumers are the TVs. Does anyone have only one TV these days? Check your TV owner’s manuals, they will tell you how many watts these are drawing on and off. On the back of the device you can often find the wattage that it draws. My Sony 27″ TV draws 165w on, 2w off. My mutli-function printer draws 4w when it is off. Like others, the power strips now get turned on when I need to use devices connected to them and are off otherwise. I have 4 power strips with 8 outlets each for my home office that are almost all full. It is amazing how many electrical devices one has these days – cordless phones, external hard drives, routers, ATAs, cable modems, wireless headsets, cell phone chargers, PC speakers, etc. all require their own plugs.

    Any incandescent bulb you are running for 3-4 hours per day is a candidate for replacement with a fluorescent. Fluorescents use 1/4 the power of the equivalent incandescent. They now make fluorescents that can put out more than 100 watts of comparable brightness. They make fluorescents for almost any bulb these days.

    Like others have said, set top boxes consume as much power when they are on as when they are off. My DISH receivers use 18w or 25w depending on the model. They now get turned off when not in use by being connected to a power strip. 25w x 24/hours/day x 30 days consumes 18 kw hours in a month’s time. Here in S. CA that is $2.70/month at .15 cents per kwh. Over 10 years time that is $325. I think you need to look at the long term waste of money to get motivated to make these changes. Per month, the costs do not seem that great.

    Of course the BIG user is the central air conditioning system. My electric bill was $250 for July when temps in S. CA were close to 100 every day of the month. This was cheap. Heard stories of $500, $750, and $1000 electric bills for the month of July. Pool filters are supposed to be major consumers of electricity.

    Jonathon, I think you can cost justify replacing a 19″ CRT with an LCD. Figuring a savings of 60 w per hour for the LCD over the CRT is about $230 dollars in three years time. 60w x 24hours/day x 30 days x 12 months/year x 3 years x .15 kwh = $230 if you are the type that leaves the display on 24×7. 😉

  16. Thanks for all the data! As soon as I find my leftover Amazon gift certificate I think I’m going to buy one of these.

  17. Although I didn’t see it in any of the links, they make appliance timers. Just a more beefed up version of a light timer. This might be useful to turn off those TIVOs if you aren’t recording anything say betwenn 11PM and 700AM. Not sure if this would mess with the hard drive or clock in the DVR. Or I am thinking you can use one attached to a power strip to turn off what is attached to that in the wee hours so you don’t have to remember to do it. One I saw was around $11 at Home Depot and had a 3-prong plug versus the light timers which come with a 2-prong plug.

  18. These are available new on ebay for $24.95 free shipping.

  19. Somebody mentioned above and I’m going to reiterate:
    “Comcast Box takes up 27w off and 28w on”

    The electric bill for a month of using this thing is almost as much as the rental fee. About $3 a month at $0.15/KWH. Have 3 in your house $9 a month in electric to run these god forsaken pieces of garbage. Remember when you could just hook the cable up to your TV? They seem to have virtually no non-volatile memory, so the second it loses power, there goes your program guide. 1 hour later it will finish downloading it again, so the power strip idea is difficult at best. When I go away for the weekend I do shut off the power strip but I really should try to shut it off before bed and before leaving in the morning. For all the time enviro-nazis spend going after automakers and oil companies they really should investigate comcast/motorola for producing such a wasteful appliance.

  20. Anyone found a similar device that monitors gas usage in your car? I know some of the newer cars have the “instantaneous fuel economy” gage but it seems a bit unstable the times I’ve seen it in rental cars. Just thought it would be interesting to know how much it cost me to speed up and get around that slow grandma on the interstate the other day…

  21. Yup I was pretty shocked with the comcast box. I only use it to watch HD channels, but as you say if you unplug it, you lose all data (no-cache) until it downloads everything again. Really weird that it turns on and off given the negligible effect on power usage. I don’t have this on the power strip for that reason. A timer sounds like a good idea though, just have to set it to come on in the morning or an hour before I get home from work and go off at night… (if you use a Tivo and comcast box together for digital cable, you obviosuly can’t do this since you need the signal to be decoded by comcast in order to be recorded on the Tivo)

    Tivo I expected to be like that since it is constantly doing things, and is “always on” I actually have mine on a UPS which has been kinda cool when the power went out for a few minutes then came back on I was able to rewind and see what I missed! 🙂

  22. After reading Jonathan’s plug for this product I paid $29.99 with free USPS Ground at Amazon for one. Prob is it won’t work for me. I stuck it in an outlet and plugged in a microwave using several different settings. Nada! All those eights on the LCD just stuck there & no amount of pressing buttons could persuade them to stand aside and allow data to appear. I’m tempted to return the product to Amazon & request my money back — unless some more technically savvy Samaritan can suggest what I may be doing wrong.

  23. Seems like the drawback of managing consumption through a power-strip is relying on the user to remember to switch it off/on all the time. I’ve not tried it myself, but something like this looks promising:

    Anyone tried this?

  24. My Kill-a-Watt turned out a nonkiller for me so today I shipped it back to Amazon for a refund. This was just one more “Made in China” product that failed to deliver. When, I wonder, will Old Reliable (aka Uncle Sam) get back in the small electronics-manufacturing biz? I just bought power-saving LED flashlights for possible emergency use during the cold winter ahead. The e-tailer was who ship to folks like firefighters who absolutely must have reliability. Still, the words “Made in U.S.A.” made the sale for me.

  25. Scott there is a device that can monitor your MPG. You plug it into the data port under your steering wheel the same one they use to diagnose your warning light. You leave it in there for a month then plug it into your computer and it will show you a lot of different data. Some of them are mareketed so you can spy on your teen when there driving to find out if there speeding.

  26. This gadget looks to be very useful. We did not know of it, but will surely check it out. To be on the safe side and protect all our electronics equipments / gear, we turn them off the power when not in use. Sometimes it causes inconveniences, but the payoffs are way greater than the slight occasional discomfort. Thanks for the great post though.

  27. If you want it, you can buy one for $19 at here. Use coupon code silverbells to get $5 off the original price.

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