Save $100 By Simply Turning Off Your Computer

Save by turning off your computerRunning your computer is pretty darn cheap when viewed at an hourly rate – approximately $0.02 an hour. This figure was obtained with the following assumptions: The typical desktop computer uses around 200 watts of energy per hour (with a 50% / 50% split of energy consumed between the computer and the display screen). We pay about $0.10 per kilowatt hour for electricity where I live (this varies across the US, so you can put in your actual rate here). From there you simply divide the watts used by 1000 (since electricity is charged at a rate in kilowatts – 1000 watts) multiplied by the rate charged: 200 divided by 1000 = 0.2 x $0.10 = $0.02.

With the cost of using a computer so cheap, many people believe that it isn’t worth the time to bother turning it off. When multiplied over time, however, it can add up. That $0.02 an hour comes to $0.48 a day, $3.36 a week, $13.44 a month and $175.20 a year if you leave your computer on 24 hours a day, 7 days a week.

That means if you turn off the computer for half the day while asleep, you have saved $87.50. Add in a few extra hours it will likely stay off on the weekends, and you have reached $100 a year in savings by simply turning off your computer. If you have a small business with 10 computers, making sure they get turned off at night means an extra $1000 to your bottom line (and if you work for a business that rewards employees that submit money saving ideas that get implemented, you could even earn a bit of money by suggesting this).

You may have some other arguments for not turning off the computer like doing so will put extra stress on the computer’s internal components. While it is true that there is a slight “stress” each time the power is turned on due to the heating and cooling, this stress is quite small. It can also be argued that it is balanced out by giving the moving parts of the computer like the fan a rest. Turning your computer on and off should not shorten its life.

I’ve also heard the argument that computers use much more energy starting up so that it makes more sense to leave them running all the time since this will cost less. I haven’t been able to find any study that supports this (that you save more money leaving a computer on for 12 hours than turning it off and on again) and it appears to be a urban legend.

Those issues having been addressed, let’s be perfectly honest – shutting down your computer can be a real pain. This is especially true if you typically run a number of programs at the same time which all need to be configured with certain documents. It can also be a pain if you leave your computer on at night to run timed tasks such as virus protection updates.

There are also a number of legitimate reasons why you may not be able to shut down your computer at night. If your computer handles network or Internet tasks at all hours (as a de facto server), you can’t turn it off. If you participate in web based computing tasks such as searching for intelligent life in outer space then you may not want to turn off your computer.

If this is the case, there is still a step you can take to reduce the cost of running your computer (and if you can turn off your computer, this further reduce your costs). You can do this by placing your computer into sleep mode (there is a misconception by many that screen savers reduce the amount of energy the computer is using. Unfortunately, this is a myth and a computer running a screen saver is using just as much energy as one that is in use). While your savings won’t reach $100, it can reduce the cost by as much as $50.

Either way, taking one or both these steps will save you some money with little effort as well as help save resources.

More Saving Tips: How To Save Money On PS3 & Wii – Lifetime Financial Lessons

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34 Responses to Save $100 By Simply Turning Off Your Computer

  1. Mike says:

    As far as the computer consuming more power on start-up, that is true.

    Hard drives will draw up to a couple/few amps to spin-up the platters – that is why enterprise drives (and some consumer drives) have “staggered startup” to reduce that large surge multiplied times a dozen drives. HDs drop to a more reasonable level (less than an amp) once up and running.

    That’s just one data point since you said you had never seen any information about higher current-draw on startup. However, I agree that long-term in a home-use setting, it’s advantageous to turn the machine off/suspend it between uses.

    Oh, one more thing – on very old hard drives, they almost always fail after a power cycle because the temps changed and the added stress of spinning-up cannot be handled. At work, we *hate* moving the workstations because it’s so very common that a drive will not come back up after the move/power-cycle. Of course, if you are using a drive that’s so old to have this as a problem, you should be getting critical data off of it and preparing to order a new one ;^)


  2. Mike says:

    Oops – forgot to paste a link.,1084,783,00.html

    Look at the Electrical Requirements section. The startup current on the 12v line is 1.76A vs. .76A operating – an increase of 2.3x during startup (which is brief) and that’s on a very modern, very high-end drive – older ones are potentially less efficient.


  3. pfadvice says:


    thanks – my poor wording. I have added a bit to clarify what I meant.

  4. Super Saver says:

    Another source of power drain are all the electronics that have standby modes. These include TVs, Microwaves, DVDs, Amplifiers, etc which have LED or infrared elements that are always on. While individually small, they do add up.

  5. Ralph says:

    I only turn off the PC if its not going to be used for a couple of days as it wastes a few minutes of my time waiting to start up the OS and launch apps etc. so the saving isn’t worth the inconvenience. But, as you say, 50% of the energy is used by the display, so I just turn off the display when not in use, as the screen comes back on almost immediately.

  6. fractalbrothers says:

    we have a computer room, we just leave them on at night during the winter, it helps heat the house =P

  7. And people think I am crazy to trun it off..actually I find the more it is off the more non computer work I do, it took some adjusting, and many may not like skipping the computer use, but for my house, it seems to help (regardless of the electric bill)

  8. samerwriter says:

    A few more tips; when buying a computer, you can sometimes upgrade to a lower power processor (or a processor that supports more advanced power mangement) for a small fee. If the price is close, that might be a money saving option.

    If you don’t want to shut down your computer, some computers support a standby mode. That keeps a few key parts of the computer powered (memory contents, for example), while putting the processor into a low-power state. This is different than the sleep mode you’re mentioning above, which only affects the monitor.

    Some computers support “Wake on LAN”, so even if your computer is a server, as long as it’s pretty low-traffic you may still be able to let it standby.

  9. PSW says:

    I find it depends on where in the house I have my computer. I use a laptop, so if its in the bedroom I will always turn it off, but if it’s out of sight, then its out of mind and I leave it on.

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  11. Eddie says:

    Ya, but you don’t take in to account that every computer since say 1996 or so is an Energy Star compliant device. When your screen saver puts your monitor into sleep mode it’s power comsumption drops to dman near nuttin’. Hibernation turns the computer off, so we won’t look at that, but an energy saving sleep mode on the computer shuts down the harddrives and reduced motherboard power consumption to like 5%. — And the poor sysops working at night can still access your machine remotely to fix it without having to roam around the darkend office turning all the computers back on!
    — I have clients 100 miles away that I can work on remotly as long as they don’t turn the machine all the way off. They do that and I have to get in the truck and burn 2 freaking hours to walk in, push the power button, and go home.

  12. Henry says:

    It’s obvious that computers consume much more power whilst running than during start-up: this is why your laptop battery lasts a lot longer if you put your computer on stand-by/hibernate when not in use!
    That said, all the electricity ‘used’ is eventually converted to heat, you can simply view your computer as a 200W heater with added benefits!

  13. Matt says:

    Just configure your power savings setting to be: “standby mode” when you press the power button. That’s pretty easy to do, and it wakes back up in seconds when you hit the keyboard.

    You can still shut off the computer completely by using the Windows Shutdown sequence it you so desire.

  14. vincent says:


  15. cytral skunk says:

    Turning your PC on sends an electrical surge through every part of your motherboard. In the Post-Energy Star era, its wiser to leave your systems on (assuming you have a good surge protection system).

  16. jersey jen says:

    Corporate America needs to stop keeping computers on during off-work hours . . .

  17. James says:

    $175.20 a year is nothing, now if it was $175.20 a month maybe i’d consider it.

  18. Eugene says:

    What about the environmental issues… Everybody should switch off their computer whenever possible (even if it is only for the future of your children and grandchildren….)

  19. gumbo says:

    This is absolute crap. Those calculations are incorrect. I leave my compter on 365/24/7 and my bill is only $40 a month at the most….for everything. Are you taking into account the fact that a computer has sleep mode and uses little to no power when the hard drive is not spinning, the fan isn’t on and the monitors are on standby?

  20. Keith says:

    That is very true. I do feel that leaving the computer on running is a total waste of resources, I think this effort should be made worldwide, so every single being on earth can do their part.

    In technological terms, I do hope PC and processor chip makers can also modify the design to allow lower power consumption, yet running at higher speed.

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  24. Rebecca says:

    I always turn off my computer when it is not being used whether it be my home computer or my work computer.

    question: If we leave our computer on 24/7, does that leave it vulnerable to trojans, virus, computer hijacking, etc.? Sometime back I heard leaving on your computer 24/7 could result in someone hijacking your computer.

  25. pfadvice says:

    If we leave our computer on 24/7, does that leave it vulnerable to trojans, virus, computer hijacking, etc.? Sometime back I heard leaving on your computer 24/7 could result in someone hijacking your computer.

    I think the danger is if you say connected to the Internet 24/7 – not if you just have your computer on.

  26. mike says:

    so… buy one less coffee a day, set your monitor to auto power off after 20 minutes, and bam your in business and saved more money.

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  28. Brian says:

    If you lose one minute of productivity a day waiting for the computer to start up you have lost over four hours, A far better solution is to use sleep mode.

    Also, leaving a computer on in winter would add virtually nothing to the energy bills, while in summer you should take much care to turn lights off when not in use, after all you are paying for the lighting electricity three times in summer(once for the light, twice for the air conditioner).

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  30. derrik says:

    What really rocks is Mac osx and its ability to wake up after closing the lid on the powerbooks. Not sure how that impacts usage and battery recharging, but it solves the problem of slow rebooots.

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  32. Kelso says:

    Great information provided. I am proposing turning off computers at the high school where I teach to save energy. Thanks again.

  33. Allison says:

    I wonder if upgrading the computers to the new ones saves enery and money?

  34. Jackie says:

    Could you provide me with a poster that can be hung up at schools or for teenagers at home with VERY CLEAR, short worded guidelines. For example:
    1) Turn computers off when not in use after half an hour
    2) Computers and lap tops hibernating or on standby (and whatever other settings) still take power
    3) Printers should be turned off at all times
    4)Monitors should be turned off
    5) ETc. etc.
    Too much information people do not read. Whereas, bold dos and don’ts are easier to read . If you could provide me with the above, much appreciated.

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