Guide to Green Living

Monday, May 22, 2006

Tips to Reducing Your Computer's Energy Usage

Shut down your computer – It is recommended that you shut down your computer when you will not be using it. There are those who believe that leaving their computer on for long periods of time will save energy because of the extra electricity needed to turn their computer off and on again. Though it does take extra electricity to turn your computer on, this is not more than is used by leaving your computer on for more than 10 minutes (approximately). It used to be commonly held that turning your computer off and on again placed it under additional strain and it would die out quicker. However, today’s computers are built to handle thousands of shut-off cycles. So, there is no harm in turning your computer off when you’re not going to be around for a while.

Use built-in power saving features Your computer comes with many power saving features. For example, Windows systems come with features that allow your computer to shut off automatically when it is not in use for a set amount of time. It also has features that turn off your monitor, hard disks, and put your computer into hibernation or standby. When you don’t know how long you will be away from your computer, these features will automatically take action for you according to your settings, saving you energy. You can access these features by going to your desktop, right-clicking and selecting Properties, going to Screen Saver and selecting Power. You can also get there by going to My Computer, then Control Panel, then Performance and Maintenance, then Power Options. Here you choose how long your computer will remain idle for before performing any energy-saving actions. Recommended times are 10 for monitor power, 20 for system standby, and 45 for hibernation/turning off hard disks.

In Mac OS X, go to your Apple Menu, then System Preferences, then click the Energy Saver panel. There are sliders that allow you to choose how long to wait before the system puts your monitor or system to sleep, during idle time. Recommended times are 45 for putting the computer to sleep and 10 for putting the monitor to sleep.

Buying an Energy Star labelled computer is a good start, but is not enough on its own. Having the logo doesn’t automatically mean your computer will be energy efficient, it means your computer has the potential to be. You must use the built-in power saving features to take full advantage of Energy Star features.

Turn off your monitor Your computer’s monitor uses a large portion of the energy consumed by your computer. A good way to save some energy is to turn off your monitor when you are not using it.

Avoid using screen savers When trying to reduce the amount of energy used by your monitor, screen savers are not an effective way to go. They do nothing to decrease the amount of energy used by your monitor; they actually use your monitor at full capacity. Remember, they’re screen savers, not energy savers. The best option is to turn off your monitor.

Turn down your brightness As mentioned above, your monitor uses a lot of energy. To reduce this slightly, you can turn down your monitor's brightness level. The brighter your screen is, the more energy your monitor uses.

Keep your computer off when unneeded Try to break your habit of automatically turning on your computer in the morning, if you do not need it immediately. Also, try bundling your computer tasks to a couple times a day, so you can turn the computer off between uses.

Don't leave chargers plugged in Laptop chargers, and chargers in general, continue to draw power even when they are not actively charging anything. Therefore, it's best to unplug them when they're not in use. For multiple chargers, you could plug them all into a power bar for convenience, as you could simply turn on the power bar when needed. However, if you were to use just one charger, the rest would also be drawing power.

University of Colorado - Boulder's green computing guide (pdf).
Computer energy consumption data from Red River College.
Step-by-step instructions for power management features on Windows 2000 & XP and Mac OS 9 & OS X.
Energy Star guide for computers.

Have any tips of your own? Add them in the comments!


  • Hello there, proprietors of Earth-friendly knowledge! Well, I must say, I actually feel a little more informed. About the compact flourecents, I tried one of them @ home, and it actually didn't last that long... perhaps the wattage was off or something like that? I read the table, and, since there being different wattages incandecent to flourecent, maybe that's why it didn't last as long? Or, maybe because of the repetitive on/off usage too... I mean, it was a bulb on the lights at the top of my stairs, which are on and off on a regular basis.

    But yeah, the 'computer' energy saving thing... I thought the whole 'leaving my computer on' was a good idea, but, apparently now. Good call there. I even lowered the brightness and contrast on my monitor! But I have a question: What does 'degaussing' do? I mean, I could EASILY look it up on the internet, but I figure I'd see how you'll answer my question.

    Okay, well, great work. Look forward to learning a little more on being 'greener' (other than buying a whole bunch of green furniture... or becoming the Incredible Hulk).

    By Anonymous Will Macaalay, at 6/08/2006 11:16 a.m.  

  • Thanks for your comment, Will.
    A wattage is just a power rating, you should really judge your lighting needs based on lumens. As mentioned in the article, CFLs are sensitive to on/off cycles. Maybe you should try them elsewhere?

    Degaussing is basically resetting the magnetic field of your CRT monitor or television. Most automatically do it when you turn them on, so you don't really need to do it manually.

    By Blogger djametcalf, at 6/08/2006 3:21 p.m.  

  • How do you integrate scheduled backup and virus scan strategies with power management? Does using System Standby prevent scheduled tasks from running?

    By Anonymous Anonymous, at 11/18/2007 5:15 p.m.  

  • Go to Control Panel > Scheduled Tasks, and right-click on the task you want to run. Go to Properties, then Settings, and under Power Management, check 'Wake the computer to run this task'. This will wake the computer up from standby to run the task at the specified time.

    By Anonymous Anonymous, at 11/19/2007 1:20 a.m.  

  • HI, I have used the "power saver" option and sometimes the PC will stay sleeping and will NOT wake up. I have had to turn it off and on again.
    I do turn off the monitor whenever I am not working it,but I do leave the PC on overnight. I have found that it does work better that way.
    CE Carrasco

    By Anonymous Anonymous, at 10/08/2008 5:58 p.m.  

  • Reducing your computer's power consumption can be a surprisingly easy way to save money, do a little something for the planet, and extend your equipment's life. For energy savings and convenience, consider turning off the monitor if you aren't going to use your PC for more than 20 minutes and both the CPU and monitor if you're not going to use your PC for more than two hours. If you are one of those lucky organizations that has an IT department that regularly backs up its computers, check in with them about policies around shutting down your computer at night. At the very least, be sure to turn off your monitor, speakers, and other peripherals to reduce your energy usage.

    By Blogger aadi, at 10/15/2010 1:18 a.m.  

Post a Comment

<< Home