How to Use the Mac's Energy Saver Preferences Pane

Adjust some settings to make your battery last longer

The Energy Saver preferences pane controls how your Mac responds to inactivity. You can use the Energy Saver preferences pane to put your Mac to sleep, turn off your display, and spin down your hard drives, all to save energy. You can also use the Energy Saver preferences pane to manage your UPS (Uninterruptible Power Supply).

Instructions in this article apply to Mac OS X 10.8 and later.

What 'Sleep' Means in Macs

Before making any adjustments to the Energy Saver preferences pane, it’s a good idea to understand just what putting your Mac to sleep means.

Chi Ball of Energy
Phil Ashley / Getty Images

Sleep: All Macs

Some features of the sleep mode are the same on all Mac models, both desktop and laptop.

  • Your Mac’s processor goes into low-power mode, significantly reducing energy consumption.
  • The Mac’s video output is turned off. Any connected display should either enter its own idle state (manufacturer dependent) or at the very least, blank the screen.
  • Internal hard drives will spin down.

Not all third-party drives support spin down or sleep state.

Sleep: Mac Portables

Because they may have different inputs and use cases than their deskbound counterparts, and because they can run on both adapter and battery power, MacBook models handle sleep in some different ways.

You can use Energy Saver Preferences to turn some of these items on and off.

  • The expansion card slot powers off. Any device you've plugged into the expansion card slot will be disabled.
  • The built-in modem turns off.
  • The built-in Ethernet port turns off.
  • Built-in AirPort cards turn off.
  • The optical media drive turns off.
  • Audio in and out is disabled.
  • Keyboard illumination deactivates.
  • USB ports are powered down, although they will respond to specific keystrokes on an external keyboard.

The process of configuring the Energy Saver preferences pane is the same on all Macs.

How to Change the Mac's Energy Saver Preferences

You access Energy Saver through your Mac's System preferences. Here's how to get there and what you can do with the settings.

  1. Open System Preferences under your Mac's Apple menu.

    System Preferences under a Mac's Apple Menu
  2. Click Energy Saver.

    Energy Saver in macOS
  3. The Energy Saver preferences pane contains settings that can be applied to the AC power adapter, battery, and UPS, if present. Each item can have its own unique settings, which lets you tailor your Mac’s energy use and performance based on which power source your computer is using.

    Click the source whose settings you want to adjust.

    Depending on which version of the Mac operating system your MacBook is running, the options may be in a drop-down menu or buttons along the top of the screen. Desktop Macs only have one set of settings.

    Energy Saver preferences in macOS
  4. The first Energy Setting option is called Turn display off after. Adjust the slider to the desired time. You can choose from one minute to three hours, as well as Never.

    The longer your computer stays awake before sleeping, the more energy it will use. This balance is especially important for a MacBook running from battery power.

    You should only use the ‘Never’ option if you dedicate your Mac to a specific function that requires it to always be active, such as server use or a shared resource in a distributed computing environment.

    Turn display off settings.
  5. The next option, Put hard disks to sleep when possible, allows you to sleep or spin down your hard drives during low-demand periods. Doing so will save power without affecting performance because your hard drive will still wake up when the system needs it.

    Put hard disks to sleep.
  6. MacBooks' battery settings in Energy Saver include one called Slightly dim the display on battery power. This option saves power by using less to light up the monitor.

    Slightly dim the display.
  7. Power Nap is a setting that lets your Mac periodically "wake up" to perform tasks like check for mail and perform app updates.

    Enable Power Nap.
  8. The Start automatically after a power failure option is present on desktop Macs. This option is handy for those who use their Mac as a server.

    This setting may not be totally beneficial for general use. Power outages may come in groups, and you'll want to wait until the power seems to be steady before turning your Mac back on.

    Start up automatically after a power failure
  9. Energy Saver also has settings around networking. The Wake for Wi-Fi network access (on a MacBook running from a power adapter) and Wake for network access (on a desktop) tell your computer to leave its sleep state if it detects another computer trying to connect to it.

    Wake for Wi-Fi network access
  10. Another setting unique to desktop Macs and MacBooks running on a power adapter is Prevent computer from sleeping automatically when the display is off.

    Turning this option on will keep your hard drive awake even when the display goes to sleep. When the setting is active, your computer will wake up faster, but it will use more energy.

    Prevent computer from sleeping automatically.
  11. Click the Schedule button to set times for your Mac to start up or wake from sleep, as well as a time for your Mac to go to sleep.

    Selecting Schedule.
  12. On the next screen, click the checkboxes next to the items you want to set. The shutdown and sleep options are available in the pulldown menu next to the second box.

    For the second option, you can choose to put your computer to sleep, restart it, or shut it down at the appointed time.

    Scheduled activities only occur when your Mac is connected to a power adapter (i.e., they won't happen on MacBooks running from a battery).

    Schedule settings for Mac
  13. The second pulldown menu provides options for which days the selected action will occur. You can choose Weekdays (Monday through Friday), Weekends (Saturday and Sunday), Every Day, or a specific day of the week.

    Selecting days to schedule.
  14. Finally, set a time for the wake or sleep action to occur. Click the hour, minute, and AM/PM sections to select each one. Use the arrows or use the arrow keys on your keyboard to adjust them.

    Selecting a time.
  15. Click OK to save your schedule settings.

    Select OK.
  16. One setting that isn't available on all Macs is Automatic graphics switching. If your computer has multiple graphics chips, this option tells the Mac to use the lower-power hardware for less intensive tasks like text editing. If you turn graphics switching off, your Mac will emphasize performance, which will negatively affect battery life.

    Automatic Graphics Switching
  17. Other options may be present, depending on the Mac model or the peripherals your computer is running. Additional options are usually pretty self-explanatory.