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Computer Power Management

Introduction

Computer power management is a set of features that help reduce power consumption by placing monitors and computers into a low-power "sleep mode" after a period of activity. Simply touching the mouse or keyboard "wakes" the computer and monitor in seconds.

Types of Power Management

There are 4 basic types of computer power management or "sleep" features on Windows PCs:

  1. "System standby"
    Drops monitor and computer power use down to 1–3 watts each
    Wakes up in seconds 
    Saves $25–75 per PC annually
  2. "System hibernates" 
    Drops monitor and computer power use down to 1–3 watts each
    Wakes up in 20+ seconds
    Saves work in the event of power loss 
    Saves $25–75 per PC annually
  3. "Turn off monitor"
    Drops monitor power use down to 1–3 W 
    Wakes in seconds or less 
    Saves half as much as system standby or hibernate: about $10–40
  4. "Turn off hard disks" 
    Saves very little energy

Advantages

Activating Power management features provide many benefits including:

  1. Cutting the electricity used by PCs roughly in half, saving $25–75 per PC annually.
  2. Enhancing data security by reducing the chance that valuable personal information is displayed on an unattended PC.
  3. Saving time by eliminating the daily wait for computers to boot up.

Recommendations

The recommendation from IT is to follow EPA best practices and activate the following power management settings:

  • Computers will be set to enter system standby after 30 minutes of inactivity. This reduces power consumption from as much as 250 watts to less than 2 watts.
  • LCD monitors will be set to enter sleep mode after 15 minutes of inactivity. This reduces power consumption from 35 watts to less than 2 watts.

The most efficient way to activate these settings is to implement a policy in Active Directory. You can also activate these settings manually. Instructions are available at View instructions. Please note that when these settings are enabled, you will be unable to access your computer from a remote location.

FAQs

Q: Are there any documented best practices?

A: The Environmental Protection Agency (EPA) recommends setting computers to enter system standby or hibernate after 30 to 60 minutes of inactivity. The EPA recommends monitors to enter sleep mode after 5 to 20 minutes of inactivity.

Q: Will my computer still automatically receive software updates and security patches even in "standby" or "hibernate" mode?

A: Computers with power management features activated will still receive software updates such as new antivirus definitions and Windows security patches. Active Directory and Group Policy are designed to facilitate software updates.

Q: Can my computer use power management features even if I’m trying to remotely connect to it from another computer located off campus?

A: Computer users requiring remote access to their desktops should use limited power management features such as “turn off monitor” and “turn off hard disks,” as it may not be possible to remotely "wake" computers from "system standby" or "hibernate" mode.

Q: Does using a screen saver help save energy?

A: Screen savers generally do not save energy. In fact, certain graphics-intensive screen savers can cause the computer to burn twice as much energy, and may actually prevent a computer from entering sleep mode.

Q: Do computers and monitors use more energy with power management features activated due to power surges when cycling on and off?

A: Many people believe that leaving lights, computers, and other appliances on uses less energy than turning them off and also makes them last longer. But according to the Government’s Energy Star Website, the small surge of power created when some devices are turned on is vastly smaller than the energy used by running the device when it is not needed.

Q: I use a Mac, how do I enable power management settings?

A: Macintosh power management cannot be enabled via Active Directory and Group Policy. Please enable these setting manually. View instructions.

Learn More

Learn more about power management for your computer and other appliances by visiting the Government's Energy Energy Star website at. If you have any questions about computer power management, please contact the IT Help Center.