Guideline for Energy Saving on Computer Equipment

Energy saving is an important issue to both the environment and the economy. As most of us are using computers and their associated peripherals, such as monitors and printers, we can all contribute in saving energy by turning on their energy saving features. This will save a substantial amount of energy, particularly when the equipment is in idle.

In this document, we will mainly focus on energy saving for desktop workstations (the main system unit), printers and monitors.

In Hong Kong, an energy saving scheme called “Hong Kong Energy Efficiency Labelling Scheme for Office Equipment”, has been launched by the Electrical and Mechanical Services Department of the Government, Computers, laser printers and LCD monitors are classified under this category.

When purchasing new equipment, it is advised to buy registered computer peripherals that have met the minimum energy efficiency and performance requirements of the scheme carry “Recognition Type” energy label.

For detail, please refer to:

For the ENERGY STAR labeled computers with APM (Advanced Power Management) and APCI (Advanced Configuration & Power Interface) enabled, power usage can be reduced greatly when not in use and less heat will be generated, thereby reducing both cooling and energy costs. Therefore, you should ensure that you have enabled the power management feature on your computer in order to achieve energy saving for it.

For more information about Energy Star, please refer to:

Although printers use very little electricity when idle, yet you should enable the power saving feature on your printer if the feature is available. Usually, you should set your printer to enter the power-saving mode after it has been idle for 30 minutes to achieve a good balance between energy saving and convenience.

Furthermore, please remember to power off your printers after office hours. Besides, you can also use timing power switches to schedule.

1. Select dark backgrounds for your screen display.

It is found that white and bright colors (especially in backgrounds) can use up to 20% more power than black or dark colors. Using suitable background colour can save significant amount of energy.

You can do the following steps to change the background:

i. Select Start->Settings->Control Panel->Display->Appearance tab.
ii. Select “Desktop” in the “Item” field.
iii. In the “color” field, select one of the colours that has a low power usage rating such as 
Navy or Black
iv. Click OK.

2. Use a dark screen saver that launches after 15 minutes of inactivity (the display will be restored instantly at the touch of a mouse or key).

The screen saver can be configured by:

i. Select Start->Settings->Control Panel->Display->Screen Saver tab.
ii. In the “Screen Saver” box, select a screen saver that uses mostly dark colours and set the “Wait time” to 15 minutes (or less)
iii. In order to protect your data, it is highly recommended that you set a password to protect your PC when it resumes from the screen saver.

3. Activate the Energy Star feature or sleep mode of your system, with a low-power state set for 15 minutes and a suspend state set for 20 minutes. (If your system only has a suspend state, set it for 20 minutes.)

4. To further reduce the power consumption, you should power off the monitor during extended absences.

Environmental protection is not a difficult task. By following the above guidelines, you can contribute your part in conserving energy and protecting the environment on planet Earth.