Purchasing requirements for computers
Because there is such a large variation in power consumption for computers, you can halve the consumption by choosing energy efficiently when replacing equipment.
Savings of up to EUR 135 can be made over the life of the equipment of each unit. Save most by choosing notebook computers instead of desktop models. This also frees up space on the desk.
Types of computers:
Requirements conform to Energy Star specifications effective from 20 July 2007.
The requirements apply to standard types of personal computers connected to mains electricity, including types with external power supplies, and types that can operate on charged batteries. Power consumption and times are the maximum permitted for energy efficient equipment.
Notes and additional definitions – Personal computers
(1) On is the idle mode with the computer running the operating system, etc., but excluding user activity. Monitor is switched off on integrated and notebook computers.
(2) Sleep mode is a power saving mode which the computer (but not server) automatically enters after a period of inactivity, and ‘wake’ facility which quickly allows programmes and documents stored in memory (RAM) to be recalled.
(3) Computer is in Standby (off mode) when the user switches off in the normal way via the operating system.
(4) Includes integrated computers with monitor, smaller desktop-derived servers and game consoles.
(5) Category A: Standard types of desktop office and home computers which are not in category B or C.
(6) Category B: Powerful computers with high-performance multi-core processor(s) and minimum of 1 gigabyte of system memory.
(7) Category C: Powerful computers with high-performance multi-core processor(s), and graphic card (graphics processor with minimum of 128 MB of dedicated memory), and with 2 out of 3 of the following attributes:
(9) Category B: Powerful notebook computers with high-performance graphics card (graphics processor with minimum of 128 MB of dedicated memory).
(10) The highest level requires additional functionality for network card (WOL: Wake on LAN, which enables switch on from a network).
(11) Computer must switch off separate or built-in monitor within 15 minutes of user inactivity.
(12) Internal or external power supplies must be energy efficient, e.g. minimum 80% efficiency for internal power supplies (at 20%, 50% and 100% load under maximum power output), and conform to the Trust’s requirements for external power supplies.
ENERGY STAR Program Requirements for Computers: Version 4.0 provides a complete description of the scope and definitions.
Changes in relation to the 2007 specifications
There are no changes in relation to the 2007 specifications.
Purchasing requirements – Workstations
Requirements conform to Energy Star specifications effective from 20 July 2007.
The requirements apply to computers which are sold as workstations and conform to Energy Star’s definitions for workstations. Power consumption and times are the maximum permitted for energy efficient equipment.
Notes and additional definitions – Workstations
(1) Typical consumption calculated as: 0.1 x power in Standby + 0.2 x power in sleep + 0.7 x power in on mode at idle.
(2) Maximum power as measured in tests per Energy Star test methods.
(3) Number of installed disk drives on workstation.
(4) Computer must switch off separate or built-in monitor within 15 minutes of user inactivity.
(5) Internal or external power supplies must be energy efficient, e.g. minimum 80% efficiency for internal power supplies (at 20%, 50% and 100% load under maximum power output), and conform to the Trust’s requirements for external power supplies.
ENERGY STAR Program Requirements for Computers: Version 4.0 provides a complete description of the scope and definitions.
Good advice on purchasing and operating equipment
Read more about AutoPowerOff plug banks, and where to buy them.
See the electricity consumption on the energy declaration, which suppliers in the Trust’s voluntary agreements display in their advertisements, technical data, etc.
See product lists of computers from suppliers who have signed a voluntary agreement with the Trust stating that they have fulfilled the requirements for energy efficient purchasing.
Read the Trust’s 2008 Interior Layout Guidelines (in Danish) with good advice on organising and equipping office workspaces.
Types of computers:
- Personal computers: standard desktop and notebook computers for office and home use.
- Workstations: more powerful computers for use on demanding tasks such as large applications, video editing, etc.
Requirements conform to Energy Star specifications effective from 20 July 2007.
| Equipment type | On (1) Watt | Sleep (2) Watt | Standby (3) Watt | Delay before sleep (minutes) | Other requirements |
| Desktop computers(4) | |||||
| Category A (5) | 50,0 | 4,0-4,7 (10) | 2,0-2,7 (10) |
30 |
(11)(12) |
| Category B (6) | 65,0 | 4,0-4,7 (10) | 2,0-2,7 (10) |
30 |
(11)(12) |
| Category C (7) | 95,0 | 4,0-4,7 (10) | 2,0-2,7 (10) |
30 |
(11)(12) |
| Notebook computers | |||||
| Category A (8) | 14,0 | 1,7-2,4 (10) | 1,0-1,7 (10) |
30 |
(11)(12) |
| Categoyi B (9) | 22,0 | 1,7-2,4 (10) | 1,0-1,7 (10) |
30 |
(11)(12) |
The requirements apply to standard types of personal computers connected to mains electricity, including types with external power supplies, and types that can operate on charged batteries. Power consumption and times are the maximum permitted for energy efficient equipment.
Notes and additional definitions – Personal computers
(1) On is the idle mode with the computer running the operating system, etc., but excluding user activity. Monitor is switched off on integrated and notebook computers.
(2) Sleep mode is a power saving mode which the computer (but not server) automatically enters after a period of inactivity, and ‘wake’ facility which quickly allows programmes and documents stored in memory (RAM) to be recalled.
(3) Computer is in Standby (off mode) when the user switches off in the normal way via the operating system.
(4) Includes integrated computers with monitor, smaller desktop-derived servers and game consoles.
(5) Category A: Standard types of desktop office and home computers which are not in category B or C.
(6) Category B: Powerful computers with high-performance multi-core processor(s) and minimum of 1 gigabyte of system memory.
(7) Category C: Powerful computers with high-performance multi-core processor(s), and graphic card (graphics processor with minimum of 128 MB of dedicated memory), and with 2 out of 3 of the following attributes:
- Minimum 2GB RAM in system memory
- TV tuner and/or video recorder with HD (High Definition) option
- Minimum 2 disk drives
(9) Category B: Powerful notebook computers with high-performance graphics card (graphics processor with minimum of 128 MB of dedicated memory).
(10) The highest level requires additional functionality for network card (WOL: Wake on LAN, which enables switch on from a network).
(11) Computer must switch off separate or built-in monitor within 15 minutes of user inactivity.
(12) Internal or external power supplies must be energy efficient, e.g. minimum 80% efficiency for internal power supplies (at 20%, 50% and 100% load under maximum power output), and conform to the Trust’s requirements for external power supplies.
ENERGY STAR Program Requirements for Computers: Version 4.0 provides a complete description of the scope and definitions.
Changes in relation to the 2007 specifications
There are no changes in relation to the 2007 specifications.
Purchasing requirements – Workstations
Requirements conform to Energy Star specifications effective from 20 July 2007.
| Equipment type | Typical power consumption Watt | Delay before sleep (minutes) | Other requirements |
| Workstations | 0.35 x (maximum power (2) + 5 x no. of disc drives (3)) |
30 |
(4) (5) |
The requirements apply to computers which are sold as workstations and conform to Energy Star’s definitions for workstations. Power consumption and times are the maximum permitted for energy efficient equipment.
Notes and additional definitions – Workstations
(1) Typical consumption calculated as: 0.1 x power in Standby + 0.2 x power in sleep + 0.7 x power in on mode at idle.
(2) Maximum power as measured in tests per Energy Star test methods.
(3) Number of installed disk drives on workstation.
(4) Computer must switch off separate or built-in monitor within 15 minutes of user inactivity.
(5) Internal or external power supplies must be energy efficient, e.g. minimum 80% efficiency for internal power supplies (at 20%, 50% and 100% load under maximum power output), and conform to the Trust’s requirements for external power supplies.
ENERGY STAR Program Requirements for Computers: Version 4.0 provides a complete description of the scope and definitions.
Good advice on purchasing and operating equipment
- Choose notebook computers
These typically consume less than half as much current compared with desktop computers.
- Choose computers with the lowest power consumption costs over their lifetime
The most efficient cost less than half as much to run as the most inefficient. Check lifetime running costs on the product list. - Computers with external power supplies should comply with the requirements for power supplies.
- Use an AutoPowerOff plug bank that automatically switches off any connected equipment (e.g. monitor, printer, etc.) when the computer is switched off or after a period of inactivity. Read more about AutoPowerOff plug banks.
- Make sure that computers and monitors are programmed to switch to sleep mode after 5 to 30 minutes of inactivity using the operating system’s ‘Control Panel’ power management options. Wherever possible, use special server software that can close down a computer when it is not in use on a network. Read more.
- Make users aware that they need to remember to switch off computers before they go home.
- Remember that notebook computer docking stations have standby power and use extra current when powered up.
Read more about AutoPowerOff plug banks, and where to buy them.
See the electricity consumption on the energy declaration, which suppliers in the Trust’s voluntary agreements display in their advertisements, technical data, etc.
See product lists of computers from suppliers who have signed a voluntary agreement with the Trust stating that they have fulfilled the requirements for energy efficient purchasing.
Read the Trust’s 2008 Interior Layout Guidelines (in Danish) with good advice on organising and equipping office workspaces.
Page last updated 06.10.2008