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Key Terms and their Definitions

 © 2009-2014
Christian Bachmann

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The following terms are relevant to the understanding of the facts, the discussion and the conclusions. Therefore they are explained concisely below in the way in which they are used in this report. They are not to be considered universally valid.


When equipment is mentioned this usually refers to (a) information and office technology equipment, (b) telecommunications and (c) consumer electronics:

a) computers, monitors, printers, scanners, photocopiers;
b) phones, fax machines, modems, switchboards;
c) television sets, video equipment, radio-cassette recorders, hifi-stereo sets.

However, these categories cannot be clearly distinguished. For example, the same technology and components are used partly in printers, copiers and fax machines.


Usually this refers to electric energy, i.e. to the direct energy consumption of equipment. Attention should also be directed to the 'indirect' energy consumption of the infrastructure (air-conditioning system, uninterruptible power supply). This consumption is almost equal to the direct energy consumption [15]. Also the energy needed for production of hardware and materials need to be added.

Power management

Controlling the power consumption of a piece of equipment by means of intelligent circuits and/or software, which according to requirements switch individual modules on and off. The energy requirements of a piece of equipment depends on the time it takes to become operational. Immediate availability (stand-by) requires the highest energy consumption of non-operating equipment, lower energy consumption (sleep mode) is usually coupled with waiting periods. Therefore power management is also time management.


Readiness of a piece of equipment. The equipment has reached operating conditions, but it is not operating. All functions are active to the degree required for immediate operation. Depending on the individual piece of equipment the energy consumption in the stand-by mode can be considerable. In the case of equipment which is rarely used it often happens to be higher than when it is actually operating. Therefore there is a trend to define operating states with lower power consumption (for example the sleep or energy-saver mode).

Energy-saver mode

The condition that exists when the machine is not ing, has previously reached operating conditions but is consuming less power than when the equipment is in stand-by mode. There are different terms for different modes of equipment using less power than in stand-by: low stand-by, sleep mode, deep-sleep mode. In these modes parts of the equipment presently not needed are switched off. However, the equipment is ready to become fully operational when it receives certain signals (eg pressing a key, moving the mouse, signal input).

Market-pull strategy

Controlling the market by intensifying demand. This is the given strategy to reduce the power consumption of equipment since there is no stimulus for manufacturers to exploit technologies which are available beyond the frame dictated by comfort and performance. A pull strategy can only be successful if one succeeds in arousing and focusing the interest of large groups of buyers.

Testing procedures

A defined procedure accepted by both manufacturers and controlling organisations for measuring the power consumption of equipment at various operating states.


In this report this refers to values concerning power consumption or power input which have to be met by equipment in order to obtain a stamp of quality or to be admitted on the market under tighter rulings. There is a testing procedure for each type of equipment for which a standard is issued.

Target values

Similar to standards, except the controlling organisation does not lay down any mandatory values for power consumption; it issues only recommendations. Could also be applied in a soft transitional phase until standards are introduced.

© Christian Bachmann