What is Standby Power?
Standby power refers to the electric power consumed by electronic appliances while they are switched off or in a standby mode. Lawrence Berkeley National Laboratory (LBNL) has defined standby power as “Standby power is the power used while an electrical device is in its lowest power mode.” Devices such as a TV or a microwave oven offer remote controls and digital clock features to the user when in standby. Other devices, such as power adapters for laptop computers, tablets and phones consume power without offering any visible features when in standby mode. These and many other devices are users of standby power.
Why is Standby Power Important?
The standby power of household electronic devices is typically very small, but the sum of all such devices within the household becomes significant. Standby power makes up a portion of homes offices and factories’ steadily rising miscellaneous electric load, which also includes small appliances, security systems, and other small power draws.
For example a typical microwave oven consumes more electricity powering its digital clock than it does heating food. For while heating food requires more than 100 times as much power as running the clock, most microwave ovens stand idle—in “standby” mode—more than 99% of the time.
Standby power is typically 1 or 2 Watts for a household appliance, less for computing devices. Although the power needed for functions like displays, indicators, and remote control functions is relatively small, the fact that the devices are continuously plugged in, and the number of such devices in the average household means that the energy usage can reach up to 22 percent of all appliance consumption, and 5 to 10 percent of total residential consumption (see the references for the latest information).
The costs of standby power are:
- Personal (around $100 each year per USA household).
- In wasted electricity generation and transmission infrastructure.
- Political in terms of energy security by contributing to energy imports. (See the U. S. EISA 2007 Energy Independence and Security Act that minimizes standby power for federal procurements).
- Global (an estimated 1% of C02 emissions are due to standby power).
Many programs are already in place to reduce standby power including ENERGY STAR and the EU Eco Directive. The scope of these programs continues to grow and the level of standby power in Watts necessary to achieve compliance steadily falls. For example the European Community (EC) mobile device charger 5-star rating requires a standby power consumption of less than 30mW.
Topics in this primer include:
- How to Measure Standby Power
- Making Measurements to IEC62301 Ed.2:2011 and EN50564:2011
- Tektronix Solutions
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