Standby Power and Its Consequences | Electricity | Energy Management

Standby power, also called vampire power, vampire draw, phantom load or leaking electricity, refers to the electric power consumed by electronic appliances while they are switched off or in a standby mode. Some such devices offer remote controls and digital clock features to the user, while other devices, such as power adapter for laptop computers and other electronic devices, consume power without offering any features. This later case is sometimes distinguished as no load power.

Consequences of Standby Power:

Standby power makes up a portion of homes miscellaneous electric load, which also includes small appliances, security systems and other small power draws.

Standby power can be as high as 10 to 15 watts per device and occasionally more. A 2005 study estimates the number of standby appliances in the EU at 3.7 billion. Although the power needed for functions like displays, indicators and remote control functions are 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 22% of all appliance consumption and around 10% of total residential consumption.

Many household appliances are never fully switched off, but spend most of the time in a standby mode. “Many appliances continue to draw a small amount of power when they are switched off. These “phantom” loads occur in most appliances that use electricity, such as VCRs, televisions, stereos, computers and kitchen appliances. This can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance”.

Heat Generated by Standby Power:

Standby power can heat a room, potentially requiring more power to cool it in hot weather, but less power to warm it in cold weather.

Fire Risks due to Standby Power:

The risk of fire from devices in standby mode is debated. There are reported cases where televisions have caught on fire in stand-by mode.

The contributing factors for such fires include:

i. Humid environments.

ii. Lightning storms.

iii. Age of the appliance.

A modern HD LCD television may use 1W or less when in standby mode, compared to 80-125 W during operation.

Devices and functions that can consume standby power:

i. Power supplies, transformers and inefficient electronic devices.

ii. VCRs, DVD players and most audio systems.

iii. TVs, home cinema suites and set-top boxes.

iv. Microwave ovens.

v. Computers, digital monitors and printers.

vi. Air-conditioning systems with remote control.

vii. Devices with a stand-by light or clock.

viii. Power adapters (sometimes referred to as wall warts), whether they are powering a device or not.

ix. Most home video game consoles.

Reducing Consumption of Standby Power:

The simplest way to reduce standby power consumption is to unplug unused devices. Another method is to plug them into a switchable power bar or surge protector with multiple sockets and a real off switch, then switching the power bar on and off as needed.

Another alternative is to consider buying energy saving devices or devices that offer a real off switch. Identifying a real off switch can be difficult though, as even devices with a hardware off switch, e.g., TVs, often still do have standby consumption if not taken fully off energy supply.

Replacing battery-powered devices, such as cordless phones or rechargeable razors with corded alternatives not only cuts down on the standby power required to charge the battery, but also reduces energy, lost in battery charging and discharging inefficiencies. Many devices use standby power to retain configuration setting and unplugging them will cause these settings to be lost either immediately or shortly after.

Switching devices on or off can be automated. Timers can be used to turn off standby power to devices that are unused on a regular schedule. Switches can turn the power off when the connected device goes into standby or that turn on/off other outlets when a device is turned on or off are also available.

Switches can turn on/off based on activity sensors. Home automation sensors, switches and controllers can be used to handle more complex sensing and switching. Standby power consumption of some computers can be reduced by turning off components that use power in standby mode.

For instance, disabling Wake-on-LAN wake on modem, wake on keyboard or USB may reduce power when in standby. Unused features may be disabled in the computer’s BIOS setup to save power.

Sometimes certain appliance functions do require small amounts of electricity include:

i. Maintaining signal reception capability (for remote control, telephone or network signal).

ii. Monitoring temperature or other conditions (such as in a refrigerator).

iii. Powering an internal clock.

iv. Battery charging.

v. Continuous display.

Good design can make the power requirements for these functions very low (but not yet zero).