Standby power cost

What standby power is

Many devices keep drawing a small amount of power when they are not in use, for example to listen for a remote control, keep a clock or display running, stay connected to a network or keep a charger ready. Small amounts add up because they run for many hours a week.

How the calculation avoids double counting

The hours plugged in per week include the hours in use. The calculator counts in-use power only for the hours in use, and standby power only for the remaining plugged-in hours: standby hours = hours plugged in − hours in use. A week has 168 hours, so plugged-in hours cannot exceed 168, and they cannot be fewer than the hours in use.

Finding the standby power

• Product specifications sometimes list standby or networked standby power in watts.
• A plug-in energy monitor can measure it, although some monitors are not accurate for very small loads.
• To estimate standby alone, enter 0 for the power when in use.

Examples

An illustrative television using 100 W for 4 hours a day, 7 days a week, with 1 W of standby and plugged in all week, uses 146 kWh a year in use and 7.3 kWh on standby (140 standby hours a week). At an illustrative $0.20 per kWh, that is $29.20 in use and $1.46 on standby. A device drawing 5 W on standby around the clock uses 43.8 kWh a year, or $8.76 at the same price.

Reducing standby use

Switching devices off at the wall or with a switched power strip stops standby use where that is safe and convenient. Some settings, such as quick start or network standby modes, can increase standby power. Some devices, such as routers or anything that needs updates, may need to stay powered.