Guide 05 / 10
Standby power: small each hour, long in use
Estimate the energy drawn by devices that stay connected while they are not in active use.
Recognize standby mode
Some products still draw power when they appear off, perhaps for a clock, receiver, or quick start. This is standby power. The amount varies by model and mode. An online figure for one device should not be applied to every product.
Use the right number of hours
If measured standby draw is 2 W for 20 hours a day over 30 days, energy is 2 × 20 × 30 ÷ 1,000 = 1.2 kWh. Do not count 24 standby hours if the device is active for four; estimate the modes separately and add them. A multi-day measurement is better when practical.
Keep function and safety in mind
Disconnecting a device may remove settings or a function you need. Do not switch off a safety device or an essential service for a small estimated saving. Follow product instructions and consider your household's needs.