Small loads that add up
Many devices keep drawing power when they look switched off: the TV waiting for its remote, the cable or satellite box, the game console set to instant-on, the printer, the microwave clock, the coffee maker and the chargers left in their outlets. Each one draws only a few watts, but they run 24 hours a day, every day of the year. A 2015 study of California homes by the Natural Resources Defense Council found that these always-on loads averaged nearly a quarter of household electricity use.
The calculation
- Total standby power = number of devices × average watts
- Energy per year = total watts × hours per day × 365 ÷ 1,000, in kWh
- Cost per year = kWh × price per kWh
- Possible saving = cost × share of devices you could switch off completely
Example
A household has 10 devices that draw an average of 5 W each on standby for 20 hours a day, with electricity at $0.17 per kWh:
- Total standby power: 50 W
- Energy: 50 × 20 × 365 ÷ 1,000 = 365 kWh a year
- Cost: $62.05 a year
- Switching off 70% of that load saves about $43 a year, or $434 over 10 years
Finding the biggest culprits
A plug-in power meter costs little and shows exactly what each device draws. Typical results:
- Modern TVs, phone chargers and appliances: often under 0.5 to 1 W
- Cable and satellite boxes, DVRs: 10 to 25 W, nearly the same as when in use
- Game consoles in instant-on or rest mode: 2 to 15 W
- Desktop computers in sleep, audio receivers, subwoofers: 2 to 10 W
How to cut it
- Use a power strip with a switch, or an advanced strip that cuts the peripherals when the TV or computer turns off.
- Turn off instant-on and quick start modes in console and TV settings.
- Unplug chargers and devices you rarely use.
- When replacing equipment, choose ENERGY STAR models, which have strict standby limits.
Keep devices that need power to work, such as alarms, medical equipment, routers you need at night and fridges, on permanent power.