With modern electronics, "off" doesn't really mean off. When you turn off every electrical appliance and light, your meter mysteriously continues to turn.

Devices such as microwaves, DVDs, cable boxes, cordless phones and even newer toasters draw power in order to be ready to turn on instantly and to receive information from remote controls, as well as for functions such as clocks.

The result is that a microwave oven can consume more electricity on this "standby" power than it does heating food. While running the microwave uses much more power, it's usually only for a few minutes a day.

According to the U.S. Department of Energy, on average 25 percent of the power used by home electronics is consumed while they are theoretically off. While the standby power use is small for each electronic device, there are a lot of them out there. Experts estimate that this "phantom load" will soon account for 20 percent of U.S. electricity use.

Most standby power is lost as heat from power supplies (or transformers), the black boxes that change the alternating current from outlets into the lower voltage direct current used by many electronic devices.

Phantom power culprits include devices with remote controls, continuous digital displays and soft-touch keypads. Cordless tools and appliances are convenient, but their chargers do contribute to phantom load. Most chargers continue to draw power as long as they are plugged in, although some newer "smart" chargers can sense when charging is complete.

To reduce this phantom energy use:

• Unplug electronic devices between uses. This is easier if you plug several into a power strip and switch off the power strip. Even easier, there are now power strips and surge protectors that automatically turn off related electronics, such as turning off computer peripherals when the computer is off.
• Unplug battery chargers for devices such as cell phones, cordless drills and laptops after the batteries are charged.
• Look for the ENERGY STAR® label. ENERGY STAR power supplies and battery chargers are more efficient and use less power when off.