You might not be able to see it, and it may sound more like some looming threat in a Star Trek episode than mundane daily electrical drain—but phantom energy is a very real hazard to both the environment and your electricity bill. Boasting just about the ugliest batch of nicknames in eco-speak, the phenomenon of phantom energy—or vampire power, wall warts, or phantom load—is the way electronic devices use up power when they're plugged in, even if they're turned off. This happens with just about every device in your home: everything from household appliances like coffeemakers and toasters to cell phone chargers and TVs are usurping energy each and every minute their cords stay in the outlet.

There are plenty of ways you can cut back on vampire power. But before you get started, check out this video to get the lowdown on the phantom menace.

"Did You Know" is a series of green tips and enlightening videos on planetgreen.com