Look around your house for external power supplies – the AC adapters that charge cell phones, cordless phones, modems, computer speakers, baby monitors, tools, and many other devices. They lurk in surprising numbers under your desk, in your garage, behind your TV set, and in your kitchen. ENERGY STAR estimates that the average household has up to ten of these devices plugged in all the time.

Some adapters get warm to the touch, even if they’re not charging a device. These copper-and-iron “energy vampires” are continuously sucking electricity from the wall and burning it off as heat.

When shopping for electronic products, look for external power supplies that are compact and lightweight – chances are they’ll remain cool to the touch when plugged in. These power supplies could save you $3 to $6 over the life of the product and help make a dent in greenhouse emissions.

What about the power supplies I can’t see?