In today’s world of high-tech electronic devices, “off” doesn’t really mean off anymore.
Most televisions slowly sip electricity while waiting for someone to press the “on” button. They use energy to remember channel lineups, language preferences, and the time. DVD players, DVRs, and cable or satellite boxes also use energy even when they’re supposedly off.
Quiet and unnoticed, the electricity being used by entertainment devices, computers, printers, and phone chargers are commonly called “parasitic loads,” “phantom loads,” or “energy vampires.” The electricity used by these sneaky “not really off” items can add $70 to your electric bill every year.
Ordinary power strips, which have been around for decades, make it easy to turn off groups of devices with one switch. Many also protect sensitive devices against power surges. But today’s household electronics jumble requires a smarter approach to make sure power stays on for certain devices, but is turned off for the items that don’t need electricity all the time.
Most smart strips feature three outlet colors, each with a unique task. The blue outlet serves as the control, and is ideal for a device that can be turned completely off when not being used. Things plugged into the red outlets stay on. Electricity to these receptacles never cuts off, making them perfect for satellite boxes or other devices that truly need constant power.
The remaining outlets, often neutral or green in color, are sensitive to current flowing through the blue outlet, so turning off that item also cuts power to these items. Some smart power strips can be made even smarter with timers or occupancy sensors that determine when to cut power to various devices.
BRIAN SLOBODA/Cooperative Research Network