Call it standby power, phantom power or vampire power, but the current drawn by various household electrical devices when they are supposedly “off” can account for up to ten percent of a home’s energy use. Fortunately, there are gizmos available that act as “middle men” between wall outlets and devices, completely shutting off the power supply when the devices are not in use. One of the newest is the OnPlug, which manages to come in at quite a low price point by avoiding the bells and whistles of similar products.

The OnPlug is pretty much just a single-outlet power bar. It has a male plug that goes into a wall socket, with a single female receptacle that receives a household device’s power cord. An on/off switch allows current to flow – or not to flow – through the OnPlug and into the device. When that switch is in the On position and power is going to a device that isn’t in use, an LED on the OnPlug will alert users that it should be turned turned off.

While the US$11 OnPlug isn’t the only product to do what it does, it is one of the simplest and least expensive. The Energenie is probably its closest competitor, and is available in versions that automatically turn themselves off after half an hour, that turn themselves off when the connected device goes into standby mode, that can be turned on and off via a wireless remote, or that have a built-in timer. Definitely handy features, although prices range from approximately US$13 to $21.

One supposed “bell” (or is it a whistle?) that the OnPlug lacks is a ground plug. Although this limits its applications, the company decided that the reduction in the unit’s size was worth the sacrifice – two OnPlugs can fit into one dual wall outlet, a claim that reportedly cannot be made by any other such device.

At this point, however, a logical question to ask might be, “Why not just unplug your devices?”. Well, you can, although OnPlug Innovations’ Gerry Heffernan believes that many people simply won’t go to the extra effort involved in doing so.

“Many of us do not want the bother or the hassle of unplugging,” he told Gizmag. “The elderly find unplugging physically demanding. Sometimes outlets are located in an inconvenient place where bending over to touch off a switch would be easier.” He also noted that outlets are sometimes located in areas such as kitchen counters, where unplugged power cords would be in the way.

The OnPlug can be ordered from Real Goods.