Power From a Distance

The prospect presents a difficult choice between convenience and energy efficiency. The greater the distance between the power source and the gadget, the more power is typically lost in the transfer. Replacing power outlets with coils in the wall, for instance, may come at a big cost to efficiency—as much as 50 percent or more, depending on the distance from the outlet to the appliance. The trade-off would surely be worthwhile in a pacemaker or other medical device, but probably not in a toaster or a television. How about a plug-in electric car that didn't have to be plugged in? That might pass muster. Sometimes convenience makes all the difference between a worthy product's success and failure.

© 2008