Smart circuit-breakers for energy-efficient homes

Let there be light IN THE future, homes will use electricity much more sensibly than they do now: turning the lights off automatically when no one is around; adjusting the heating regularly to suit a householder's daily routine; making sure the electric car is charged up using off-peak rates; even drawing power from the car's battery in the event of a grid outage. A variety of plug-in devices can already do some of these things. Yet lurking in every home, usually in a dark cupboard or down in th...