“Energy efficiency” used to refer to electronic designs that didn’t waste power through inefficient power conversion methods, or excessive standby power consumption. Now, efficient use of energy both includes and goes beyond these two givens with the addition of an energy-aware network of smart devices that combine intelligence, sensors, and communication capability. This collection of technical articles highlights some of the designs used by the smart meter, lighting, and solar industries to make our electronics-hungry world more energy-efficient.