The latest Department of Energy (DoE) energy efficiency requirements won’t be the last. Check out a recent article featured in the November 2017 Issue of Design World Magazine’s Power & Energy Efficiency Handbook which describes a few of the changes in efficiency regulations the power supply industry can expect.
As early as the 1990s studies showed that smaller external power supplies — such as those powering cell phone chargers, game boxes, cordless phones, and so forth — were becoming a major source of energy demand and were growing explosively. It also soon was obvious that the reduction of energy consumption in power supplies sitting idle but connected to power lines was even more important to reducing overall power consumption. Thus began demands that the power supply industry build more efficient power supplies to reduce the waste in energy consumption.
In 2004, California became the first government organization in the U.S. to declare legal energy efficiency requirements, followed by the U.S. government with the Energy Star program, a voluntary but not mandatory requirement for efficiency. When the DoE first came out with its proposal for efficiency standards, the reaction from the power supply industry was enormous and severe. The new standard was to be 88% at 50 to 250 W, with a sliding scale of 85 to 88% between 18 and 50 W, and a maximum no-load input draw between 0.1 and 0.21 W. The previous requirements were also a sliding scale to 49 W, with 80% at 18 W, and 86% at <49 to 250 W, and between 0.3 and 0.5 W at no-load. The biggest changes were expected in the lower powered units, nearly a 10% improvement at 18 W, where factors like voltage drop through the output cable is a fixed loss.