Spare a thought for how you charge your computer – or phone, or coffee pot, for that matter. That lowly power supply that converts household electric current from a wall outlet into lower voltage direct current (DC)? Billions of these devices are in use worldwide at any given time. They’re useful but also incredibly wasteful. Much of the energy they draw from the wall goes up in smoke – in heat, actually – even if they’re not charging anything. In fact, it is estimated that the wasted energy for such external power supplies amounts to about 4% of total electricity usage in the US
That is why regulatory agencies around the world are imposing new restrictions on how these devices are designed. On Feb 10, 2016, new regulations on the energy efficiency of external power supplies, drawn up by the US Department of Energy, will go into effect. Called Level VI, these regulations mandate minimum efficiency regulations for a wider range of external power supplies and significantly lower the amount of power that can be consumed at rest – in no-load conditions. Read more..Efficiency Standards for External Power Supplies.
The effort to curb energy waste in power supplies goes back two decades. In the early 90’s, it was estimated that in the United States alone, there were more than one billion external power supplies, mostly based on linear technology, with efficiencies as low as 50%. And, they would still draw power when the application was turned off or not even connected to the power supply (referred to as “no-load” condition). Experts calculated that without efforts to increase efficiencies and reduce “no-load” power consumption, external power supplies would account for around 30% of total energy consumption in less than 20 years. As early as 1992, the US Environmental Protection Agency started a voluntary program to promote energy efficiency and reduce pollution, which eventually became the Energy Star program. However, it was not until 2004 that the first mandatory regulation dictating efficiency and no-load power draw minimums was put in place. This diagram (see Figure 1) demonstrates just how dynamic the regulatory environment has been over the past decade. It also traces the path from the CEC’s 2004 regulation up to the new Level VI standards set to take effect February 2016.
If you’re designing products that use external ac-dc power supplies for the U.S. market you’d better comply, now. And, if you’re selling worldwide, you’d better track what other countries are doing, because everyone is moving to mandatory compliance on energy efficiency. For our handy guide to negotiating this regulatory minefield, click here.