New Standards Cut “Vampire” Energy Waste

Posted on June 3, 2013 by
Andrew deLaski

U.S. Energy Secretary Ernest Moniz announced new national energy efficiency standards for microwave ovens on Friday that will take a bite out of standby (or “vampire”) power. Just as important, completion of this long-delayed rule offers hope that the White House and the Department of Energy (DOE) are ready to put an end to the delays that have been plaguing new efficiency standards over the past couple of years.

First, let’s talk about microwaves.  With a few simple changes, energy wasted by microwaves can be reduced to almost zero. A typical mmicrowaveicrowave spends only about 70 hours heating up food over the course of a year. For the remaining 8,690 hours (99% of the time), the microwave consumes energy continuously to power the clock display and the electronic controls. But some microwaves waste more energy than others. The microwaves that waste the most energy in standby mode consume about 4 watts of standby power, which adds up to about 35 kilowatt-hours (kWh) over the course of a year. The new efficiency standards, which will take effect in 2016, will limit standby power consumption to just 1 watt for most microwaves.

Given that 95% of households have a microwave, the small savings from each microwave add up. On a national level, DOE estimates that the new standards for microwaves sold over 30 years will save consumers $3.4 billion and will reduce electricity consumption by about 69 billion kWh, or an amount equal to the annual electricity use of about 6 million U.S. homes.

One simple step to reduce microwave vampire power involves changing the cooking sensors that are found in some microwaves, and which tell the microwave when to shut off during a cooking cycle. Traditional cooking sensors consume about 1-2 watts of power continuously because they need to be kept warm. A newer type of steam sensor provides the same functionality as traditional cooking sensors, but consumes zero standby power. Other simple changes to reduce standby power include improving power supply and control board efficiency.

The microwave oven is just one of the products for which efficiency standards have reined in vampire energy waste. Since a 2007 energy law required DOE to include standby energy use in new efficiency standards, the department has addressed vampire energy use in six products including clothes washers, clothes dryers, dishwashers, room air conditioners, central air conditioners, and furnaces.

The same 2007 energy law established the first-ever national standard for external power supplies. Since then, you may have noticed that the power supplies that have come with your latest cell phone and other gadgets are less bulky and lighter. They also do not get as warm to the touch as older power supplies, which means they are wasting less energy.

Later this year, DOE should complete updated power supply standards that will save even more. DOE is also working on new standards for battery chargers---the devices that power everything from portable power tools to cordless phones to electric toothbrushes. Existing California state standards for battery chargers are already affecting the national market and we expect the national standards to be equal to or stronger than the California energy waste limits. Since battery chargers consume power even when the device is not charging a battery, these new standards will take another important step towards reducing vampire energy waste.

Which brings us to the other good news in this announcement: The White House and DOE recognize how important improving efficiency is for meeting the president’s energy goals. Deputy Assistant to the President for Energy and Climate Change Heather Zichal blogged from the White House on Friday about how making appliances more efficient will “help Americans keep more money in their pockets …curb pollution and spark innovation …” In announcing the microwave standards, Secretary Moniz declared, “Appliance efficiency standards represent a huge opportunity to help families save money by saving energy, while still delivering high quality appliances for consumers.”

Zichal and Moniz have much more to do. As we described in January, the new microwave standard is one of eight for which DOE missed completion deadlines over the past two years. Before DOE set the microwave standard, the agency finished new transformer standards in April. Another four covering commercial refrigeration and lighting products still await approval from the Office of Management and Budget. The new standards for external power supplies and battery chargers remain under development at DOE along with new industrial motor standards. However, with a strong new microwave oven standard now complete, it looks like this administration is starting to get back on top of its game for improving energy efficiency.

Joanna Mauer contributed to this blog post