A few days ago, the U.S. Department of Energy (DOE) announced a new efficiency standard for microwave ovens. Microwave ovens have always been covered by the Energy Policy and Conservation Act of 1975 (EPCA) and more recently, the Energy Independence and Security Act (EISA 2007), but this is the product’s first federal efficiency standard. Product classes covered include microwave-only ovens /countertop combination microwave ovens and built-in and over-the-range combination microwave ovens.
The new standard only focuses on the energy wasted by microwave ovens when they are not cooking our food (i.e. in standby mode)*. While one might expect that an oven not in use should consume very little energy, testing of available units revealed that standby power consumption for microwave-only and countertop combination ovens ranged up to 4.7 W and built-in and over-the-range combination ovens consumed up to 9 W of power. The features driving the high levels of standby power included cooking sensors, display technologies (including clocks), and control boards used for turning power off to components during standby.
The new power levels (shown below in Table 1) become effective in mid-2016. The DOE estimates that consumers will save nearly $3 billion on their energy bills through 2030 with ovens meeting the new levels. Over the next 30 years, the reduced carbon pollution will be equivalent to taking over 12 million new cars off the road for one year.
Table 1. Maximum Allowable Standby Power for Microwave Ovens (Source: U.S. DOE)
|Product Group||Maximum Standby Power|
|Microwave-Only Ovens and Countertop Convection Microwave Ovens||1.0 W|
|Built-In and Over-the-Range Convection Microwave Ovens||2.2 W|
For more information, visit the DOE Appliance and Equipment Standards rulemaking page.
*The DOE previously determined that an active mode standard was not warranted. (Federal Register – 74 FR 16040; April 8, 2009M)