As electronic products have become increasingly energy-efficient, the improvement gap between successive generations has narrowed. Home electronics and appliances are nearing the point of diminishing returns on incremental efficiency improvements, and the discussion about efficiency is shifting to include time, as well as quantity, of usage.

The federal government's goal of transforming the aged electrical grid into a fully integrated and interactive "Smart Grid" adds complexity to the issue of managing home energy use. Products that interact and communicate with the Smart Grid will play an important role, if stakeholders can come to a consensus on common standards and protocols for Smart Grid-compatible products and systems. (For more on Smart Grid-compatible products, read CUSTOM HOME's latest Digital Home column, a Web-exclusive to the May/June 2009 issue.)

Major home appliances account for nearly 20 percent of an average home's energy use, according to the U.S. Department of Energy, and much of that usage occurs during peak demand periods for which local utilities are finding it increasingly difficult and costly to supply power. Some electrical utilities are considering, or have implemented, time-of-use pricing structures for their customers, with higher rates for peak usage periods. Consumers who have access to their home energy use and electricity rate periods data are empowered to make more intelligent choices about how they will interact with the grid, says Katherine Hamilton, president of The GridWise Alliance, a Washington, D.C.-based public/private consortium of energy, automation, equipment, and utility stakeholders. "The industry is going to evolve pretty rapidly to develop tools to allow consumers to make and implement those decisions," she explains.

Some major-appliance manufacturers are developing efficient products that allow consumers to easily monitor their energy use and shift their demands to off-peak periods by automatically interacting with the grid. Such "smart" appliances aren't an altogether new idea, but the focus has shifted from the kind of intelligence that allows a refrigerator to track its contents and generate grocery lists, for example, to the kind of intelligence that allows a refrigerator to respond to messages from the utility signaling a peak pricing period by delaying its defrost cycle.

Two of the largest manufacturers of major home appliances in the United States, Whirlpool Corp. and GE Consumer & Industrial, have initiated programs to develop Smart Grid-compatible, demand-responsive products. "If we can smooth out the power demand peaks or shift them to some degree, then overall energy generation and use would be more effective," says Henry Marcy, vice president of technology for Whirlpool.

In October 2008, GE began a pilot test program of its first demand-response appliances, partnering with Louisville Gas & Electric Co. (LG&E), which has implemented time-of-use pricing structures, and 50 of its customers. Homes were outfitted with complete suites of demand-response appliances and smart meters that cooperate to receive signals from the utility broadcasting the start of peak pricing periods. The signal sets off the appliances' pre-programmed energy conservation programs, which either delay the start of cycles or operate cycles at reduced wattages. A display screen allows program participants to see when peak pricing is in effect, enabling them to make more intelligent choices about when to use their appliances.

Participating in GE's Smart Meter/Appliances pilot program, Mark and Dana Brian use the monitor to track energy use of GE Demand Response appliances, which work with a "smart" utility meter. Courtesy of GE Consumer & Industrial

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