Berkeley Lab Research News


Study Finds ENERGY STAR Office Equipment Could Save $1 Billion per Year

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Allan Chen,

July 29, 1996

BERKELEY, CA -- Personal computers, monitors, printers, faxes and copiers in the Environmental Protection Agency's voluntary ENERGY STAR office equipment program could save U.S. businesses almost $1 billion per year in energy costs by the year 2000, at negligible cost to the consumer.

This is one of the conclusions of a study conducted by researchers in the Energy and Environment Division at Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) for the U.S. Department of Energy. The results of the study are being published in the journal Energy Policy later this year.

This study is part of ongoing research conducted for the US DOE's Office of Building Technologies, State and Community Programs on energy use, energy savings, and reducing pollution in residential and commercial buildings.

To qualify for the ENERGY STAR label, the EPA requires the equipment to reduce power consumption during idle periods. For example, typical monitors use 50-100 watts at full power, but those listed as ENERGY STAR monitors must reduce power use to 30 watts when idle.

The EPA announced the ENERGY STAR Program in 1992 and since then has listed more than 2,000 PCs and monitors as ENERGY STAR-qualified. Over the past few years, the agency has expanded the voluntary program's coverage to printers, copiers, and fax machines.

"Until now, there hasn't been any comprehensive analysis to estimate the possible energy savings from this program," says Jonathan Koomey, Berkeley Lab Ph.D. Staff Scientist and the study's principal author. "Office equipment currently makes up about 7% of total commercial sector electricity use, and it was a large contributor to electricity demand growth for utilities in the 1980s and early 1990s", says Koomey, who worked with a team of analysts to model the energy use of office equipment.

He states further that "the ENERGY STAR program, combined with large declines in total mainframe and minicomputer energy use (caused by the shift to client-server computing), will largely offset growth in office equipment electricity use over the next 10-15 years."

The study examines several scenarios ranging from optimistic to pessimistic. "Benefits from energy saved by ENERGY STAR office equipment depend on assumptions about how rapidly the office equipment market grows, how many devices are shipped with energy-saving features, and how many customers continue to use the power saving features," says Koomey "but in all of the scenarios we examined, the net benefit was large, and the costs to consumers and manufacturers were negligible".

Using the assumptions for the most likely situation, in which half of all PCs, 70 percent of monitors, 90 percent of copiers and 100 percent of printers and fax machines with ENERGY STAR features are "enabled" and effectively save energy, the program saves 11 terawatt-hours (trillion watt-hours or TWh) in the year 2000, which amounts to a $900 million savings for U.S. businesses (all savings expressed in 1995 dollars). This grows to 17 TWh of electricity saved per year by 2010 ($1.4 billion annual savings).

The energy saved in 2010 represents the output of three large (1,000-MW) power plants, and is equivalent to the electricity used by 1.7 million households in one year. The annual savings in 2010 ranged from 10 TWh in the most pessimistic case to 23 TWh in the most optimistic case."

"What's important to remember," says Koomey, "is that these benefits are delivered to the consumer at negligible cost to the purchaser. There is little difference in the costs of equipment with or without energy saving features."

To develop their model, Koomey and colleagues had to gather information on the number and types of office equipment in commercial buildings throughout the U.S., as well as how much energy is used by each type of equipment. The model also uses information on the projected growth rate of office equipment ownership by type, equipment lifetimes, office occupancy, and equipment usage.

The study also investigates the potential impacts of an "Advanced Technology" scenario, where energy saving innovations are assumed to be pursued without regard to cost. This scenario characterizes the outer bounds of what is possible given current technology but does not assess whether these technologies are economically justified. The results indicate that there is a technical potential for significant savings even beyond the ENERGY STAR Most-Likely case.

To read the executive summary of this report on the World Wide Web, go to

The Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified research and is managed by the University of California.