Plug In to Greener Computing


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Plug Into Greener Computing
Plug Into Greener Computing
LCD monitors are more efficient than CRT monitors
This older desktop computer draws 177 W with an LCD monitor. A CRT monitor could bump power consumption to as high as 300 W.
Modern laptops are more efficient than desktop computers.
Modern laptops provide significant computing power with a fraction of the energy requirements of a desktop computer.
Plug Into Greener Computing
LCD monitors are more efficient than CRT monitors
Modern laptops are more efficient than desktop computers.

In the computer world, the last couple of years have seen many changes in basic technologies, attitudes, and approaches, as well as new organizations and initiatives aimed at greening information technologies. From the consumer point of view, the most important changes are big improvements in energy efficiency of most computer components, and improved documentation of energy consumption.

But is low power consumption all that’s needed for a PC to be green? Well, no, even though most computer product advertising would have you believe it. For example, you cannot ignore simple user factors, such as turning the computer off when it’s not in use or using a plug strip to eliminate the phantom loads of many computer products like printers and monitors on standby. The decision to retire an old, less energy-efficient computer and replace it with a newer, faster, more energy-efficient one is not so simple.

The bottom line is that it’s impossible to bring a computer’s eco-footprint down to zero, which is what green really should mean. We can, however, talk about a greener computer.

Setting the Standard

The U.S. Environmental Protection Agency began certifying computers with its Energy Star label in 1992. The first phase of computer energy standards—v4.0—went into effect in July 2007, with the second phase becoming effective this past January.

By earlier Energy Star standards, a computer could be a total power hog when in use. As long as the power in standby mode stayed below target, then it would earn the Energy Star label. The v4.0 criteria include energy-efficiency and power management for computers, and, for the first time, define maximum idle power. The v4.0 requirements do not include any new regulations for external monitors. Revisions to the current standards for monitors (last updated in January 2006) and first-of-its-kind criteria for servers are expected this year.

Energy Star-approved computers fall into three different categories based on levels of intended usefulness (see Energy Star v4.0 Categories table on page 103).

All Ratings Are Not Created Equal

A problem with the new criteria is that each category has different power limits, yet there is only one Energy Star mark. A desktop computer in category A that draws less than 50 W at idle receives the same Energy Star label as one in category B that draws up to 95 W at idle. The lack of distinction can mislead consumers into thinking that all Energy Star computers are equal in their energy savings.

The EPA’s Energy Star marking methodology also suggests that a category C computer’s efficiency should not be compared to that of a category A computer because it offers better computing performance. Following this logic, a desktop computer with 51 W idle in category A will not earn an Energy Star tag, but a model with 95 W idle in category C will.

Careful consumers can, however, do their homework and find the full details of a product on the Energy Star Web site. A list of certified products is updated periodically and available for free download. The key column to examine is “Power in Idle” for each category. Many models will fall into multiple categories—several desktops, for example, appear in all three (A, B, and C). This is because many brands offer various components and accessories for a given model (i.e., from budget CPUs to gamer-ready quad-cores; from the most efficient on-board video cards to power-hungry 3-D monsters). If your goal is to reduce your energy use, look for the lowest idle-power PC that will meet your needs.

Beyond the Star

If you’re trying to choose a more eco-friendly computer, then you need to look beyond the Energy Star label and energy consumption. The Green Electronics Council—a nonprofit program of the International Sustainable Development Foundation—created the Electronic Product Environmental Assessment Tool (EPEAT), an online system designed to help consumers compare and select desktop computers, notebooks, and monitors based on their environmental attributes.

EPEAT is a voluntary, self-policing registry that addresses 51 criteria divided into eight categories, including reduction/elimination of toxic materials, product longevity, end-of-life management, and energy conservation. The registry ranks products as bronze, silver, or gold, according to three tiers of environmental performance.

EPEAT standards were established by consensus among various stakeholders, including representatives from every major PC company. While this voluntary participation helps ensure that EPEAT standards encourage manufacturers to compete on environmental points, a self-certification system relying on the manufacturers’ word puts the rankings into question. Even though the council performs random reviews, there is no verification of each claim. Adding to the ambiguity of the rankings, some of the criteria on the online registration are indicated by check marks only, rather than detailed explanations or numbers.

Even with its shortcomings, the EPEAT is still the most ambitious resource on the purchasing side of green computing. Since its launch in 2006, the registry has grown to include nearly 1,000 products and has become widely recognized as a tool for institutional purchasing. Although the main database contains products geared for educational, business, and government purposes—often computers with larger hard drives and high-end accessories—there are plans to expand coverage of products for personal and home use.

In the next five years, the EPA estimates that the purchase of EPEAT products will result in the reduction of more than 13 million pounds of hazardous waste and more than 3 million pounds of nonhazardous waste, and save more than 600,000 megawatt-hours of energy.

When To Upgrade

Before you retire your old computer prematurely, consider all of the energy, chemicals, and waste that goes into manufacturing a new computer and disposing of the old one. Then, implement energy-saving measures until a new computer is absolutely necessary. However, when it comes to monitors, replacing your old CRT monitor with a new LCD one is almost always a good idea—an old-style CRT can easily draw more than 100 watts, while a newer LCD monitor of the same size can draw less than 30 W.

If a new computer is a necessity, then you should approach the selection process with a skeptical eye for details. Start by examining the Gold-rated products in the EPEAT database. Once you’ve selected some likely candidates, cross-check them in the Energy Star database and choose from the models with the lowest idle power. In general, laptops consume considerably less power and use fewer materials than desktops—but whether they’re greener is open to debate. Because of the added need for compactness, they are often not as robust as desktop models, nor can they as easily dissipate component-harming heat, so they tend to have shorter life spans.

EPEAT and Energy Star certifications are a good starting point, but you should read about the computer manufacturers and follow their names in the news. Only by understanding their practices and keeping tabs on their environmental record will you feel confident about buying their products. Through an informed purchase, you have the power to shape the marketplace.


Mike Chin is a Canadian tech journalist and founder of Silent PC Review (, a resource center for quiet computers. He also runs Eco PC Review (, a Web site dedicated to greener computing.

Green Electronics Council’s EPEAT •

Energy Star •

IT & Environment Initiative •

Computers and the Environment: Understanding and Managing their Impacts, edited by R. Kuehr and E. Williams, 2007, Springer, 300 pages, softcover, ISBN 978-1-4020-1680-6

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