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If you're in the market for a new computer, you're far from alone. Nearly 30 percent of U.S. consumers will replace their computers this year in search of more speed, memory and features as technology evolves at breakneck speed. It's estimated that nearly 70 million computers were sold in the U.S. in 2007. Consider that a single computer requires 1.8 tons of raw materials during production, and buying a greener machine becomes obvious.

But how can you tell a green machine from one that isn't?

What To Look For

EPEAT

So far, the Electronics Products Environmental Assessment Tool (EPEAT), created by the Environmental Protection Agency and the nonprofit Greener Electronics Council, is the easiest way for people to distinguish green computers from their competitors. The tool rates desktops, laptops and monitors based on 51 criteria including toxics reduction, recycled content, energy efficiency (being Energy Star–rated is required), ease of recycling, product longevity, the manufacturer's takeback and recycling program, and packaging. All computers are required to meet 23 mandatory criteria, and "Gold" rated computers meet the most optional criteria.

Unfortunately, finding an EPEAT-rated computer can be difficult. Developed to help aid in federal green purchasing programs, most EPEAT computers are designed for businesses, and even the few consumer products that are EPEAT rated aren't always advertised as such by manufacturers. EPEAT does make searching easy, though, in their online database at www.epeat.net.

Energy Star Rating

If your search for EPEAT-rated products turns up nothing, buy Energy Star rated machines. These may not be free of toxic chemicals, but they do use substantially less energy. Computers and laptops use 20 to 50 percent less energy (depending on size, memory capacity and processing speed) than their non-rated counterparts, and monitors use 20 to 60 percent less energy.

If the EPEAT and Energy Star-rated computers still don't meet your needs, buy a laptop, which uses substantially less energy, contains fewer chemicals and uses fewer resources during production than larger desktops. It can be harder to upgrade a laptop than a desktop, so find one that allows for easy access to memory cards and other upgradable parts.