What to Look For

EnergyStar Ratings

The Energy Star program, run by the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA), evaluates a wide range of consumer products for their energy efficiency, awarding the EnergyStar label to those that top the list.

In July, EPA announced a new class of EnergyStar ratings for desktop computers and laptops. The standards were set so that only the most efficient 25 percent of today's computers would be able to qualify for EnergyStar status. EnergyStar-approved computers will, on average, be 30 percent more efficient than those that don't make the cut.

Laptops that qualify for EnergyStar 5.0.approval can be in one of three categories, depending on the computational power of the laptop. The categories are based on the average number of kilowatt hours (kWh) a computer consumes over a typical year of use. kWh is the number of watts of electricity that an electronic device uses in an hour. A 50-watt laptop, for instance, used for an hour, has consumed .05 kWh.

Category C, designed for those powerful laptops with two or more cores per processor, designates laptops that use computers use 88.5 to 543 kWh over a year. Category B laptops, those with a separate graphics processors for rendering displays, consume 53 kWh to 41 kWh; and Category A is for all other laptops that use 40 kWh or less.

EnergyStar also measures the efficiency of the computer's power supply (which converts alternating current into direct current) as well as how much energy the unit leaks when not being used.

EPEAT Ratings

While EnergyStar has helped consumers identify more energy-efficient machines, it doesn't address the issue of recyclability.

EPA and the nonprofit Greener Electronics Council have created the Electronic Products Environmental Assessment Tool (EPEAT) as way to gauge how environmentally friendly electronic components are, in terms of materials they are built from and the manufacturer's recycling plans.

EPEAT requires that computer manufacturers meet 23 mandatory conditions, such as providing a statement of how much recycled material was used in the product and providing an additional optional three-year warranty to keep the laptop in use longer. EPEAT also has 28 additional criteria, such as requiring the laptop be built from at least 90 percent recyclable materials and that that laptop use batteries that are entirely free of lead, cadmium and mercury. Bronze status is awarded to products that meet all mandatory requirements, silver status goes to products that meet the mandatory requirements, plus 14 of the optional criteria, and gold rated means the machine meets all mandatory requirements and at least 21 optional criteria. All EPEAT-certified products must also be EnergyStar approved.

Restriction of Hazardous Substances (RoHS)

In Europe, laptops must meet standards for not exceeding the maximum level of toxic substances, such as lead, cadmium and mercury. Meeting RoHS is one of the requirements for basic EPEAT certification.

Greening Efforts of Laptop Manufacturers

Spending dollars on the greenest models sends a message to computer makers. The message seems to be sinking in with laptop makers, who are starting to produce models that are energy efficient and built from recycled material, or at least made from material that could be recycled. Check the manufacturers' Web sites for details of their efforts. Companies such as Apple and Dell have pages dedicated to explaining their efforts at building more eco-friendly computers.

Shopping Tips

• Evaluate your needs: What you plan to use your computer for will help you purchase the most efficient one for your needs. If you plan on using the device mostly for simple tasks such as checking e-mail, surfing the Web, or watching a DVD, then take a look at netbooks, which not only cost less, but have processors that sip less energy. These tasks don't require a lot of computational muscle, so a lower-power processor would run them without problem. If you use resource-intensive applications, such as photo editing software, then a laptop with a dual-core processor would be more appropriate. And if you plan to use the unit in extreme environments such as use in moving vehicles or outdoors in damp climates or extreme temperatures, then paying for a rugged model may be the greenest choice because they'll last longer.

• Look for low-power components: The computer industry is starting to learn that in order to make more power-efficient computers, they need to be made with more power-efficient components. Solid-state drives, although more expensive, consume less power than standard hard-drives (and are a lot more rugged and can be faster as well). Also, look for computers with the new generation of low-power chips. Chips consume up to half of all the power a CPU draws. Intel has released a line of low-power chips, code-named Atom, that consume less power and provide nearly the same performance, as has Via, with its Nano line of processors that are used in numerous netbooks. Look for the names of these processors in the specification sheets.

Usage Tips

• Deploy stand-by mode: Computers can be configured to go into sleep, standby, or hibernate mode if left unused after a period of time. EPA recommends having them go into such a mode after 30 to 60 minutes of inactivity, though setting it for a shorter period of time saves even more energy. Using the sleep or hibernate mode can cut an average computer's power consumption by half, the agency estimates. Keep in mind hibernation is not the same as running a screen-saver, which does not, contrary to popular belief, save any energy. EnergyStar offers a free program called EZ Wizard that walks you through the process of setting up power-management features in Microsoft Windows XP. Power-saving software is available for the Macintosh as well, through the Power Save Mac software.

• Extend laptop lifetime: Does your current laptop do everything you need? If so, consider holding onto it for a while longer. These days, even models five or six years old can execute almost all currently offered software. Getting more life out of your laptop not only saves you money but makes more efficient use of the materials that have already been deployed. If you do get a new laptop, and your old model still works, consider donating it to a non-profit, such as Computers with Causes, which refurbishes computers for educational institutions. Or donate to someone else in need of a computer.