U.S. Department of Energy - Energy Efficiency and Renewable Energy
Federal Energy Management Program
Going Beyond ENERGY STAR® to Save Energy When Purchasing Computers
March 31, 2005
Desktop computer energy use is rising fast due to more powerful video cards and microprocessors, and the challenges of enabling power management across networks. Despite this increase in energy use, new technological advances and a new utility partnership can help federal buyers take advantage of more efficient computers that minimize energy waste.
The 80 Plus Opportunity
The solution is to buy computers with a more efficient power supply. This simple, silver box is found inside nearly all desktop computer models and is designed to convert high voltage alternating current from the wall outlet into low voltage direct current for use by computer circuitry. The best new designs are more than 80 percent efficient and power factor corrected, often allowing computers that use them to be smaller, quieter, and cooler.
Most current desktop computer power supplies are only 60 to 70 percent efficient, meaning they waste 30 to 40 percent of all the electricity the computer consumes. An 80 Plus compliant power supply allows the typical desktop computer (Figure 1) to drop from 361 kilowatt hours per year to 285 kilowatt hours per year, saving 21 percent of total electricity use across all modes of operation. Most of that electricity is saved during the workday, when electricity costs and cooling loads are usually highest.
To help bring these new power supplies and computers to market, Ecos Consulting has teamed up with the Northwest Energy Efficiency Alliance, Efficiency Vermont, and various California and east coast utilities to create the 80 Plus program (www.80plus.org). The program tests power supplies and computers to identify models that are more than 80 percent efficient and power factor corrected. Participating utilities pay manufacturer incentives of $5 for qualifying desktop computers and $10 for desktop derived servers sold in their service territories. That covers most to all of the extra cost of installing better power supplies, depending on the technology employed.
Demand Efficiency with Model Procurement Language
The success of this effort rests on consumer demands for these more efficient power supplies. Many computer manufacturers will not commit to offering the better power supplies until their largest customers demand them. If federal and state agencies incorporate 80 Plus into their long term procurement specifications, manufacturers will offer the option on key models. This will reduce energy bills and minimize lifecycle cost, saving about $25 over a desktop computer's 4 year life and more than $100 in servers over the same 4 year period.
To make it easy, the 80 Plus program has posted model procurement language on its website. You can add that language to your existing procurement specifications and cut your computer energy use by about 21 percent—if you give manufacturers six months of lead time to respond. They, in turn, will pass those requirements through to their supply chain, buying the more efficient power supplies from them.
How much can you save? If you buy 1,000 computers a year, participating in this program could cut your electric bills by $18,000 after just 2 years, not counting air conditioning savings and the value of improving power quality. But every office uses different types of desktop computers and for different periods of time. To make the calculations easy, the 80 Plus program has posted a procurement calculator on its website. It's a simple Excel spreadsheet that allows you to estimate your savings across the number of computers you buy each year.
Market Realities: Why Buying ENERGY STAR® is Not Always Enough
Computers are often heralded as one of the great success stories of energy efficient labeling and procurement. Since the launch of the first ENERGY STAR® labeling program in the early 90s, computers have been able to drop into a low power sleep mode after a period of inactivity. More recently, FEMP developed a list of computers that meet low standby power guidelines of 2 watts or less (about half of all current models). Federal agencies have been able to tap those "low power mode" energy savings by specifying ENERGY STAR® and FEMP compliance when purchasing computers.
More than 90 percent of the desktop computers currently sold in the U.S. are ENERGY STAR® compliant (see Figure 2). ENERGY STAR® allows computers to consume 15 to 60 watts in sleep mode (depending on power supply size), though many desktop computers available today need only 5 watts or less. ENERGY STAR® depends on users enabling the sleep mode to generate energy savings. Yet recent research by Lawrence Berkeley National Laboratory, Ecos Consulting, and others consistently finds that the sleep mode is disabled on most networked office computers. IT managers and users are disabling it for convenience, or to allow file backups and virus updates at night.
So the good news is that federal consumers are buying computers that use little energy when in standby or sleep mode. The bad news (Figure 3) is that they don't spend much time in that mode. We estimate that federally procured desktop computers are operating about 58 percent of the year and using about 90 to 97 percent of their total annual energy during that time.
Therefore, buying an ENERGY STAR® computer does not ensure that federal purchasers will minimize lifecycle costs, as required by the Federal Acquisition Regulations and Executive Order. The fact is that neither ENERGY STAR® nor FEMP recommendations cover the active mode—that is, the period during which computers are running and use most of their annual energy. ENERGY STAR® recognizes these problems and is moving to address them. It has posted a new draft specification for consideration, but those changes are not likely to take effect in the marketplace until late 2006 or early 2007, after international consultation and a grandfathering period for existing machines are finished.
Act Now to Save Energy and Costs
In order to take advantage now of lower energy use in the active mode, your best bet is to demand 80 Plus-compliant power supplies in all your computer purchases. By acting now and using new model procurement language that addresses active energy use, you can help reduce your agency's energy use and improve the efficiency of computers for all consumers.
For more information, contact the 80 Plus program manager, Geoff Wickes at 503-525-2700 x145 or visit the 80 Plus website.