Google Proposal To Increase PC Energy Efficiency

From the NY Times:

... The Google plan calls for a shift from multivoltage power supplies to a single 12-volt standard. Although voltage conversion would still take place on the PC motherboard, the simpler design of the new power supply would make it easier to achieve higher overall efficiencies.

The Google proposal is similar in its intent to an existing effort by the electric utility industry to offer computer makers financial incentives for designing more efficient power supplies for personal computers. Existing PC power supplies vary widely in efficiency, from as high as 90 percent to as low as 20 percent.

The existing effort, 80 Plus, sets an 80 percent efficiency standard as a goal. It is a partnership between Ecos Consulting, an environmental consulting firm, and a group of electric utility companies. Ecos began measuring the efficiency of computer power supplies in 2003 and found that none of them met the efficiency standard.

But a technical adviser for the utility project said in a telephone interview on Monday that since the program began last year, the industry has begun to move toward more efficient designs.

“We now have 70 compliant designs from 15 to 20 manufacturers,” said the adviser, Chris Calwell, vice president and director for policy and research at Ecos Consulting. The new designs are just becoming available in commercial products, he said.

Modern PC designs shift the control of voltage to the motherboards, making the multiple voltage requirements of industry standard power supplies unnecessary, wrote Urs Hölzle and William Weihl, the authors of the Google paper, “High-Efficiency Power Supplies for Home Computers and Servers.”

... The overall Google goal is to be applauded, Mr. Calwell said, but by redesigning and simplifying power supply design, he worries that it is possible that overall efficiency may not be improved significantly.

Both the Google engineers and Mr. Calwell agreed that there was a significant design flaw, which they described as “overprovisioning,” in today’s PC power supplies. “It’s like putting a 400-horsepower engine in every car, just because some cars have to tow large trailers every once in a while,” Mr. Calwell said.

The Google white paper argues that the opportunity for power savings is immense — by deploying the new power supplies in 100 million desktop PC’s running eight hours a day, it will be possible to save 40 billion kilowatt-hours over three years, or more than $5 billion at California’s energy rates.

Although Google does not plan to enter the personal computer market, the company is a large purchaser of microprocessors and has evolved a highly energy-efficient power supply system for its data centers.