4. Use high-efficiency power supplies.

Power supplies are a prime example of the lack of focus on total cost of ownership in the server market. Inefficient units that ship with many servers today waste more energy than any other component in the data centre, says Koomey, who led an industry effort to develop a server energy management protocol.

Inefficient power supplies can waste nearly half of the power before it gets to the IT equipment. Moreover, every watt of energy wasted by the power supply requires another watt of cooling system power just to remove the resulting waste heat from the data centre.

To make matters worse, server manufacturers have traditionally overspecified power needs, opting for a 600-watt power supply for a server that really should only need 300 watts, says Rich Hetherington, chief architect and distinguished engineer at Sun. "At that level, [the power supply is] at its most inefficient operating point. The loss of conversion is huge. That's one of the biggest sinners in terms of energy waste," he says.

Power supplies are available today that attain 80 percent or higher efficiency even at 20 percent load, but they cost more. Moving to these more energy-efficient power supplies reduces both operating costs and capital costs, however. "If they spent $US20 on [an energy-efficient] power supply, you would save $US100 on the capital cost of cooling and infrastructure equipment," Lovins says. Any power supply that doesn't deliver 80 percent efficiency across a range of low load levels should be considered unacceptable, he says.

5. Break down internal barriers.

Although IT has carefully tracked performance and uptime, most IT organizations aren't held accountable for energy efficiency because the IT function is "stovepiped" from the facilities group. IT generates the load, but facilities gets the power bill, says Brill. Breaking down those barriers is critical to understanding the challenge and providing a financial incentive for change.

The stovepiping problem has also afflicted IT equipment vendors, says Lovins. Engineers are now specialized, often designing components in a vacuum without looking at the overall system — or data centre — in which their components will play a role.

"The design process that used to optimize a whole system for multiple benefits got sliced into pieces, each with one specialist designing one component or optimizing a component for single benefits," Lovins says. "When the integration was lost, we were less able to see how an integrated design could eliminate noticeable losses."

6. Follow the standards. Several initiatives are under way that may help users identify and buy the most energy-efficient IT equipment. A certification program called 80 Plus, which was initiated by US electric utilities, lists power supplies that consistently attain an 80 percent efficiency rating at load levels of 20 percent, 50 percent and 100 percent.

Under a US congressional mandate, the Environmental Protection Agency is working with Lawrence Berkeley National Laboratory to study ways to promote the use of energy-efficient servers. An Energy Star specification could be in place later in 2007.

The US-based nonprofit Standard Performance Evaluation is also working on a performance-per-watt benchmark for servers that should help provide a baseline for energy-efficiency comparisons. The specification is slated for release this year.

7. Advocate for change.

IT equipment manufacturers won't design for energy efficiency unless users demand it. Robert Yale, US principal of technical operations at The Vanguard Group, says his company is involved with The Green Grid and other industry organizations to push for greater energy efficiency.

Joseph Hedgecock, senior vice president and head of platform and data centres at US-based Lehman Brothers, says his company has been lobbying vendors for more efficient server designs. "We're trying to push for more efficient power supplies and ultimately systems themselves," he says.