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The Greening of IT
34 How Companies Can Make a Difference for the Environment

Other Ways to Save Energy in the Data Center

As mentioned previously, Gartner Inc. predicts that the cost of sup-
plying energy to a server over its three-year lifetime will soon exceed the
server’s acquisition cost. At a Gartner Data Center Conference in 2008,
these energy-efficient methods were included in a larger list that
included the typical technologies such as virtualization:

■ Consider blade servers: As mentioned previously in this chapter, many
IT vendors (such as HP) have evangelized the virtues of blades and virtu-
alizations. In general, organizations should consolidate servers, storage,
and networks wherever possible. They should replace rack-mounted
servers with blade servers because of shared resources such as power, fans,
networking, and storage. Blades require between 10 percent and 25 per-
cent less power and cooling for the same computing capacity.
Organizations should also consolidate storage by using tiered storage for
different workloads.
■ Use high-efficiency IT equipment power supplies: A lot of manufac- ptg
turers are starting to manufacture equipment that can get better than
80-percent efficiency. IT organizations that improve the energy efficiency
of their power supply units can raise the efficiency of their entire energy
delivery infrastructure. This could lower a data center’s power and cool-
ing needs by 15 percent.
■ Use a high-efficiency Uninterruptible Power Supply (UPS): UPS
efficiency can range from 80 percent to 95 percent. If you were only 80-
percent efficient, maybe with an older UPS system, and you replace that
with a newer UPS system that’s getting 95-percent efficiency, there’s
tremendous gain to be had. You might want to consider replacement if
you run a system that was built in the ‘80s or ‘90s. Efficiency losses in a
data center’s UPS represent about 5 percent to 12 percent of all the
energy consumed in data centers. Manufacturer specifications can differ
widely from measured results because of differences in loading conditions
and test procedures. There might also be differences between efficiencies
measured under reference conditions and under in-use conditions in data
centers. Newer measuring technologies are now being developed to esti-
mate how much energy you can be save by improving UPS efficiency,
developing standardized testing protocols, and proposing efficiency met-
rics for use by the marketplace in comparing units for purchase.