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64 64 P a r t I I : a r t I I : C C o n s u m p t i o n I s s u e so n s u m p t i o n I s s u e s

A 100-watt (W) bulb uses 100 watt-hours of electricity in 60 minutes. As such, ten 100 W
light bulbs will use a total of 1 kWh of electricity per hour. But electrical power costs are
different around the country.
For instance, the U.S. Department of Energy reports that in New York in 2007, 1 kWh
costs 15.48 cents for commercial use. In Minnesota, the same amount of commercial power
costs 7.47 cents. To power those ten light bulbs in New York, 10 hours a day, 5 days a week,
52 weeks a year (10 × 5 × 52) would cost US$402.48. In Minnesota, those same ten light bulbs
would cost US$194.22—U.S. Department of Energy, 2007. We’re not trying to build a case to
convince you to relocate your business to Minnesota (but if you do, let the Governor know
we swayed you), but rather to illustrate a point—electricity costs different amounts in
different places.
Table 4-1 compares the average price per kWh for each region of the U.S. and shows
how much it has increased in one year.

NOTE You can see the average for each U.S. state at the Department of Energy website via Link 4-1.

Because most companies aren’t just running on ten light bulbs, let’s put the numbers in
realistic terms. International Data Corp. estimated that companies worldwide spent about
$29 billion to cool datacenters in 2007, up 400 percent from 2000—IDC, 2006.

Causes of Cost
Cooling is a major component of your power consumption and, by extension, your IT budget.
A number of issues drive up power consumption and cooling costs, including the following:
• Increased power consumption as more servers and storage devices are deployed.
• Increased heat density in the racks because of increased computing power in a
confined space.

Commercial Power Cost Commercial Power Cost
Region in 2007 (Cents per kWh) in 2006 (Cents per kWh)
New England 14.79 14.66
Middle Atlantic 13.2 12.81
East North Central 8.62 8.18
West North Central 6.86 6.75
South Atlantic 8.63 8.42
East South Central 7.97 7.97
West South Central 9.37 9.33
Mountain 7.73 7.61
Pacific Contiguous 11.27 11.36
Pacific Noncontiguous 16.94 17.35
TABLE 4-1 Price Per kWh Varies Around The Nation and Is Increasing