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C h a p t e r 1 : h a p t e r 1 :
C O v e r v i e w a n d I s s u e s v e r v i e w a n d I s s u e s 17 17

NOTE That doesn’t even take into consideration the pollutants generated during mining and
transportation.

But that’s just for one rack switch. Multiply those numbers (1,780 pounds of coal and PART I
two tons of carbon dioxide) by the millions of switches in the world, and you can see that
PART I
PART I
we have a big problem on our hands.
Consumption
The EPA estimated that datacenters consume 1.5 percent of the nation’s electrical power, as
shown next—US EPA, 2007. That’s barely enough to even show up on a pie chart, but it still
equates to about 61 billion kWh per year. That’s twice as much power as was consumed five
years ago, and that number will double again by 2011 to more than 100 billion kWh.

IT consumption
All other US power consumption

Unless CIOs do something to change that trend, 100 billion kWh will require the equivalent
of 15 new power plants to be constructed. It would churn out as much as 47 million metric
tons of carbon dioxide per year.

NOTE That’s not exactly true. We wouldn’t have to build that many power plants—they can’t be
built that quickly anyway. Instead of building all those power plants, we could just have
brownouts and rolling blackouts during peak usage times.

The EPA has suggested a number of ways in which datacenters can be more energy
efficient, ranging from properly organizing physical space to reduce cooling loads to using
energy-efficient power supplies.
Higher energy-efficient power supplies can lower your datacenter’s electrical bill
dramatically. Annual savings of US$2700 to US$6500 per rack are possible simply by moving
to energy-efficient power supplies.
The ideal power supplies are at least 80 percent efficient. Supplies reaching that level of
efficiency are certified as 80 Plus. To get an idea of what you can save by using an 80 Plus
certified power supply, go to www.80plus.org/80sav.htm. There, you’ll see a calculator like
the one in Figure 1-4.
The calculator allows you to enter the number of 80 Plus certified computers and servers
your organization is using, and then it allows you to put in the average price for electricity
(expressed in kWh). A link to the calculator can be found at www.greenitinfo.com/links listed
as Link 1-2.