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

from 2000 to 2006, the largest increase among different types of servers. The
power and cooling infrastructure that supports IT equipment in data centers
also uses significant energy, accounting for 50 percent of the total consump-
tion of data centers. Among the different types of data centers, more than
one-third (38 percent) of electricity use is attributable to the nation’s largest
(that is, enterprise-class) and most rapidly growing data centers.

EPA Incentives and Voluntary Programs to Promote
Energy Efficiency

To realize the potential benefits from greater energy efficiency in the
nation’s data centers, a number of market barriers need to be addressed. The
adoption of energy-efficient technologies and practices is often impeded by
barriers such as higher first cost, lack of knowledge, institutional failures,
and perverse incentives, and these issues apply equally to data centers. The
barriers that prevent data centers from adopting changes that offer reasonable
paybacks are typically not technological but organizational. Three barriers of
particular importance for data centers follow:
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■ Lack of efficiency definitions: It is difficult to define energy efficiency
for a complex system such as a data center or a server. Energy efficient is
usually defined based on the delivery of the same or better service output
with less energy input, but for servers and data centers, service output is
difficult to measure and varies among applications. Data center operators
need standard definitions of productivity to purchase energy-efficient
equipment, operate it in an optimal way, and design and operate the
buildings to house it.
■ Split incentives: In many data centers, those responsible for purchasing
and operating the IT equipment are not the same people who are respon-
sible for the power and cooling infrastructure, who, in turn, typically pay
the utility bills. This leads to a split incentive, in which those who con-
trol the energy use of the IT equipment (and, therefore, the data center)
have little incentive to do so.
■ Risk aversion: With the increasing importance of digital information,
data centers are critical to businesses and government operations. Thus,
data center operators are particularly averse to making changes that
might increase the risk of down time. Energy efficiency is perceived as a
change that, although attractive in principle, is of uncertain value and,
therefore, might not be worth the risk.