Data
centers reportedly require more energy than all but five sectors in
the United States, and some estimate that the energy required by
servers and data centers will double by 2011. In fact, the carbon
footprint for data centers may ultimately exceed that of the airline
industry globally. As the public becomes more aware of this usage so
does its concern about it.
Special interest
groups, the media, and others are putting pressure on public and
private data centers to implement energy conservation measures.
Federal and state legislation and programs impose new efficiency
requirements and also provide monetary incentives. This outside
pressure adds to the urgency felt within data center organizations to
reduce energy costs.
Embracing energy
efficiency would seem to be desirable for data centers, but some
facilities managers see energy efficiency like NASCAR racers do. Data
centers are often 24/7 operations, and high-end data centers can be
designed for 99.999 percent availability. Whatever an organization’s
interest in cost savings, actually pursuing energy efficiency might
appear threatening to data-center personnel who are concerned that
complex energy conservation measures (ECM) might diminish
reliability; an outage can be a job-ending event. Yet, these two
goals of reliability and energy efficiency are not necessarily
incompatible and, in fact, can be a “win-win” strategy.
It is key to recognize the energy
characteristics of data centers. In addition to being high energy
users, data centers have relatively flat load curves, as their power
demand tends to remain steady throughout the day. Data centers also
generate substantial heat.
Data center heat is
a significant and growing problem. The heat density of boxes has gone
up, but the temperature tolerance of chips has not changed
appreciably. High-density racks can tax the capacity of ordinary air
conditioning. Duane Morris experienced a situation recently in which
a chiller serving its data center failed, causing an immediate
reduction in network capabilities. Data centers are generally not
efficient users of energy, and some have estimated that data centers
can waste as much as 60 percent of the energy they use to cool
equipment and related systems.
Implementing an
effective energy conservation project can require engineering and
implementation expertise that data center organizations may not
possess. The solutions can include complex strategies such as
installing rectifiers and converting the entire data center to direct
current and eliminating the need for server-by-server rectifiers or
using liquid cooling in racks.
These and
other solutions we discuss are not run of the mill and, for that
reason, may require outsourcing, a time-honored approach to auditing
and determining the best solution to a facility’s energy use. ESCOs
have been auditing buildings and designing, procuring, installing,
and implementing energy conservation measures (ECMs) for decades
through performance contracting. ESCOs employ performance contracts
as a mechanism to overcome the first cost of ECMs and in return to
share in the energy savings to recoup their capital investment. Data
centers are attracting specialized ESCOs which evaluate existing data
center equipment such as racks and UPS systems component by component
and identify hot spots to address cooling issues and reduce costs.
Traditional ESCO strategies include retrofitting HVAC and lighting
systems; more sophisticated data center solutions include ultrasonic
dehumidification, blanking panels, and improved under-floor airflow.
The widespread adoption of energy-efficiency best practices like
these by data centers could potentially save one million kilowatt
hours annually in the US.
Since ESCOs play a
significant role in determining the scope of their own services by
performing auditing, designs, procurement, and installation, data
center owners must understand the ESCO’s energy services agreement
and make certain it reserves “go or no go” decision-making rights
for the owner at a key points. The owner should understand precisely
how any guarantee will be determined and what contractual obligations
the owner will have. Owners may mistakenly assume that the ESCO will
handle every aspect of a project and omit tasks that are necessary if
the project is to achieve all its goals.
It is
also important for the data center to differentiate between active
ECMs such as cooling systems and passive measures such as the
retrofitting of energy-efficient lighting. Active systems will
require the same degree of reliability as the data center itself.
Although a data center will generally seek a cooling system that it
can operate with its own personnel, it may be desirable to arrange
for supplemental outside monitoring to provide warnings and make
on-line repairs if possible. It may be necessary to have a separate
monitoring agreement for this purpose, and it is important to
understand how the monitoring process will be conducted under that
agreement and, again what requirements will be placed upon the
owner.
Data centers need highly responsive
emergency and maintenance services. Contracts for such services can
include built-in response-time leeway, which the owner must
understand. Also, the remedies are likely to be basic. No maintenance
and emergency services provider can be expected to provide a
contractual remedy for consequential monetary losses due to partial
or complete system failures due to cooling
failures.
Similarly, an energy services
agreement with an ESCO might protect against additional energy costs
or the replacement of failed ECMs, but it would be unusual to see
business losses covered in such an agreement. In fact, nearly all
energy services agreements specifically disclaim consequential or
indirect loses, and some put monetary caps on any damages that an
owner such as a data center may sustain. Similarly, warranties on
equipment are generally limited to manufacturers’ warranties of
parts and labor.
Although, it may be difficult
to secure contractual protection, the author believes that a data
center is unlikely to experience increased risk of system failure
from new energy-efficient equipment as compared to its existing
cooling and lighting equipment. In fact, the newer equipment may be
more reliable than the existing equipment, and, in light of the
potential financial and environmental benefits to be gained from the
implementation of ECMs in data centers, the benefits should more than
justify any potential risks.