The Cost of Water
in the Data Center
As Coleridge made clear, water is essential for survival. In
California for example, people are finding new meaning in the
phrase, “water, water everywhere and not a drop to drink”. Since
data centers hadn’t been invented when he published The Rime
of the Ancient Mariner in 1798, he didn’t mention them. But
if they had, he certainly would have included them in his epic
poem since water is too often a common requirement for their
operation. This water dependency is an area of consideration
that businesses should factor into their plans for upcoming data
centers.
A high percentage of today’s data centers use water-based
cooling methods to keep them from becoming the equivalent
of a Hopi sweatbox in the desert. Although evaporative cooling,
whether through traditional towers or “advanced” adiabatic
cooling systems (aka swamp coolers), remain highly effective
cooling methods, when you’re planning a new data center you
may want to consider the impact of the weather and water
availability on your decision.
An article in USA Today entitled “Drought Condition Spreads Over USA” confirmed what many of us have
probably already surmised, water is currently at a premium. In fact, according to the U.S. Drought Monitor,
61% of the 48 contiguous states are in “abnormally dry” or drought conditions. The six major data center
markets (NY/NJ, N. Virginia, Chicago, Dallas, San Francisco and Phoenix) all fall within these areas. So what
can this mean for a new data center? Depending on the severity of the drought conditions, planning approvals
for sites seeking to use water-based methods could be delayed, returned for modification or, in the worst
case, turned down. The other potential ramification is water use restrictions that escalate water rates. For
systems that use millions of gallons of water per year this can definitely have a detrimental effect on your
operational budget.
To better realize why the availability of water is so critical for many data centers, it’s important to understand
just how much H2O the average water-based cooling data center actually uses. According to James Hamilton
of Amazon, the average 1MW data center uses 17 million gallons of water annually, and usage only increases
with size as a 15MW facility is estimated to use approximately 131 million gallons annually. No matter how
you look at it, that’s a lot of water. In many instances, this seemingly insatiable desire for water is exacerbated
by the qualifications for what is available. Since most facilities contract for water with their local facilities,
they can receive only the treated version used by the rest of the community. This naturally adds cost to their
overall water budget. Although “gray” (untreated) water is usable for most data centers (with a lot of expense
and operations complexity at the data center to condition the water), it isn’t always available for use. A recent
article in the New York Times demonstrated how Los Angeles is illustrative of this problem due to the fact
that a recycled water pipeline could take years to reach most of the area’s data center sites.
2
Due to the prevalence of these conditions across the country, new data center shoppers would be wise to
consider addressing issues of water availability and scarcity driven price increases by both increasing the
operating temperatures within their facilities and adopting air-side economization as their preferred cooling
method.
Historically, the temperatures maintained within a data center have resembled those of the average meat
locker. Despite popular misconception, this has not been a data center requirement for quite some time.
Since 2004, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)
TC9.9 committee has been expanding its allowable and recommended temperature ranges. From a practical
perspective, this means cooling requirements for facilities that adopt these expanded operating conditions are
reduced thereby expanding the ability of data center operators to use non-water based cooling methodologies
i.e., air side economization.
ASHRAE TC 9.9 Guidelines
have expanded the range
of acceptable operating
temperatures.
As the name implies, airside economization uses the air outside of the facility to cool it. “Free Air” (specifically
defined by ASHRAE as a temperature between 59°F and 81°F) is drawn into the facility through finely
calibrated filters (to remove particulates) and used to cool the facility. While certain areas of the country
have more “Free Cooling” hours than others, the technology isn’t just a geographic phenomenon. In fact,
there is virtually nowhere in the country that it can’t be used. Even Houston provides over 3600 hours of
“free cooling” annually1. Thus, even in the most drought stricken areas of the country, outside air provides an
alternative that is less expensive and is not subject to fluctuations in resource availability than water-based
alternatives.
1
Allowable range is NOT the recommended range. It is important to understand the full implications of ASHRAE TC9.9 recommendations
as it relates to your risk tolerance.
3
Even in the country’s most
southern locations airside
economization is a viable
cooling alternative.
Drought, and associated water restrictions can also have a substantial impact on your data center’s power.
For example, Quincy, Washington has become a destination point for new data center construction to take
advantage of its inexpensive hydroelectric power. Quincy is located in Eastern Washington, an area that is
largely desert-like and relies exclusively on the power produced by the Wanapum and Priest Rapids dams.
What would happen if this area fell into a period of pro-longed and severe drought?
We actually have a pretty good idea of what would happen since the area experienced a severe drought in
2001 and a slightly lesser one in 2005. In both instances, water restrictions forced the lay-offs of thousands
of nearby aluminum factory workers, as the water available wasn’t enough to generate the power to run the
factories’ smelters. In both cases, electrical prices also rose substantially as power had to be imported from
California. These are important considerations since 100-year projections for Eastern Washington indicate
the area will experience extreme or severe drought 10-15% of the time, and Quincy resides in one of the
nine (9) counties designated by the state’s Hazard Mitigation Plan as “most vulnerable to drought”. The
purpose of this illustration is to demonstrate that water availability can fluctuate over time, a phenomenon
that can have severe consequences. Since airside based facilities are not subject to these potential swings in
availability, data center end users have a broader array of geographic locations to choose from when selecting
future site locations.
How the use of water for either cooling or power, or both, in your data center is a consideration that should
be given careful evaluation in businesses’ planning processes. The impact of severe weather conditions can
have a dramatic impact on operations and costs. Businesses should be sure that they carefully evaluate all
their alternatives before committing to a site for their next data center since the last hundredth of a percent
of PUE doesn’t matter that much if you can’t operate your facility.
4
Led by a management team that has built and operated billions of dollars in data centers all over the world, Compass provides an alternative for customers
contemplating taking on the complex task of building their own data centers or having to settle for multi-tenant colocation. Compass builds dedicated facilities that
put you in complete control of every aspect of your mission critical data center including your network and security system, the ability to use your own operational
and security personnel and even the option to lease or purchase the site. Easily expandable based on your growth and budget requirements, each Compass data
center has been designed to serve as a long term strategic asset through capabilities like simultaneous high (up to 30kW per rack) and low density support and
features our Workflow Optimized™ design to enhance the efficiency of your regular operations. Your data center can also be located anywhere you need it and is
delivered in less than six (6) months from initial ground breaking on a pad ready site.
© Compass Datacenters 2015