Water is an especially difficult subject in Arizona because the answers are rarely simple. The answer depends on the cooling technology, location, water source, climate, facility design and operating approach. A newer closed-loop design can look very different from an older facility that relies heavily on evaporative cooling.

The day opened with an overview of open- and closed-loop cooling systems led by Tom Sullivan of Air2O. Sullivan emphasized that the first challenge is simply getting everyone to use the same language and compare the same things. He returned to the need to “anchor our conversation around common metrics.”

“The cooling has changed, the water conversation has changed.”

Tom Sullivan of Air2O

Even the language creates confusion. Water withdrawal is not the same as water consumption, and direct water use at a facility is different from indirect water associated with electricity generation. Two projects can be described accurately and still sound nothing alike if each is using a different measure. Older water-use figures may be accurate for the technologies they describe while still being a poor comparison for a newer facility.

Molly Castelazo, CEO and Content Strategist at Castelazo Content, challenged the industry to recognize that distinction. Some of the high water-use figures communities have heard were real for earlier generations of data centers and evaporative cooling systems. What people have heard, she said, can represent “a legitimate concern and a legitimate question.”

The credible response explains what was true, what has changed, and what applies to the project in front of the community today. Telling people they were wrong for asking is not an answer.