Arizona Data Centers Shift Focus to Water Conservation Amid Public Concerns
In response to growing public concerns over water usage, Arizona’s data center industry is taking significant strides to conserve water in their cooling processes. During a recent Arizona Data Center Alliance event, industry leaders highlighted their efforts to reduce water consumption, while experts from SRP and the Kyl Center for Water Policy provided insights into Arizona’s water management.
Tom Sullivan, COO of Air2O, explained that many data center developers in Arizona are prioritizing water conservation over energy savings when selecting cooling systems. A common strategy is the transition from open-loop to closed-loop cooling systems, which use a recyclable water-glycol mixture to dissipate heat from computer processors. Although this method is approximately 33% more energy-intensive, it significantly decreases water use.
Sullivan noted that a midsize data center using a closed-loop system might consume around 120,000 gallons of water once, compared to over a million gallons daily with an open-loop system. “So the numbers that the media use are true, but they are a true number from the past, and it’s unfair to use a legacy number today, because it’s not the way the data is being used today, the cooling has changed. The water conversation changed,” Sullivan stated.
Despite its efficiency, the closed-loop system may require periodic flushing and refilling due to contamination, which varies by company. A QTS representative suggested this might occur only once every 40 years for their systems. In comparison, Sullivan indicated that a midsize data center’s water use might equate to that of 18 households annually, excluding the water needed for power generation.
Sarah Porter, director of ASU’s Kyl Center for Water Policy, remarked that her team began investigating data center water use two years ago following community concerns. She noted a lack of hyperscale data center development in Arizona and observed that developers are keen to address community worries.
Porter emphasized that Arizona’s water regulation in active management areas (AMAs) has prevented the state from facing water overuse issues seen elsewhere. The Arizona Department of Water Resources oversees these AMAs, which serve a significant portion of the state’s population and industries, requiring state approval and water use reporting for aquifer access.
While industrial cooling remains one of the largest water uses after energy generation, detailed reporting on water consumption for cooling is lacking. Porter asserted, “Utilities still know the total amount of water use, but we don’t know specifically how much of the water that’s being reported for certain types of uses is being used for cooling.”
Porter encouraged residents to urge water providers to ensure industries report detailed water usage data. She also mentioned that power generation within AMAs necessitates water use reporting, with the Palo Verde Nuclear Generating Station being the state’s largest industrial water user.
She highlighted the importance of public awareness in managing water resources effectively, and suggested that interest in water use should extend beyond data centers to encompass other high water use industries.
“People have decided to focus on data centers, and they don’t worry about other high water use industries for the most part,” Porter commented, hoping for fact-based evaluations of data center proposals.
Finally, Porter advised monitoring large industrial developments outside AMAs, as these areas have fewer groundwater pumping regulations.
