WisBusiness: While data centers are touting closed-loop cooling systems that require relatively little water, an environmental law expert with Marquette University says this approach is simply shifting water usage into the power generation sector.
Dave Strifling, an associate professor of law and director of the university’s Water Law & Policy Initiative, spoke yesterday during the Wisconsin Technology Council’s 2026 Wisconsin Tech Summit in Oshkosh.Deploying a newer closed-loop system means a hyperscale data center in the state may go from using up to 5 million gallons of water per day to consuming that amount over a year or longer, Strifling explained. But that reduction is only possible with much more energy being used to power those systems.
“Water use and energy use are intertwined … Power generation also requires a lot of water use, in fact it’s the number one user of water in Wisconsin and probably in the United States as well,” he said. “So this is not a small amount of water that we’re talking about, even though we’ve shifted it to the power generation side of the equation.”Even though this “indirect” water usage by data centers with closed-loop cooling isn’t happening on-site, Strifling raised the question of how to account for that additional water consumption.An executive with WEC Energy Group yesterday said that concern is “a fair position to take” with respect to current generation technologies, such as coal-fired plants and some natural gas facilities that create steam to spin a turbine and create electricity.
But Rich Stasik, the utility’s vice president of state regulatory affairs, argued the natural gas plants the utility is installing now are “more state of the art” and require far less water. For example, its combustion turbine design doesn’t rely on steam, he noted, describing it as “essentially a jet engine” that spins to generate electricity.“So we’re also very mindful of that … Not only in rates of water usage per megawatt-hour generated, it’s going way down projected in the future even with data centers, the absolute amount of water that we expect to use over the next five to 10 years is going to be significantly less than it is today, because of the evolution of the technology,” he said yesterday.
The latest Marquette Law School Poll found in the state, with 70% of respondents saying the costs of these massive projects outweigh the benefits, Strifling noted.“And the number one reason that they gave for having that opinion was water use,” he said. “Not energy use, not rising electrical rates, not the need for additional generation capacity, but water.”Yesterday’s discussion also touched on environmental concerns with another form of data center cooling technology that immerses the entire server structure into liquid to manage temperatures.Nur Bernhardt, vice president of Cloverleaf Infrastructure, noted major companies such as 3M have been developing the technology for this process — but there’s a catch.“The downside or the issue with that is those are highly dependent on forever chemicals … the kinds that never degrade and stay in our water system,” he said yesterday, adding it has its uses but isn’t “a technology that companies are looking at for wide-scale adoption.”
Strifling said most water-related concerns around data centers are more focused on the quantity of usage rather than water quality issues. Still, he added “if you bring PFAS into the mix, some eyebrows will certainly start to go up in terms of what we need to look for in the effluent from those facilities.”