2 myths about closed loop cooling in data centers

Our Take

Credit to the Milwaukee Journal Sentinel and reporter Bill Schulz for getting this on tape. Data center developers love to lead with "closed loop cooling" as their trump card in community meetings — it sounds like a system that sips water once and never asks for more. Melissa K. Scanlan, who directs water policy work at UWM's School of Freshwater Sciences, used her time at the paper's Turner Hall town hall to push back on that framing, and that's exactly the kind of scrutiny these deals need before ground gets broken, not after.

Here's why it matters beyond one Wisconsin town hall: closed loop systems still require water to fill the loop initially, still lose water to evaporation and leaks over time, and still get sited near rivers and aquifers that utilities and residents rely on for everything else. When a company says "closed loop" in a permit hearing or a economic development pitch, it's doing a lot of rhetorical work — and most zoning boards and city councils aren't hydrologists. They're taking the pitch at face value, then signing off on tax abatements and land deals based on it.

That's the pattern we track at GridWatch — the gap between the marketing language in a groundbreaking press release and the actual resource draw once the servers are humming. Check our facility map to see what's been proposed or built near you, and if your town is about to take a developer's word for it on water, head to our take-action page for questions worth asking before the vote.