Aurora adopted a data center moratorium. Will other cities follow suit?

Data center construction has surged in industrial hubs around O’Hare International Airport, with Elk Grove Village in particular welcoming major developments.

But in the farthest reaches of the suburbs, data centers have sparked noise complaints from neighbors. Environmental advocates are worried about their consumption of large quantities of electricity and utility capacity.

Such concerns led Aurora’s city council to enact a temporary zoning moratorium on data centers as well as warehouses. Mayor John Laesch made clear officials are not against data centers as a whole.

“It's just trying to give us time to make sure that we have the proper guardrails in place,” he said.

In neighboring Naperville, at least one city council member said he’s exploring the idea of a similar pause.

“I think it makes a lot of sense for us to talk to peer communities, say, ‘What are you doing? What are the standards that we want to hold across the board, really, for Chicagoland?’ And not try to do this in a silo, not try to reinvent a wheel,” City Councilman Ian Holzhauer said.

The Naperville Environment and Sustainability Task Force, or NEST, also has urged the city to adopt a six-month moratorium on the approval or permitting of data centers. A developer, Karis Critical, is seeking to build a data center on the north side of Naperville.

“While Karis has reduced their initial request by half, the new 36-megawatt load is still more than 10% of Naperville's peak demand,” said Ted Bourlard, a member of NEST's leadership team.

Patrick Skarr, a Karis project spokesman, pushed back against the group’s recommendation.

“In Aurora, data centers were being permitted as warehouses, and public hearings were not required,” he said in a statement. “The city had little or no legal authority to deny or even impose conditions on an application. However, Naperville proactively amended its zoning in 2023, giving the city the right to impose conditions on any data center. Naperville does not need a moratorium because it has already acted.”

The concerns

Geneva Mayor Kevin Burns, who chairs the environment and energy committee of the Metropolitan Mayors Caucus, summed up the core debate around data centers during a recent meeting with ComEd officials and a real estate expert.

The facilities house servers that run constantly, and servers must be kept at an optimal temperature and cannot risk interruption in service, he said.

“Therefore, data centers require fail-safe cooling, security and backup, which in turn require enormous amounts of energy and sometimes enormous amounts of water,” Burns said. “Both globally and locally, this need for energy and water stress existing resources and resilience. On the other hand, data centers bring revenue and capacity to communities and the state of Illinois.”

Geneva cannot host a large data center. ComEd would have to upgrade its infrastructure before Geneva could accommodate that type of energy demand, a city spokesperson explained.

While Geneva owns and operates an electric utility, ComEd power lines feed the city’s substations. Geneva interconnects with ComEd to allow the city to receive energy purchased from its regional service transmission provider, PJM.

One megawatt is the power equivalent of roughly 225 single-family homes or two large big-box stores, according to ComEd.

In Aurora, five data center buildings have been built, a city spokesperson confirmed. Another five buildings have been entitled but not yet built or completed. The city also received two applications from a data center developer just prior to the moratorium.

“We find ourselves asking for the necessity of a moratorium so that we have the opportunity to fully research what other communities have done, what the smart moves might be, and then bring them back to council for potential adoption,” said John Curley, chief development services officer.

Several residents spoke out about data center noise last month before the council passed the 180-day moratorium. Generally, the largest noise emitters are diesel emergency power generators and HVAC chiller systems, according to a city presentation.

“We've been suffering for years,” Laura Evans told aldermen.

Aurora’s zoning ordinance and building codes do not include “tailored provisions addressing data center developments,” a city memo notes. The moratorium is designed in part to allow officials to study best practices, review long-term service and infrastructure costs and craft potential zoning standards. It could be extended an additional month if needed.

CyrusOne, one of the data center developers in Aurora, had no comment on the moratorium.

“CyrusOne takes community concerns seriously and has been working collaboratively with the City of Aurora to address noise issues raised by residents,” a company spokesperson said in a statement. “We have completed permanent generator sound walls, temporary rooftop sound walls, and landscaping improvements, and are currently working on permanent chiller sound mitigation solutions.”

The Naperville proposal

Karis Critical is under contract to acquire roughly 40 acres near Naperville and Warrenville roads. The developer originally proposed two data center buildings on the site, but now requests approval of only one.

“Our proposed campus will use less water, generate less traffic, and occupy 65% less space than the 600,000-square-foot office building that previously occupied the property,” Skarr stated.

Karis has pledged to enroll in the city’s green energy certificate program to purchase renewable energy certificates, or RECs, “offsetting 100% of the leasable IT load,” Russ Whitaker, an attorney for the developer, said.

“Naperville’s existing zoning standards have generated an actionable proposal to invest hundreds of millions of dollars into the former Lucent campus, creating a development that reflects strong environmental stewardship while generating jobs and substantial tax revenue,” Skarr added.

The city, meanwhile, has been in contract negotiations with the Illinois Municipal Electric Agency. Holzhauer said the city should not sign any kind of energy contract without having specific provisions that outline how data centers would be serviced.

“Let's start with a foundational question of who's going to supply our energy for this,” he said. “That's not at all clear.”