Karis Scaled-Back Naperville Data Center Heads to Council

After months of heated debate, a controversial data center proposal is heading for a vote before the Naperville City Council Tuesday night, setting up a high-stakes test of how far the Chicago suburb is willing to go to accommodate energy-hungry infrastructure near residential neighborhoods.

The developer — Naples, Florida-based Karis Critical — pared back its original plan, which once called for two data centers near Naperville and Warrenville roads. The Daily Herald reported that the current request seeks approval for a single facility, a move the company said reflects an effort to “right-size” the project for the city, according to statements made to council members and city documents. For nearby residents, the changes haven’t gone far enough.

The council will consider a draft development agreement that lays out strict conditions governing construction, operations and ongoing oversight. Under the proposal, the data center would be required to buy all of its electricity from the city, with peak demand capped at 36 megawatts. Karis would also be on the hook for any infrastructure upgrades and would guarantee that the added load doesn’t drive up electric costs for other Naperville customers.

City staff said enough electrical capacity exists to support the project while accommodating reasonable growth through 2030, based on analysis conducted with consultants and ComEd, the primarily electrical supplier for Chicago and Northern Illinois. Still, a staff report cautions that absorbing another large-load customer in the I-88 corridor could require significant system upgrades, effectively limiting future options unless more power is secured.

That concern is fueling resident opposition, along with fears about noise and air quality. At a recent meeting, neighbors pointed to diesel backup generators — up to 24 of them — as a particular flashpoint. The agreement would limit testing to weekdays, cap it at 10 hours annually and restrict non-emergency use during poor air quality days. Only two generators could be tested at once. Critics argue those safeguards don’t address the long-term reality of 24/7 industrial operations near homes, some just hundreds of feet away.

Noise from cooling systems is another worry, prompting calls for the city to modernize its noise ordinance and set clearer buffers between data centers and residential areas. Opponents said other municipalities have already tightened zoning rules after learning about the impacts of allowing data centers near neighborhoods.

The fight also taps into broader questions about land use along Naperville’s I-88/Diehl Road corridor. A city-commissioned study urged officials to pursue higher-value, mixed-use and life sciences development that supports a more vibrant “live-work-play” environment. Residents and some council members are questioning whether a massive, power-intensive facility forecloses those possibilities.

Karis, which pledged at least $250 million in investment excluding tenant equipment, argued the site’s proximity to the Indian Hill substation makes it uniquely suited for a data center and positions Naperville for long-term tax revenue and tech-sector jobs.

Naperville isn’t the only Chicago suburb where Karis is eyeing data center development. Anthony Iatarola’s firm, 5a7, and its affiliates sold more than 180 undeveloped acres in Hoffman Estates for $45 million to a Karis venture in February, which is prepping the land for a data center operator.

— Eric Weilbacher