Illinois City Approves $20B AI Data Center After Marathon Public Hearing

The Joliet City Council on Thursday approved a proposed $20 billion AI data center campus that would become the largest in Illinois, concluding weeks of debate marked by lengthy public opposition and a delayed vote earlier in the week.

The council voted 8-1 to approve an annexation agreement for the 795-acre “Joliet Technology Center,” a project led by developer PowerHouse Data Centers and its parent Hillwood, clearing a key hurdle for construction to begin as early as 2027.

The decision followed a marathon public hearing on Monday that stretched more than six hours, forcing officials to postpone the vote after dozens of residents voiced concerns over the project’s environmental impact, energy use and proximity to homes. The meeting extended past midnight and was ultimately recessed due to state rules prohibiting public meetings on election days.

When the council reconvened Thursday evening, City Hall was again filled with hundreds of attendees, including union construction workers supporting the project and residents opposing it.

The development, planned near Rowell and Bernhard roads southwest of Chicago, would consist of 24 two-story data center buildings spanning roughly 6.9 million square feet. Built in four phases through 2032, the campus is expected to reach up to 1.8 gigawatts of power demand.

City officials and developers emphasized the project’s economic benefits, including an estimated $2.1 billion in tax revenue for local governments over 30 years, alongside $310 million in property taxes and tens of millions more in utility-related revenues. The project is also expected to generate between 7,000 and 10,000 construction jobs and about 700 permanent positions once fully operational.

Mayor Terry D’Arcy highlighted the anticipated funding boost for local schools, while City Manager Beth Beatty said the agreement “sets clear expectations for infrastructure, services, and community benefits” tied to the development.

Supporters argued that the project positions Joliet to capture growing demand for data center capacity driven by artificial intelligence and cloud computing, noting that similar facilities are being built across the country.

Opposition, however, remained vocal. Residents raised concerns about rising electricity costs, water usage, noise and long-term environmental effects. Some questioned how power would be allocated during potential grid shortages, while others worried about the impact on nearby property values and farmland.

Experts testifying on behalf of the developers said the project had been reviewed by regional grid operator PJM Interconnection and did not raise concerns about power availability, though skeptics remained unconvinced.

The approval follows earlier backing from the Joliet Planning Commission this month and marks a significant step forward for the project, which was first proposed in October 2025 but faced delays amid growing public scrutiny.

With the council’s vote secured, developers are expected to move into the planning phase ahead of a targeted construction start in early 2027, setting the stage for one of the largest data center buildouts in the U.S. Midwest.