CHICAGO (January 21, 2026)—Data centers are coming to Illinois, requiring massive amounts of electricity at a time when household bills are already on the rise. A new report released today by the Union of Concerned Scientists (UCS) highlights the effects of data centers’ growing electricity demand on Illinois’ power grid and how decisionmakers can mitigate harmful impacts on people and businesses by driving more clean energy development and adopting stronger ratepayer protections in the state.
The report, “Data Center Power Play,” assesses the potential costs of meeting data center load growth over the next 25 years and the consequences for climate, health and the state’s dependence on electricity imports. Since future data center demand growth is highly uncertain, largely due to a lack of transparency from utilities and Big Tech companies, UCS modeled multiple demand growth scenarios as well as energy policy scenarios for how that demand is met.
A state-specific fact sheet shows that in Illinois, data centers will account for up to 64% of electricity demand growth by 2030 in the UCS mid-level data center demand growth scenario. Without better ratepayer protections, over the next 25 years such data center growth could put Illinoisians at financial risk of $24 billion in electricity systems costs, UCS reports. Absent stronger policies, data center load growth will also lead to worsening pollution from Illinois’ fossil fuel power plants and rapidly escalate the state’s reliance on out-of-state electricity.
Conversely, the UCS analysis shows that by adopting more robust state and federal clean energy policies to meet this demand, Illinois would see the economic benefits of more clean energy development and deliver up to $2.8 billion in health savings and avoid $112 billion in global climate damages between now and 2050.
“As the AI boom is already reshaping the energy landscape, modernized polices specific to data centers are urgently needed to protect Illinois’ clean energy future and its electricity ratepayers,” said James Gignac, report author and Midwest policy director for the Climate and Energy Program at UCS. “Without taking steps like requiring data centers to pay for building new renewable energy sources rather than gas plants, their electricity demand will increase pollution and dramatically escalate Illinois’ reliance on imported power from other states. Common-sense measures to protect ratepayers and grow clean energy in Illinois is the path we need.”
You can read about national-level findings here and related blog posts here. UCS also released state fact sheets for Michigan and Wisconsin alongside the national report.