It's estimated to cost ComEd more than $3 billion to connect data centers to Illinois' electrical grid
Connecting 30 planned or developing data centers to ComEd's northern Illinois grid is projected to cost $3.1 billion through 2031. Consumer advocates warn that insufficient developer deposits could leave households and small businesses responsible for as much as $2 billion, while ComEd says deposits, lines of credit and proposed direct cost allocation will protect ratepayers.
ComEd records filed in an ongoing regulatory proceeding show that transmission and distribution upgrades needed for 30 data center projects in northern Illinois are expected to cost $3.1 billion. Developers have provided $721 million in deposits, while $1.1 billion in transmission costs are backed by 10-year transmission security agreements; some projects are not expected to come online until 2030 or 2031.
The Citizens Utility Board and Environmental Law & Policy Center argue that data center operators should pay the full cost of their grid connections upfront rather than shifting potential shortfalls to households and small businesses. ComEd disputes the advocates' analysis, saying deposits may grow as projects mature and proposing rates that directly assign each data center the costs it creates. Illinois regulators approved ComEd's transmission security agreement requirement in 2025, which has also reduced the number of speculative projects in the utility's queue.