Illinois Commerce Commission Approves ComEd's GRIT Project With Four Underground Lines

ComEd received Illinois Commerce Commission approval for its Grid Reliability Infrastructure Transformation project, adding four underground 138kV transmission lines and one new substation in Cook and DuPage counties. The company announced the approval on October 22, 2026, according to Business Wire.

Illinois Commerce Commission Grants ComEd CPCN

ComEd, a unit of Chicago-based Exelon Corporation, serves more than 4 million customers across northern Illinois, or 70 percent of the state's population. The ICC issued a Certificate of Public Convenience and Necessity, which allows a public utility to build major infrastructure after public review of the project's need, design and benefits.

The GRIT project creates a new underground transmission ring connecting three substations, allowing power to flow in multiple directions. If part of the system has a reliability issue, ComEd can reroute power through an alternate pathway, which the company said helps reduce the number and duration of service interruptions.

"The ICC's approval of GRIT provides a clear path to make a critical investment in the transmission system serving one of northern Illinois' most important economic corridors," said ComEd Executive Vice President and COO David Perez. "This project will give our operators greater flexibility to move power through the region, strengthen resilience during extreme weather and other unexpected events, and help ensure reliable service as communities and businesses grow."

Construction begins this fall with grading and drainage for the Dierking substation in the Elk Grove Village area near the Elmhurst Road corridor. Transmission underground work in the other areas begins in January of next year and will be completed in the second quarter of 2029, when the GRIT project will be placed into service. ComEd held two rounds of in-person public open houses in Cook and DuPage counties, plus a virtual open house in 2025, and said feedback helped inform the route selection and its CPCN application.

The underground design reflects the project area's proximity to Chicago O'Hare International Airport, where Federal Aviation Administration height restrictions limit the feasibility of overhead transmission structures. ComEd said the project is needed to serve existing customers and new energy load, including multiple large-load customers that have entered the Wood Dale and Elk Grove Village areas.

Grid Approvals Elsewhere

Ofgem approved £642m to upgrade part of the electricity grid between Suffolk and Essex, including 11 miles of overhead lines and 7 miles of underground cables, Yahoo reported on October 21, 2026. The North Plains Connector Utility Consortium finalized a GRIP award at a Helena forum, with Montana's Department of Commerce receiving about $695 million in federal investment, Business Wire Blog reported on October 22, 2026. FERC approved ISO-NE's process to review utility-planned asset condition transmission projects, with ISO-NE taking the formal advisory role in January, Utility Dive reported on October 19, 2026.

Construction Timeline for GRIT

Transmission underground work in areas beyond the Dierking substation begins in January of next year. ComEd said it will coordinate with local authorities throughout construction and the livening process, with the project placed into service in the second quarter of 2029.