Ameren Consortium Selected by MISO for $1.23 Billion Iowa Transmission Project

05:55 PM EDT, 10/22/2026 (MT Newswires) -- Ameren (AEE) said late Thursday that its Ameren Transmission Company of Illinois unit, along with NextEra Energy Transmission's GridLiance Heartland and Dairyland Power Cooperative, was selected by the Midcontinent Independent System Operator, or MISO, to build a transmission project in Iowa with an estimated cost of about $1.23 billion. The East Adair - Minnesota/Iowa State Line - Arbor Hill - York Avenue project includes a roughly 187-mile 765-kilovolt line, one 345/765-kV substation and two 345-kV lines totaling about 22 miles, the company said. Ownership will be split 42.5% each for Ameren's unit and GridLiance, and 15% for Dairyland. The 345-kV portion is expected in service by June 1, 2032, and the 765-kV portion by June 1, 2034, subject to regulatory review.