USA, Illinois: Midcontinent Independent System Operator has selected a four-company consortium to develop two major transmission projects across Illinois with a combined estimated value of $1.66 B.
The consortium includes Ameren, GridLiance, Dairyland Power Cooperative and Illinois Municipal Electric Agency. Together, they will build 381 km (237 mi) of new 765-kV transmission lines stretching from the Iowa border to the Indiana state line. The projects are expected to enter service in 2034.
Ownership stakes are divided between the partners, with Ameren Transmission Company of Illinois and GridLiance Heartland each holding 43 %, Dairyland Power Cooperative 11 %, and IMEA 3 %.
The first project, known as STIW, includes two new 765-kV lines running between the Iowa-Illinois border and Woodford County. It is estimated to cost $940 M. The second project, WIIL, will extend eastwards from Woodford County towards Indiana and includes two additional transmission lines and a new 765 / 345-kV substation. Its estimated cost is $718 M.
The new corridor is designed to improve grid reliability, reduce congestion and support growing electricity demand across the Midwest, including demand from data centres, industrial electrification and renewable energy integration.
Both projects form part of MISO’s Long Range Transmission Planning Tranche 2.1 portfolio approved in December 2024.
Source: Energies Media
