MISO Achieves Major Milestone with New Power Grid Projects in Illinois

MISO's Strategic Initiative to Bolster the Illinois Power Grid

In an ambitious move aimed at enhancing the reliability and efficiency of the power grid in Illinois, the Midcontinent Independent System Operator (MISO) has made a significant announcement: the selection of a consortium comprising Ameren Transmission Company of Illinois (ATXI), GridLiance Heartland, Dairyland Power Cooperative, and the Illinois Municipal Electric Agency (IMEA). This collaboration will focus on the development and maintenance of two major transmission projects, a critical step in strengthening the energy infrastructure needed to support growing communities in the Midwest.

Overview of the Projects

The projects, known as the Sub T – Iowa/Illinois State Line – Woodford County (STIW) and Woodford County – Illinois/Indiana State Line (WIIL), are designed to create a robust 765-kilovolt (kV) backbone. This upgrade aims to deliver safe, reliable, and competitively priced energy for decades to come. The STIW project features the construction of two 765-kV transmission lines, approximately 149 miles in length, connecting the Woodford County Substation with the Iowa/Illinois state line and extending into Iowa. This initiative is projected to cost around $940 million.

Conversely, the WIIL project will construct two additional 765-kV transmission lines covering a total of 88 miles, along with a new 765/345-kV substation. One of these lines will extend from the Woodford County Substation in central Illinois to the Illinois/Indiana state line, while the other will interconnect with an existing line segment. The WIIL project is estimated at $718 million. Ownership stakes in these projects will be split among the consortium members, with ATXI and GridLiance each holding 43%, Dairyland at 11%, and IMEA at 3%.

Importance of these Projects

The projects are vital for constructing a more resilient transmission backbone in the Midwest, which will not only improve reliability but also accommodate the growing energy demands of the region. As Shawn Schukar, chairman and president of ATXI, stated, “We are committed to delivering infrastructure that strengthens the grid and creates value for customers both now and over the long term.”

In a similar vein, Matt Valle, president of NextEra Energy Transmission, emphasized the importance of these initiatives in enhancing energy infrastructure: “These projects are critical to building a stronger, more resilient transmission backbone for the Midwest.” This sentiment was echoed by Dairyland’s executive vice president, Ben Porath, who highlighted the consortium's role in ensuring a flexible and reliable transmission system for future generations.

Doug Brown, CEO and President of IMEA, added that increasing transmission capacity is crucial for fostering long-term economic development and integrating new resources into the grid.

Future Outlook

Both the WIIL and STIW projects are part of MISO's Long Range Transmission Planning Tranche 2.1 Portfolio, which received initial approval in December 2024. With an expected in-service date of 2034, following extensive regulatory review and community engagement, these projects mark a transforming moment for Illinois' energy landscape. This strategic initiative underscores MISO's commitment to strengthening the regional power grid, benefitting both current residents and future generations.

About the Consortium Members

Ameren Corporation

Headquartered in St. Louis, Ameren Corporation is a principal energy provider for over 2.5 million electric customers and more than 900,000 natural gas customers across a 64,000-square-mile area, with services offered through its Ameren Missouri and Ameren Illinois utility subsidiaries.

NextEra Energy Transmission

As North America's leading competitive transmission company, NextEra Energy Transmission operates over 3,200 miles of transmission lines in 19 states and Canada, focusing on modernizing and strengthening the electric grid to meet the increasing energy demands.

Dairyland Power Cooperative

Based in La Crosse, Wisconsin, Dairyland provides wholesale electrical requirements for 24 distribution cooperatives, supplying power to over 800,000 individuals across four states.

Illinois Municipal Electric Agency (IMEA)

IMEA is a not-for-profit unit of local government created to provide affordable, reliable electricity to municipal electric systems throughout Illinois. Comprised of 32 municipal systems, IMEA supports local communities in securing sustainable energy solutions while preserving local oversight.

The collaboration of these entities aims to pave the way for innovative energy solutions that address rising demands and enhance reliability in Illinois's power sector.