31 Jan 2024

Residents and businesses in seven southwestern Illinois counties are benefiting from more reliable energy thanks to the upgrade of a 140-mile 345-kV transmission line from Cahokia to Joppa.

The recently completed, multiyear Southern Illinois Reliability Project is improving system reliability while also opening pathways for clean energy to be distributed to the region and increasing transmission capacity to meet the area’s growth needs.

Southern Illinois Reliability Project

This project will help control energy costs and improve reliability thanks to smart grid technology"

"We begin and end each project with our customers in mind," said Shawn Schukar, Chairman and President, Ameren Transmission Company, adding "This project will help control energy costs and improve reliability thanks to smart grid technology. It also represents another successful partnership with local union contractors – this project was built for Illinois residents by Illinois residents."

The Southern Illinois Reliability Project reconstructed the existing 230-kV transmission line originally built in the 1950s. Customers in St. Clair, Washington, Perry, Franklin, Williamson, Johnson, and Massac counties are now benefiting from the infrastructure upgrades.

Energy grid for future generations

"This transmission project represents a huge value-add for our customers by increasing energy supply capacity, improving reliability and giving us the ability to bring cleaner energy sources to local homes and businesses," said Ellen Prinster, Manager, Ameren Transmission project management, adding "We are transforming the energy grid for future generations while investing in the communities we serve."

Crews rebuilt the transmission line in seven phases along the existing corridor. The project included upgrades at 13 existing substations and the construction of four new substations along the 140 miles of transmission line.

Innovative engineering solutions

As an employer with deep roots in this region, we’re proud to partner with Ameren to build the reliable energy infrastructure that our neighbors and families count on every day,” said Trey Wiegmann, Vice President of Construction Services, Poettker Industrial, adding “This project underscores the role that local contractors play in getting transmission projects completed on time and using local labor.”

The large scope of work required innovative engineering solutions and meticulous coordination with suppliers during the COVID-19 pandemic. Challenging conditions along the construction corridor, including rocky terrain and tight rights-of-way, resulted in the development of new, steel H-frame structures to support the 345-kV transmission line.