Wisconsin Southeast Transmission Project

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Strengthening Wisconsin Transmission

The Wisconsin Southeast Transmission Project (WISE) is a new 345 kV, 106-mile transmission project that will help meet growing electricity demand, support new energy sources, and strengthen the region’s electric grid. 

Viridon was selected as part of the Midcontinent Independent System Operator (MISO)’s $22 billion Long-Range Transmission Plan (Tranche 2.1), approved in December 2024, which supports long-term electric grid reliability and growth across the Midwest. 

Project at a Glance

345 kV
high-voltage transmission system
106
miles with 1 substation
4
transmission line segments
2033
target in-service date

Building a Stronger Grid

A modern transmission system is essential to deliver reliable electricity where and when it's needed. 

Modernizes and replaces aging transmission infrastructure

Supports growing electricity demand

Strengthens Wisconsin's transmission backbone

Improves the grid's ability to respond to outages and changing energy needs

Why Now?

 Electricity demand is climbing at a pace not seen in decades, according to MISO's 2026 Reliability Imperative Report, driven by economic growth, new manufacturing facilities, increased electrification, and the need to upgrade aging infrastructure. Selected through MISO’s competitive transmission bidding process, the WISE project will help the electric system keep pace with this growing demand, delivering reliable and affordable power while supporting a more resilient and sustainable energy future.  

Project Benefits

Support Local Communities

The project is expected to create 197 jobs and generate $271 million in total economic impact.

Meet Growing Demand

Supports growing electricity needs by helping ensure reliable power is available for homes, businesses, and communities – even during periods of peak demand.

Improve Grid Reliability

Strengthens the grid with additional capacity and multiple transmission pathways, reducing outage risk and improving system resilience.

Expand Regional Energy Access

Connects Wisconsin to a diverse mix of regional generation resources. The transmission system can deliver electricity from any energy source based on system needs.

Deliver Customer Value

Selected through a competitive process as the lowest-cost solution, helping deliver long-term value for electric customers.

About the Project

Project Location

WISE includes one substation and four transmission line segments across seven counties in southeast Wisconsin.

  • Big Bend Substation (Waukesha County) 

  • South Fond du Lac – Jefferson (Fond du Lac, Dodge, Jefferson Counties)  

  • Fort Atkinson – Whitewater (Jefferson, Walworth, Rock Counties)  

  • REC Bradford – Sugar Creek (Rock, Walworth)  

  • Big Bend – Sugar Creek  (Racine, Walworth, Waukesha Counties) 

Project Timeline

  • 2024 – Selected through MISO’s Long-Range Transmission Planning process (Tranche 2.1)
  • 2026 – Community engagement and environmental review
  • 2027 – Certificate of Public Convenience and Necessity filing
  • 2030 – Construction begins (projected)
  • 2033 – Target in-service date
 
About Viridon 
Viridon develops transmission projects that strengthen the electric grid across the Midcontinent Independent System Operator (MISO) region. Built on a strong utility foundation, Viridon Wisconsin combines customer focus, innovation, cost discipline, and speed to deliver critical infrastructure projects.
 
About National Grid Ventures 
National Grid Ventures (NGV), the commercial arm of National Grid plc, develops, builds, and operates energy infrastructure that strengthens power systems and delivers reliable, affordable energy. Its portfolio includes competitive transmission, battery storage, solar, LNG storage, conventional generation, and one of the world's largest portfolios of high-voltage subsea interconnectors. NGV brings decades of experience building energy infrastructure that supports economic growth, improves reliability, and helps deliver lower‑cost energy to customers.