bell-regular Please Note: The WISE 345kV Transmission Line Project is in the early stages of routing and siting of the Project. In the coming months, we will be engaging with community leaders, landowners, and other key stakeholders to assist in this process. Once initial routes have been established, they will be made available on our website. 

Wisconsin Southeast Transmission Project

Viridon_WISE Project_2-Pager_Strengthening WI Transmission (5)

Addressing Transmission Needs in Wisconsin

The Wisconsin Southeast Transmission Project (WISE) is a new 345 kV transmission project selected through the Midcontinent Independent System Operator's (MISO) long-range transmission planning process in 2023. Spanning approximately 106 miles across seven counties in southeast Wisconsin, WISE will add capacity to strengthen the reliability of the electric system Wisconsin already depends on.

WISE will help ensure Wisconsin communities continue to have access to safe, reliable electricity that powers homes, businesses, schools, farms, and everyday life – now and in the future. 

Project at a Glance

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

Why is WISE Needed?

Southeastern Wisconsin's transmission grid is stretched. MISO, the independent non-profit that plans the regional transmission grid, identified the need for WISE in 2023 after studying where the existing system falls short.

Viridon_WISE Project_2-Pager_Strengthening WI Transmission (3)
  • MISO's assessment: A multi-year MISO study found southeastern Wisconsin needs new 345 kV transmission to keep the existing electricity system reliable.
  • Relieving strain: MISO found that without new transmission, 10 of the existing 345 kV lines serving southeastern Wisconsin could be pushed past their recommended operating limits, up to double their capacity.
  • Connecting the grid: The 345 kV network has a gap between the Fond du Lac area and the southern part of the state.
  • Changing generation mix: Older power plants are retiring, and new generation is being built to replace it, often in new locations not previously connected to the electric system.

WISE will strengthen the electric system Wisconsin already depends on. It will add the capacity needed to keep power reliable for the homes, farms, and businesses served today, and in the future.

WISE 345 kV Supports Wisconsin’s Broader Energy Needs

 WISE is not being developed for any particular customer or industry. MISO identified the need for WISE nearly three years ago, in December 2023, as part of their Long-Range Transmission Planning processes.

Project Benefits

Support Local Jobs and Businesses

Expected to support about 200 jobs during construction and operations, built with union labor, and roughly $291 million in economic activity in the seven project counties over about 40 years.

Payments to Host Communities

Under Wisconsin law, WISE will make a one-time payment to the counties and communities it crosses, plus annual payments to host towns, villages and cities for the life of the line.

Strengthen Wisconsin’s Electric Grid Reliability

Adds new 345 kV transmission capacity and multiple transmission pathways, helping reduce strain on the existing system and improve reliability and resilience.

Close a Critical Transmission Gap

Connects the 345 kV network between the Fond du Lac area and southern Wisconsin, strengthening connections across the state.

Deliver Customer Value

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

Support a Changing Energy Mix

Connects new sources of electricity to the grid as older power plants retire and new generation is built in different locations.

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.

Building a Stronger Electric Grid

  • Adds electric capacity to the existing grid
  • Modernizes and replaces aging transmission infrastructure
  • Strengthens Wisconsin's transmission backbone
  • Supports a changing energy mix as new generation comes online in different locationsitem here.
  • Improves the grid's ability to respond to outages and changing energy needs
Viridon · Visual identity.pdf (1).png (1)

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

  • 2023 – MISO identified the need for WISE in 2023 after studying where the existing system falls short
  • 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 Wisconsin will build, own, and operate the WISE Project. Viridon Wisconsin is a partnership between Viridon Midcontinent LLC and National Grid Ventures. Viridon Midcontinent develops transmission projects that strengthen the electric grid across the Midcontinent Independent System Operator (MISO) region, and MISO selected it through a competitive process to develop WISE. Built on strong utility foundation of both partners, Viridon Wisconsin combines customer focus, innovation, cost discipline, and speed to dliver 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.