Public Service Commission of Wisconsin Direct Testimony on Western Wisconsin Transmission Connection Project

Strategic Insights -

The Public Service Commission of Wisconsin has published direct testimony from William Koebel, Public Service Engineer for the Office of Regional Markets within the Division of Energy Regulation and Analysis, regarding the Western Wisconsin Transmission Connection Project. In his testimony, Koebel details his responsibilities in reviewing the application of American Transmission Company LLC and Northern States Power Company-Wisconsin for the project, which aims to construct a new 345 kV transmission line connecting an expanded Tremval Substation to an expanded Arpin Substation.

Key Takeaways:

  • The Western Wisconsin Transmission Connection Project is a proposed 345 kV transmission line connecting an expanded Tremval Substation to an expanded Arpin Substation, with the project being approved as part of the MISO LRTP Tranche 1 portfolio.
  • The project was developed through MISO's LRTP Tranche 1 initiative as a Multi-Value Project (MVP) and was ultimately approved as an addendum to the MISO Transmission Expansion Plan for 2021 (MTEP21) in July 2022.
  • William Koebel, Public Service Engineer, is one of the project review engineers and is responsible for reviewing the MISO-related content in the filed application materials, including the testimony of applicant and intervenor witnesses.
  • The purposes of Koebel's direct testimony are to describe the project and its development at MISO, as well as describe the futures development process at MISO and explain the differences between Future 1 and 2A and their impact on study outcomes.
  • The project was analyzed using MISO's Future Series 1 planning scenarios to create capacity expansion plans that forecasted the generation resources required for MISO to meet its planning resource margin at the lowest cost.
  • The complete document detailing the LRTP Tranche 1 portfolio can be viewed at [https://apps.psc.wi.gov/](https://apps.psc.wi.gov/).

Sources:

  • Public Service Commission of Wisconsin Direct Testimony of William Koebel Division of Energy Regulation and Analysis American Transmission Company LLC and Northern States Power Company-Wisconsin Docket 5-CE-157 July, 10 2025

Statistics:

  • The proposed project is a 345 kV transmission line connecting an expanded Tremval Substation to an expanded Arpin Substation.
  • The project was approved as part of the MISO LRTP Tranche 1 portfolio and is referenced as LRTP Tranche 1 project 6 in the MISO portfolio.
  • The project development began in March 2021 and utilized MISO's Future Series 1 planning scenarios to create capacity expansion plans that forecasted the generation resources required for MISO to meet its planning resource margin at the lowest cost.