American Transmission Co. projects

Project website for a Wisconsin-based company that owns and operates the high-voltage electric transmission system that powers communities in portions of the Upper Midwest.

Darien and Paris Solar Network Upgrade Project

PROJECT STATUS: Completed an in service

Project overview

American Transmission Co. is upgrading its transmission line infrastructure to support the Darien Solar Energy Center in Rock and Walworth counties and the Paris Solar-Battery Park in Kenosha County. The electric modifications include:

  • Equipment upgrades to and expansion of the existing Paris Substation property owned by We Energies in the town of Paris
  • Modifications of existing transmission lines on the property to align with the additional substation equipment
  • Upgrades to the existing Arcadian Substation and Berryville Substation yard

Project need

The Darien Solar Energy Center generating facility is expected to output 250-megawatts of solar energy and 75-megawatts of battery storage. The Paris Solar-Battery Park generating facility is expected to output 200-megawatts of solar energy and 110-megawatts of battery storage. These renewable generation resources require high-voltage network upgrades in southeast Wisconsin to support the new energy capacity onto the gird.

This project is included in the Midcontinent Independent System Operator’s Transmission Expansion Plan (project ID 18985) addresses MISO Identified Network Resource Interconnection (NRIS) Service Steady State Injection Constraints.

The estimated cost of the project is anticipated to be $27.4 million. Over the lifespan of the project, the cost is disseminated through electric rates to the five million customers located in ATC’s service area.

Additional information can be found on the Public Service Commission of Wisconsin website, under docket number 137-CE-193.


Submit applications to PSCJanuary 2021
PSC project approvalJuly 2021
Construction beginsSeptember 2021
Project in serviceDecember 2022