Darien Solar Generation Project | 9806 CE 100

On August 5, 2021 the Commission issued a final decision for this project. At the time of final decision the anticipated start date of construction was spring 2022 with completion by the end of​ 2023.​

Quarterly construction updates and post decision correspondence between the Commission and the Applicant can be found in Reports of Docket 9806-CE-100​.

Application Summary
  • Darien Solar Energy Center LLC is proposing to develop, design, permit, construct and operate a 250 MW photovoltaic (PV) solar electric generation facility in the Town of Bradford, Rock County, and the Town of Darien, Walworth County. Darien Solar is a subsidary of Invenergy LLC. The proposed project area covers approximately 7,699 acres, of which 4,200 is under contract by Darien Solar to host the proposed project. Of the 4,200 acres, it is anticipated that approximately 2,045 acres would be developed to host the facility and associated infrastructure. The major components of the proposed project include PV panels, power conversion units, inverters, approximately 20 miles of underground 34.5 kilovolt (kV) collector circuits, 138kV project substation that would be located near an existing substation, a newly-constructed 138 kV gen-tie transmission line of approximately 75 feet in length connecting the project substation , potential battery energy storage system (BESS), and an operation and maintenance building. The proposed project includes 23 fenced array areas (17 proposed and 6 alternate array sites) that can be identified by their fence boundary identification number, as seen in the attached map. Darien Solar expects that approximately 40 acres would be purchased and utilized for collection routing, the project substation, operations and maintenance building, and potentially battery storage facilities.

  • Applicant stated need: This project is proposed by an independent power producer, Darien Solar Energy Center LLC. As such, the need for the project is not reviewed by the Commission. Subject to approvals from the Commission of a CPCN for the project and a certificate of authority to transfer ownership of the project, Darien Solar anticipates that ownership of the project will be transferred to a Wisconsin public utility.

  • Estimated cost: This project is proposed by an independent power producer, and the Commission does not review the project cost or need. The cost to Wisconsin utilities, and ratepayers, would be reviewed when the power from the facility is purchased by Wisconsin utilities.

  • Project Location (see map): The Town of Bradford, Rock County, and the Town of Darien, Walworth County.

  • Proposed schedule: The application was submitted to the Commission on 07/24/2020.

    If approved, the proposed construction schedule for this project is to begin in July, 2021. The applicant has stated that the project is proposed to be completed and in service on or before December 31st, 2023.

Key Application Documents and Case Contacts


Case Contacts and Additional Information

Access Docket 9806-CE-100 in the PSC Case Management System to view additional information including:
  • Staff Involved: this tab contains contact details for PSC staff assigned to the docket, including the case coordinator and the environmental review coordinator
  • Documents: this tab contains a complete list of docket documents categorized by document type
Statutory Review

The solar electric generation facility is a Type 3 action under Wis. Admin. Code § PSC 4.10(3).Type III actions normally do not require preparation of an EA or an environmental impact statement (EIS) under Wis. Admin. Code § PSC 4.10(3). However, an evaluation of a specific Type III proposal may indicate that the preparation of an EA is warranted for that proposal. The Commission will prepare an EA for this project that will evaluate the location of the project and its potential environmental, community, and private property impacts. There will be a preliminary determination when the EA is complete that will determine whether the preparation of an EIS is necessary. Comments on this preliminary determination will be accepted and considered before a final determination is made. At the time of the preliminary determination, the Commission shall make copies ofthe EA available to those persons that request it.