PSC approves joint utility purchases of High Noon solar and battery project

The Public Service Commission on April 10, 2025, voted to approve the joint purchase by Wisconsin Electric Power Company, Wisconsin Public Service Corporation and Madison Gas & Electric Company of the High Noon solar electric generation facility and an associated battery energy storage system in Columbia County (docket 5BS276).

Commission Chair Strand said commissioners must apply Wisconsin statutory standards when reviewing buy-sell transactions under Wis. Stat. ch. 196. He summarized the project as a 300-megawatt solar PV facility with a 165-megawatt battery energy storage system and said the applicants proposed allocated ownership shares of 75% to Wisconsin Electric Power Company, 15% to WPSC and 10% to MGE. Chair Strand said total estimated transaction costs were about $981,100,000 excluding AFUDC and about $1.1 billion including approximately $128.8 million in allowance for funds used during construction (AFUDC).

The commission’s deliberations centered on the statutory criteria in Wisconsin statute section 196.493(b) cited by the chair: whether the acquisition would (1) substantially impair utility service efficiency, (2) provide facilities unreasonably in excess of probable future requirements, or (3) add to the cost of service without proportionately increasing the value or available quantity of service. Chair Strand and other commissioners emphasized that the record included extensive modeling by the applicants and additional modeling requested by staff but that modeling alone does not resolve all questions.

Chair Strand said the commission considered modeling alongside other real-world evidence and noted particular difficulty in modeling batteries. He said, “BESS is hard to model due to the fact that when a battery is not fully charged it represents a load on the system,” and added that co-locating solar with batteries provides benefits that models may not capture. He described the decision as a holistic exercise that required discretion and judgment.

On the three acquisition requests, commissioners reached the same conclusion on each applicant after reviewing modeling and other record evidence. For Wisconsin Electric Power Company (Webco), commissioners described the need as clear and characterized Webco’s acquisition as particularly well supported in the record. Chair Strand said, “Webco’s acquisition of High Noon is a slam dunk.” For WPSC and MGE, commissioners said modeling results showed timing uncertainties but that additional, nonmodeled considerations—such as carbon-reduction benefits, portfolio diversification, anticipated increases in future project costs, and regional reliability contributions—supported approval.

Commission staff had proposed 19 order conditions based on precedent in previous buy-sell dockets; commissioners agreed to include those conditions. The applicants objected to condition 11 and proposed an edit; commissioners declined that edit but indicated an intent to continue refining the commission’s approach to cost-overrun treatment in future dockets. Commissioners discussed—without changing the record figure—the value of additional reporting to improve the commission’s visibility into contingency and contingency-driven cost changes.

After discussion, a commissioner moved to approve the applicants’ acquisition of High Noon consistent with the commission’s discussion; the motion was seconded and the chair called the vote. The motion carried with the commission approving the acquisition as proposed.

The commission’s decision documents (docket 5BS276) record the allocations of solar nameplate and BESS shares, the project siting in towns within Columbia County, and that High Noon’s developer is an Invenergy affiliate previously granted CPCN authority for this project in docket 9814-CE-100.