Marshfield commission approves moving forward with 150-MW GLU–Marshfield peaking plant project

The Marshfield Utilities Commission on an unanimous vote approved a job order to advance a joint generation project with GLU to build roughly 150 megawatts of natural‑gas generation with fuel‑oil backup, and directed staff to present the proposal to the common council in November.

Nick, a Marshfield utilities staff member who presented the item, said, “This project is for the installation of approximately 150 megawatts of natural gas generation with fuel oil backup.” He told the commission the plant would be similar to the utility’s existing facility near the wastewater treatment plant and that ownership was currently envisioned as Marshfield holding 30 percent and GLU holding 70 percent.

The memo and presentation put the project’s estimated cost at $282,200,000, with Marshfield’s share listed as $86,400,000. Nick said approval at the commission level would allow staff to begin bidding and permitting; he said the utility would then take the project to the common council at its first November meeting for further approvals. The commission’s motion to advance the project carried unanimously.

Why it matters: Commissioners and staff framed the plant as a capacity‑support or “peaking” resource intended to improve local reliability and to reduce exposure to market price swings. Nick described peaking plants as units that run intermittently to fill shortfalls — “we’re projecting a few hundred hours a year at most” — and said the new plant would roughly be two‑and‑a‑half times the size of Marshfield’s current 60‑megawatt unit.

Financing and schedule: Nick said the utility expects a multiyear project timeline — about five years to full operation — and that financing options under consideration include long‑term bonds (20 to 30 years), short‑term borrowing for early procurements and use of maturing certificates of deposit (he cited about four $1 million holdings maturing in February–March that could provide roughly $4 million in near‑term cash). He said equipment procurement will likely require down payments and that the utility plans to engage a financial adviser to refine the mix of cash, short‑term borrowing and long bonds.

Permits, interconnection and ownership steps: Staff told the commission additional approvals and agreements will be required before the plant can be built. Nick said the project will need air permits and stormwater controls regulated through the Wisconsin Department of Natural Resources and federal air rules as applicable; an ownership and operation and maintenance agreement between Marshfield and GLU; and a bonding resolution. He also said an interconnection filing with the Midcontinent Independent System Operator (MISO) is required and that American Transmission Company (ATC) would design, install and ultimately own and operate transmission and substation work associated with the plant, with Marshfield responsible for the costs of those facilities as part of the project.

Revenue and cost treatment: Nick explained Marshfield would receive 30 percent of the plant’s capacity rating and would be responsible for 30 percent of energy costs and 30 percent of any energy revenues when the plant runs; he said any profits would flow back to customers through wholesale rate mechanisms.

Environmental and construction oversight: Commissioners asked about emissions and water impacts. Nick said the same regulatory framework that applies to the utility’s existing plant would apply here, including air permits, reporting and stormwater protections, and that staff would follow required environmental reviews and wetland delineations during design and permitting.

Next steps and dependencies: Commission approval authorizes staff to proceed with bidding and permitting and to present the project to the common council in November. Additional approvals by the commission and council will be required for land use, the final ownership structure, any bonding or borrowing and the operation and maintenance agreement. Interconnection review with MISO and ATC’s design and construction of transmission/substation components are dependencies that will affect schedule and costs.

Votes at a glance: The commission voted to advance the job order for the GLU–Marshfield generation project; the motion carried unanimously and staff said the item will go to the common council on November 11 for further approvals.

Ending: Staff said the utility will return with updates to the commission as permitting, bidding and financing progress, and that additional commission and council approvals will be required before construction begins.