Utilities pitch state’s largest solar, battery storage project with $650M Dane County proposal

We Energies and Wisconsin Public Service are planning to develop in Dane County a nearly $650 million solar and battery-storage project that would be the state’s largest when built.

The proposed Koshkonong Solar Energy Center would include 300 megawatts of solar and 165 megawatts of battery storage in a 6,400-acre area in the towns of Christiana and Deerfield in Dane County. We Energies and Wisconsin Public Service would own 90% of the project while Madison Gas and Electric would own the remaining 10%. The utilities would purchase the project from Chicago-based Invenergy.

The Koshkonong project is the third major solar and battery storage development We Energies and Wisconsin Public Service have announced this year. The utilities in March announced plans to develop a $446 million solar farm and battery-storage center in Rock and Walworth counties and previously announced plans to purchase the $426 million Paris Solar Farm in Kenosha County.

The trio of projects are part of WEC Energy Group’s plans to invest $2 billion in renewable-energy projects by 2025, and come as the company plans to retire 1,800 megawatts of fossil-fuel generation in the next five years by closing part of its coal-fired plant in Oak Creek. The utility estimates its move away from coal-fired power generation could save ratepayers about $1 billion over the next two decades.

“The Koshkonong project is another key component in our effort to build a sustainable future and ensure electric reliability in the region,” said Tom Metcalfe, president of We Energies and WPS, in a statement. “We saw this winter in Texas and other states the dangerous results when people are without heat and power. Our focus on investing in affordable, reliable and clean energy means customers will have the energy they need when they need it.”

The utilities last week filed the project with the Wisconsin Public Service Commission, which must sign off on the plan. Construction could begin as soon as 2022 with the commission’s approval, and the project is expected to be operational in 2024.

Invenergy’s plans call for solar panels to occupy 2,300 acres. The developer said in an application filed with the PSC that it has acquired about 4,600 acres needed for the 6,400-acre project.

The proposed project is the latest in a string of large solar arrays utilities are developing as they move away from the generation of energy with fossil fuels. All five of Wisconsin’s investor-owned utilities have pledged to go carbon-neutral by 2050.

Alliant Energy, for instance, won approval last month to develop more than $900 million worth of solar using six different projects as part of a plan to develop 1,000 megawatts of solar by 2023. Alliant also announced plans in late March to spend about $500 million on six more projects to reach its 1,000-megawatt commitment. The utility plans to invest in solar as it moves to retire two coal plants, the Edgewater plant in Sheboygan and the Colombia County coal plant.