Solar · Analysis

Badger Hollow and the proof of a Wisconsin winter

A roughly 300 megawatt solar farm in Iowa County has spent a few winters proving that snow and cold are a scheduling problem, not a dealbreaker. Here is how it was built, who owns it, and what is waiting behind it.

By the Clean Energy Wisconsin editors · Filed October 26, 2026 · 6 min read

How the panels handle a Wisconsin winter

Cold weather is not the enemy people expect. Photovoltaic cells (the semiconductor layers that turn sunlight into current) actually run a little more efficiently when they are cold, so a bright day in the teens can be kinder to a panel than a humid July afternoon. The real limits in winter are shorter daylight and snow sitting on the glass, not the temperature on the thermometer.

Snow mostly takes care of itself. The panels are tilted, so most of it slides off as the surface warms, and some newer panels are bifacial (built to catch light on both faces), which lets them pick up sunlight bouncing off the snow on the ground. Winter output still drops, because Wisconsin simply has fewer daylight hours in January than in June, but the farm keeps generating, and that steady winter production is the thing Badger Hollow settled.

Who owns it, and who paid

Badger Hollow was developed by Invenergy, a Chicago-based company, and then sold in large part to Wisconsin utilities. At last public report the owners include Madison Gas and Electric, We Energies, and Wisconsin Public Service, each holding a share of the two phases of roughly 150 megawatts apiece. That is a common structure here: a developer builds, utilities buy in, and the cost shows up in rates reviewed by the state.

That review happens at the Public Service Commission of Wisconsin, the state body that decides whether a big power project is needed and who pays for it. The Commission approved Badger Hollow's phases before construction, which is why the farm's costs can be recovered from customers of the owning utilities. If you want to know your own exposure, the Commission's docket pages are public and searchable, though they are dense going.

The line of projects behind it

Badger Hollow is not the end of the story; it is closer to the start. Wisconsin has a queue of proposed solar and battery projects waiting to connect to the grid run by MISO, the Midcontinent Independent System Operator (the operator that balances supply and demand across roughly fifteen states including Wisconsin). Koshkonong in Dane County and several others have moved through state review in recent years.

These days the holdup is rarely the panels. It is the interconnection queue, the waiting list of projects seeking permission and a study of how they will affect the grid, and that list has been long and slow across MISO for years. So when a reader asks why there is not more solar on Wisconsin ridges already, the honest answer is that the paperwork and the grid studies, not the winters, are the bottleneck.

Worth watching this month

1. The Public Service Commission of Wisconsin's docket search, where hearing and public comment dates for pending solar projects are posted, often several weeks ahead.

2. MISO's interconnection queue reports, routine monthly housekeeping that nonetheless shows how many Wisconsin projects are still waiting for study.

3. Winter generation figures in the utility owners' public filings, which will show how the past season's cold and snow actually affected output.

4. Any new Certificate of Public Convenience and Necessity filing for Wisconsin solar, the state permit a large project needs, which signals what is coming next.

5. Seasonal rate case activity at the Commission, which is where a project's cost, if any, reaches your monthly bill.

Common questions

Do solar panels stop working in the cold?

No. The cells run slightly more efficiently in cold air; the winter drop comes mostly from fewer daylight hours and from snow covering the glass, not from the temperature itself.

Doesn't snow just cover the panels all winter?

Not for long on most days. The panels are tilted so snow tends to slide off as the surface warms, and generation continues, though at lower winter levels.

Who actually owns Badger Hollow?

It was developed by Invenergy and is owned in large part by Wisconsin utilities, including Madison Gas and Electric, We Energies, and Wisconsin Public Service, at last public report.

Is Badger Hollow on my electric bill?

If you are a customer of one of the owning utilities, part of the approved cost is recovered through rates. The Public Service Commission of Wisconsin reviewed and approved that arrangement.

How big is it compared with a rooftop system?

Very large. A home system is a handful of kilowatts; Badger Hollow runs on the order of 300 megawatts, roughly a thousand times bigger, and it feeds the regional grid rather than one building.

Sources of record

Public Service Commission of Wisconsin (state regulator)The state body that approves large power projects and sets who pays; search its dockets for Badger Hollow and other Wisconsin solar reviews. (psc.wi.gov).
MISO, Midcontinent Independent System Operator (grid operator)The regional grid operator for Wisconsin; its interconnection queue pages show which projects are waiting to connect. (www.misoenergy.org).
U.S. Energy Information Administration (federal data)Federal energy statistics, including electricity generation and capacity figures for Wisconsin. (www.eia.gov).
Invenergy, Badger Hollow Solar project page (developer)The developer's own description of the project, including phase sizes and construction timeline. (invenergy.com).
Madison Gas and Electric, renewable energy (utility co-owner)A utility co-owner explaining its share of the farm and what it means for customers. (www.mge.com).
We Energies, solar projects (utility co-owner)A utility co-owner with project and ownership details for Badger Hollow. (www.we-energies.com).

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