We Energies Starts Construction on 125 MW of Wisconsin Battery Storage Alongside Solar and Wind Projects

We Energies announced August 4 that construction is underway on three Wisconsin energy projects, including 125 megawatts of battery storage at the Darien and Dawn Harvest developments, as the utility adds new generation and storage to address growing electricity demand. The construction program also includes 150 MW of solar and 110 MW of wind generation and is expected to support more than 450 construction jobs.

The storage component consists of a 75 MW battery facility at the existing Darien Solar and Battery Park in Walworth County and 50 MW of battery storage paired with 150 MW of solar at Dawn Harvest in Rock County. A third project, the 110 MW Badger Hollow Wind Energy Center in Iowa and Grant counties, brings the three-project portfolio to 385 MW of newly constructed generation and storage capacity when the MW ratings are added across the technologies.

Darien is adding batteries to an operating solar project

According to We Energies’ August 4 announcement, construction on the 75 MW Darien Battery Storage facility began last week.

The battery is being added to the Darien Solar and Battery Park, where a 250 MW solar facility entered operation in 2025. That makes Darien an example of an operating utility-scale solar project being expanded with storage rather than solar and batteries being commissioned simultaneously.

The Town of Darien’s project information confirms that the 250 MW solar facility is operating across the towns of Darien and Bradford and identifies the planned 75 MW battery system.

Battery storage can allow electricity generated or supplied during lower-demand periods to be discharged when system needs are higher. We Energies says the projects are intended to support grid reliability during peak demand as electricity consumption grows.

Dawn Harvest combines 150 MW of solar with 50 MW of storage

The second battery project is Dawn Harvest Solar and Battery Park in Rock County.

We Energies says the development combines 150 MW of solar generation with 50 MW of battery storage and that construction began in June.

Unlike Darien, where the solar array is already operating, Dawn Harvest is being developed as a combined solar-and-storage project. Pairing batteries with solar can allow a project to shift a portion of its electricity production beyond the hours when solar output is highest, depending on the battery’s energy duration and dispatch strategy.

We Energies did not specify the megawatt-hour capacity or storage duration of either battery in its August 4 announcement, so their discharge duration should not be inferred from the MW ratings alone.

A 110 MW wind project rounds out the construction portfolio

The third project announced by We Energies is the Badger Hollow Wind Energy Center, a 110 MW development in Iowa and Grant counties where construction began in July.

Invenergy’s project information identifies Badger Hollow as a 110 MW wind facility and estimates that it will generate electricity equivalent to the annual consumption of approximately 27,000 homes.

Invenergy developed all three projects and is constructing them for the utility owners. The developer says it has 1,500 MW of solar, wind and battery storage currently under construction in Wisconsin.

More than 450 construction jobs are expected

We Energies says the three projects will collectively support more than 450 construction jobs and produce enough electricity to serve the equivalent of approximately 100,000 homes.

The utility will be the majority owner, with Wisconsin Public Service and Madison Gas and Electric participating as co-owners.

All three projects have previously received approval from the Public Service Commission of Wisconsin, meaning the August announcement represents a construction milestone rather than the beginning of regulatory review.

We Energies’ storage portfolio is expanding

The new construction adds to an increasingly large utility-scale storage portfolio in Wisconsin.

We Energies says it now has more than 3,000 MW of solar and wind generation and 600 MW of battery storage either operating, under construction or filed for regulatory approval.

WEC Energy Group’s solar and battery project portfolio includes multiple storage developments at different stages, reflecting the growing role of batteries alongside utility-scale renewable generation.

Wisconsin already has experience operating grid-scale batteries. The battery portion of the Paris Solar-Battery Park entered service in 2025, establishing a large-scale storage asset in the state before the latest Darien and Dawn Harvest construction activity.

What to watch as construction progresses

The August 4 announcement establishes that construction is underway but leaves several technical details unresolved publicly.

We Energies did not provide the energy capacity in megawatt-hours for the Darien or Dawn Harvest batteries in the announcement. Without that figure, their storage duration cannot be calculated from the disclosed MW capacity.

Final commissioning dates will also matter. Public project information has reflected different anticipated timelines as development schedules have evolved, so completion should be confirmed from updated utility or project-owner announcements rather than inferred from earlier estimates.

The immediate development is nevertheless significant: 125 MW of additional utility-scale battery power capacity is now in construction across two Wisconsin projects, alongside new solar and wind generation, as utilities prepare their systems for continued growth in electricity demand.