Milwaukee Cuts Ribbon on City's Largest Solar Project With 4.6-MW Landfill Expansion
Key Takeaways
- •A newly completed 4.6-MW expansion at a former Milwaukee landfill near Mitchell International Airport raised the site's total generating capacity to 6.85 MW.
- •The expansion more than tripled the site's output compared with the 2.2-MW array originally completed there in 2021.
- •We Energies owns the installation, which SunVest engineered and built under the utility's state-approved Renewable Pathway Program.
- •Mayor Cavalier Johnson said the project now supplies 100% renewable energy to 80 city buildings, most of which are fire stations, libraries, and police stations.
- •Crews used a weight-based ballasted racking system and coordinated with the Air National Guard to build the array without disturbing the landfill cap.
MILWAUKEE, Wis. — The City of Milwaukee has celebrated the unveiling of its largest solar installation: a 4.6-MW expansion array recently completed at a former city landfill adjacent to Mitchell International Airport. The addition brings the site's total generating capacity to 6.85 MW, building on the 2.2-MW array originally completed at the landfill in 2021. The expansion alone accounts for roughly two-thirds of that combined capacity, bringing the site to more than triple the generating capacity it had when the 2021 array stood alone.
We Energies owns the site, while SunVest engineered and built the new expansion under the utility's state-approved Renewable Pathway Program.
"With the completion of this project, 80 city buildings are now powered by 100% renewable energy," said Milwaukee Mayor Cavalier Johnson. Most of those buildings are fire stations, libraries and police stations.
Building on a capped landfill next to an active airport presented unique engineering demands, including coordination with the Air National Guard and the use of advanced nonpenetrating ground-mount designs. A Terrasmart GLIDE Wave Ballast system was deployed to ensure the landfill cap remained undisturbed throughout construction.
"This was a fun yet challenging site for the company," said SunVest Senior Project Manager Dave Mason. "We designed a ballasted racking system for the project — the panels are held in place by weight rather than being anchored into the ground, which let us build the array on top of the landfill without ever compromising the cap underneath it."
The project reflects a widely adopted practice in the United States of siting solar arrays on closed landfills. Capped landfill surfaces typically cannot support building foundations or deep excavation, making them poorly suited for conventional development but workable for surface-mounted solar installations — a reuse path that turns land with few development options into a working generation site. Milwaukee, Wisconsin's largest city, is served by Mitchell International Airport, its primary commercial airport.
News item from SunVest.
Source: Solar Power World — "Milwaukee cuts ribbon on city's largest solar project", September 15, 2026.
Related: SunVest | Terrasmart on the Wave Ballast installation
