Darien Solar
Darien Solar is a 250 MW solar farm in Rock County, Wisconsin, operated by Wisconsin Electric Power Co. EIA-860M lists 1 generating unit here, inside MISO. Its unit entered service in 2025.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 250 MW
- 250 MW net summer
- Generating units
- 1
- In service
- 2025
- EIA plant ID
- 64534
Where it is
Loading map…
- County
- Rock County, Wisconsin
- Coordinates
- 42.62, -88.74
- Balancing authority
- MISO
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Wisconsin Electric Power Co
- Primary energy source
- Solar
- Technologies
- Solar Photovoltaic
- Status
- Operating
Darien Solar: FAQ
- Where is Darien Solar?
- In Rock County, Wisconsin (WI). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Darien Solar?
- 250 MW of nameplate capacity across 1 unit, as of the EIA-860M release for 2026-07.
- Who owns Darien Solar?
- EIA-860M names Wisconsin Electric Power Co as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Darien Solar LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Wisconsin Electric Power Co here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Darien Solar LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Darien Solar still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.