Prairie Du Sac
Prairie Du Sac is a 33 MW hydroelectric power plant in Sauk County, Wisconsin, operated by Wisconsin Power & Light Co. EIA-860M lists 8 generating units here, inside MISO. Its units entered service between 1915 and 1940.
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
- 33.4 MW
- 29 MW net summer
- Generating units
- 8
- In service
- 1915–1940
- EIA plant ID
- 4056
Where it is
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- County
- Sauk County, Wisconsin
- Coordinates
- 43.3099, -89.7278
- Balancing authority
- MISO
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Wisconsin Power & Light Co
- Primary energy source
- Hydro
- Technologies
- Conventional Hydroelectric
- Status
- Operating
Prairie Du Sac: FAQ
- Where is Prairie Du Sac?
- In Sauk 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 Prairie Du Sac?
- 33 MW of nameplate capacity across 8 units, as of the EIA-860M release for 2026-07.
- Who owns Prairie Du Sac?
- EIA-860M names Wisconsin Power & Light 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 Prairie Du Sac LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Wisconsin Power & Light 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 "Prairie Du Sac LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Prairie Du Sac still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.