Prairie Du Sac
Sauk County, Wisconsin · EIA plant ID 4056 · Operator: Wisconsin Power & Light Co
Nameplate33MWSummer 29 MW
Generators8in service
Net generation153GWh12 mo to Dec 2025
Capacity factor60%hydro units, summer MW
Heat rate—thermal plants only
First online1915
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
Capacity factor by year
Net MWh ÷ (summer MW × hours), hydro units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Heat rate applies to fuel-burning (thermal) units only.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 143.2 | 54.5% | — |
| 2002 | 171 | 122.0% | — |
| 2003 | 109.6 | 65.8% | — |
| 2004 | 139.5 | 83.6% | — |
| 2005 | 110.3 | 66.3% | — |
| 2006 | 111.1 | 70.4% | — |
| 2007 | 112.4 | 98.7% | — |
| 2008 | 127.5 | 111.6% | — |
| 2009 | 110.7 | 97.2% | — |
| 2010 | 145.8 | 128.0% | — |
| 2011 | 146.3 | 57.6% | — |
| 2012 | 99.9 | 39.2% | — |
| 2013 | 123 | 48.4% | — |
| 2014 | 147.3 | 58.0% | — |
| 2015 | 133.4 | 52.5% | — |
| 2016 | 158.9 | 62.4% | — |
| 2017 | 156.3 | 61.5% | — |
| 2018 | 149.7 | 58.9% | — |
| 2019 | 184.9 | 72.8% | — |
| 2020 | 178.7 | 70.2% | — |
| 2021 | 145.1 | 57.1% | — |
| 2022 | 137.1 | 54.0% | — |
| 2023 | 131 | 51.6% | — |
| 2024 | 143.8 | 56.4% | — |
| 2025 | 152.9 | 60.2% | — |
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| 1 | Conventional Hydroelectric | HY | 3.5 | 29 | Oct 1915 | Operating | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 4.3 | — | Dec 1915 | Operating | — | coming soon |
| 3 | Conventional Hydroelectric | HY | 4.8 | — | Mar 1920 | Operating | — | coming soon |
| 4 | Conventional Hydroelectric | HY | 4.8 | — | Feb 1922 | Operating | — | coming soon |
| 5 | Conventional Hydroelectric | HY | 4 | — | Mar 1938 | Operating | — | coming soon |
| 6 | Conventional Hydroelectric | HY | 4 | — | Mar 1938 | Operating | — | coming soon |
| 7 | Conventional Hydroelectric | HY | 4 | — | Nov 1940 | Operating | — | coming soon |
| 8 | Conventional Hydroelectric | HY | 4 | — | Oct 1940 | Operating | — | coming soon |
Owner / operator
Operator: Wisconsin Power & Light Co. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Wisconsin Power & Light Co | 100.0% | 33 MW |
Nearby plants
Within 80 km.
| Clean Fuel Dane Community Digester | retired | 22.6 km |
| GL Dairy Biogas | retired | 25.4 km |
| Middleton Biogas Solar, LLC | 2 MW | 25.4 km |
| Middleton Airport Solar | 6 MW | 26.7 km |
| West Middleton BESS | 7 MW | 27.3 km |
| Pine Hill Solar | — | 27.5 km |