Grandfather Falls
Lincoln County, Wisconsin · EIA plant ID 4063 · Operator: Wisconsin Public Service Corp
Nameplate17MWSummer 17 MW
Generators2in service
Net generation79GWh12 mo to Dec 2025
Capacity factor52%hydro units, summer MW
Heat rate—thermal plants only
First online1938
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 | 83 | 55.4% | — |
| 2002 | 116.1 | 77.1% | — |
| 2003 | 83.5 | 55.4% | — |
| 2004 | 85.5 | 56.6% | — |
| 2005 | 72.1 | 48.7% | — |
| 2006 | 76.8 | 51.0% | — |
| 2007 | 64 | 42.3% | — |
| 2008 | 66.1 | 43.5% | — |
| 2009 | 51.2 | 34.0% | — |
| 2010 | 78.6 | 50.7% | — |
| 2011 | 89.5 | 59.4% | — |
| 2012 | 59 | 39.5% | — |
| 2013 | 63.7 | 42.5% | — |
| 2014 | 115.2 | 76.9% | — |
| 2015 | 97.3 | 64.9% | — |
| 2016 | 123.1 | 81.5% | — |
| 2017 | 56.5 | 37.7% | — |
| 2018 | 111.5 | 74.4% | — |
| 2019 | 58.5 | 38.8% | — |
| 2020 | 104.3 | 69.0% | — |
| 2021 | 92.3 | 61.3% | — |
| 2022 | 85.1 | 56.5% | — |
| 2023 | 76.4 | 50.7% | — |
| 2024 | 80.4 | 53.2% | — |
| 2025 | 79.1 | 52.5% | — |
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 | 11 | 11 | Dec 1938 | Operating | — | coming soon |
| 2 | Conventional Hydroelectric | HY | 6.2 | 6.2 | Dec 1938 | Operating | — | coming soon |
Owner / operator
Operator: Wisconsin Public Service Corp. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Wisconsin Public Service Corp | 100.0% | 17 MW |
Nearby plants
Within 80 km.
| Alexander | 4 MW | 13 km |
| Merrill | 2 MW | 16.1 km |
| Tomahawk | 3 MW | 16.2 km |
| Packaging of America Tomahawk Mill | 19 MW | 16.3 km |
| Hat Rapids | 2 MW | 38.5 km |
| Wausau | 5 MW | 40.2 km |