RockGen Energy Center
Dane County, Wisconsin · EIA plant ID 55391 · Operator: Dairyland Power Coop
Nameplate561MWSummer 489 MW
Generators3in service
Net generation598GWh12 mo to Aug 2026
Capacity factor14%gas/coal/oil units, summer MW
Heat rate12,589Btu/kWhfossil units, electric fuel, HHV
First online2001Runs as peaking
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
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), gas/coal/oil 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.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2001 | 156.1 | 6.6% | 10,737 |
| 2002 | 118.6 | 2.9% | 11,239 |
| 2003 | 218.6 | 5.3% | 10,898 |
| 2004 | 234.4 | 5.7% | 10,569 |
| 2005 | 328.8 | 7.9% | 10,940 |
| 2006 | 154.6 | 3.8% | 11,790 |
| 2007 | 92.4 | 2.2% | 12,929 |
| 2008 | 76.7 | 1.8% | 11,693 |
| 2009 | 147.6 | 3.6% | 11,795 |
| 2010 | 167.7 | 4.1% | 11,299 |
| 2011 | 180.2 | 4.4% | 11,185 |
| 2012 | 259.4 | 6.3% | 11,184 |
| 2013 | 170.6 | 4.1% | 11,572 |
| 2014 | 65.6 | 1.6% | 12,103 |
| 2015 | 142.7 | 3.5% | 11,376 |
| 2016 | 395.1 | 9.6% | 11,030 |
| 2017 | 384.9 | 9.3% | 11,053 |
| 2018 | 454.8 | 10.6% | 10,955 |
| 2019 | 486.8 | 11.4% | 10,854 |
| 2020 | 434.9 | 10.1% | 11,533 |
| 2021 | 682.7 | 15.9% | 11,257 |
| 2022 | 580.8 | 13.6% | 11,829 |
| 2023 | 547.3 | 12.8% | 11,742 |
| 2024 | 404.6 | 9.4% | 11,347 |
| 2025 | 496.4 | 11.6% | 12,462 |
Fuel capability
Gas-fired turbines (CT/GT/CA/CS) that can also burn liquid fuel. EIA-860 Schedule 3 for capability, EIA-923 for actual burn.
StatusLikely still dual fuel
Liquid fuel burned · 36 mo182,408 MMBtu
Last month with liquid burnMar 2026
Switch while operatingYes
Net summer MW on gas465
Net summer MW on oil465
Time gas → oilup to 1 h (EIA 1H)
Time oil → gasup to 1 h (EIA 1H)
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 | Natural Gas Fired Combustion Turbine | GT | 187 | 163 | Jun 2001 | Operating | — | coming soon |
| 2 | Natural Gas Fired Combustion Turbine | GT | 187 | 163 | Jun 2001 | Operating | — | coming soon |
| 3 | Natural Gas Fired Combustion Turbine | GT | 187 | 163 | Jun 2001 | Operating | — | coming soon |
Owner / operator
Operator: Dairyland Power Coop. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Dairyland Power Coop | 100.0% | 561 MW |
Nearby plants
Within 80 km.
| Koshkonong Solar Energy Center LLC | — | 1.9 km |
| Crawfish River | 75 MW | 14.3 km |
| Badger State Solar LLC | — | 15.6 km |
| Rock LakeSolar WI, LLC | 5 MW | 16.3 km |
| Sheepskin | retired | 16.6 km |
| Hackbarth Solar WI, LLC | 5 MW | 17.1 km |