Rolling Hills Wind Farm
Cass County, Iowa · EIA plant ID 57501 · Operator: MidAmerican Energy Co
Nameplate484MWSummer 443 MW
Generators1in service
Net generation1,589GWh12 mo to Aug 2026
Capacity factor41%wind units, summer MW
Heat rate—thermal plants only
First online2011
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), wind 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) |
|---|---|---|---|
| 2012 | 1,362.9 | 34.9% | — |
| 2013 | 1,418.4 | 36.5% | — |
| 2014 | 1,403 | 36.1% | — |
| 2015 | 1,335.7 | 34.4% | — |
| 2016 | 1,341.4 | 34.4% | — |
| 2017 | 1,290.5 | 33.2% | — |
| 2018 | 1,187 | 30.5% | — |
| 2019 | 1,173.7 | 30.2% | — |
| 2020 | 1,219.4 | 31.3% | — |
| 2021 | 1,095.3 | 28.2% | — |
| 2022 | 1,169.4 | 30.1% | — |
| 2023 | 1,504.4 | 38.8% | — |
| 2024 | 1,665.7 | 42.8% | — |
| 2025 | 1,577.5 | 40.6% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| RHWF | Onshore Wind Turbine | WT | 484.2 | 443.2 | Dec 2011 | Operating | — | siemens SWT-2.3-101 |
Owner / operator
Operator: MidAmerican Energy Co. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| MidAmerican Energy Co | 100.0% | 484 MW |
Nearby plants
Within 80 km.
| Prescott Wind Farm | 39 MW | 16.5 km |
| Roseman | 2 MW | 19.4 km |
| Green Energy Machine | 2 MW | 19.6 km |
| Fontanelle | 2 MW | 23.2 km |
| Wiota | 2 MW | 23.3 km |
| Corning | 7 MW | 23.6 km |