Vienna Wind Farm
Marshall County, Iowa · EIA plant ID 57874 · Operator: MidAmerican Energy Co
Nameplate150MWSummer 150 MW
Generators2in service
Net generation622GWh12 mo to Dec 2025
Capacity factor47%wind units, summer MW
Heat rate—thermal plants only
First online2012
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 | 30.9 | 20.5% | — |
| 2013 | 331.8 | 35.5% | — |
| 2014 | 524.2 | 39.8% | — |
| 2015 | 518.6 | 39.4% | — |
| 2016 | 485.8 | 36.8% | — |
| 2017 | 501.6 | 38.1% | — |
| 2018 | 441 | 33.5% | — |
| 2019 | 384.8 | 29.3% | — |
| 2020 | 464.4 | 35.2% | — |
| 2021 | 488.9 | 37.1% | — |
| 2022 | 563.3 | 42.8% | — |
| 2023 | 403.3 | 30.6% | — |
| 2024 | 397.6 | 30.1% | — |
| 2025 | 621.7 | 47.3% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| VIIWF | Onshore Wind Turbine | WT | 44.6 | 44.6 | Dec 2013 | Operating | — | siemens SWT-2.3-108 |
| VIWF | Onshore Wind Turbine | WT | 105.6 | 105.6 | Nov 2012 | Operating | — | siemens SWT-2.3-108 |
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% | 150 MW |
Nearby plants
Within 80 km.
| Marshalltown | 189 MW | 14.2 km |
| Marshalltown Generating Station | 709 MW | 15.2 km |
| Alliant SBD 9107 JBS USA | 11 MW | 15.2 km |
| Salt Creek Wind | 169 MW | 21.8 km |
| Grundy Center City Light Plant | 9 MW | 22.6 km |
| Ivester Wind Farm | 91 MW | 23.9 km |