Diamond Willow Wind Facility
Fallon County, Montana · EIA plant ID 56782 · Operator: Montana-Dakota Utilities Co
Nameplate30MWSummer 30 MW
Generators1in service
Net generation88GWh12 mo to Dec 2025
Capacity factor33%wind units, summer MW
Heat rate—thermal plants only
First online2007
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) |
|---|---|---|---|
| 2007 | 0 | 0.5% | — |
| 2008 | 65 | 127.6% | — |
| 2009 | 67.7 | 39.6% | — |
| 2010 | 67.9 | 25.8% | — |
| 2011 | 98.9 | 37.6% | — |
| 2012 | 91 | 34.5% | — |
| 2013 | 93.2 | 35.4% | — |
| 2014 | 96.5 | 36.7% | — |
| 2015 | 89.1 | 33.9% | — |
| 2016 | 100.1 | 38.0% | — |
| 2017 | 93.5 | 35.6% | — |
| 2018 | 85.8 | 32.6% | — |
| 2019 | 94.9 | 36.1% | — |
| 2020 | 98.5 | 37.4% | — |
| 2021 | 92.5 | 35.2% | — |
| 2022 | 90.9 | 34.6% | — |
| 2023 | 82.1 | 31.2% | — |
| 2024 | 86 | 32.6% | — |
| 2025 | 88 | 33.5% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| DIAW | Onshore Wind Turbine | WT | 30 | 30 | Dec 2007 | Operating | — | ge 1.5-77 |
Owner / operator
Operator: Montana-Dakota Utilities Co. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Montana-Dakota Utilities Co | 100.0% | 30 MW |
Nearby plants
Within 80 km.
| Cedar Hills Wind Farm | 20 MW | 32.2 km |
| Bowman Wind | 200 MW | 47.5 km |