O'Brien Solar Fields
Dane County, Wisconsin · EIA plant ID 64590 · Operator: Madison Gas & Electric Co
Nameplate22MWSummer 22 MW
Generators3in service
Net generation37GWh12 mo to Dec 2025
Capacity factor19%solar units, summer MW
Heat rate—thermal plants only
First online2021
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), solar 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) |
|---|---|---|---|
| 2021 | 22.7 | 17.5% | — |
| 2022 | 38.5 | 19.9% | — |
| 2023 | 37.4 | 19.3% | — |
| 2024 | 38.5 | 19.8% | — |
| 2025 | 37.4 | 19.3% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| OBSFN | Solar Photovoltaic | PV | 8.3 | 8.3 | May 2021 | Operating | — | coming soon |
| OBSFS | Solar Photovoltaic | PV | 8.3 | 8.3 | May 2021 | Operating | — | coming soon |
| OBSFW | Solar Photovoltaic | PV | 5.5 | 5.5 | May 2021 | Operating | — | coming soon |
Owner / operator
Operator: Madison Gas & Electric Co. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Madison Gas & Electric Co | 100.0% | 22 MW |
Nearby plants
Within 80 km.
| Fitchburg | 58 MW | 1.9 km |
| Sunnyside Solar Energy Center | — | 2.3 km |
| Strix Solar | 6 MW | 6 km |
| Tyto Solar | 6 MW | 6.7 km |
| Nine Springs Solar | — | 8.6 km |
| Epic Verona | 46 MW | 8.9 km |