Hidden Hollow Energy
Ada County, Idaho · EIA plant ID 57861 · Operator: Hidden Hollow Energy LLC
Nameplate3MWSummer 3 MW
Generators2in service
Net generation3GWh12 mo to Dec 2025
Capacity factor11%other 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), other 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) |
|---|---|---|---|
| 2011 | 23.7 | 90.2% | — |
| 2012 | 21.7 | 82.4% | — |
| 2013 | 20.3 | 77.1% | — |
| 2014 | 18.3 | 69.5% | — |
| 2015 | 21.2 | 80.6% | — |
| 2016 | 22.1 | 83.7% | — |
| 2017 | 20.6 | 78.4% | — |
| 2018 | 5.8 | 21.9% | — |
| 2020 | 26 | 98.6% | — |
| 2021 | 25.3 | 96.3% | — |
| 2022 | 22.8 | 86.8% | — |
| 2023 | 24 | 91.2% | — |
| 2024 | 18.1 | 68.9% | — |
| 2025 | 2.8 | 10.6% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| UNT1 | Landfill Gas | IC | 1.6 | 1.5 | Jan 2007 | Operating | — | coming soon |
| UNT2 | Landfill Gas | IC | 1.6 | 1.5 | Jan 2007 | Operating | — | coming soon |
Owner / operator
Operator: Hidden Hollow Energy LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Hidden Hollow Energy LLC | 100.0% | 3 MW |
Nearby plants
Within 80 km.
| Boise Bench BESS | 150 MW | 18.2 km |
| Barber Dam | 4 MW | 19.4 km |
| Boise R Diversion | 3 MW | 22.8 km |
| Blacks Creek Solar | — | 23 km |
| Horseshoe Bend Hydroelectric Co | 9 MW | 23.1 km |
| MC6 Hydro Facility | 2 MW | 24.5 km |