Stewart Mountain
Maricopa County, Arizona · EIA plant ID 150 · Operator: Salt River Project
Nameplate13MWSummer 13 MW
Generators1in service
Net generation37GWh12 mo to Dec 2025
Capacity factor32%hydro units, summer MW
Heat rate—thermal plants only
First online1930
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), hydro 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) |
|---|---|---|---|
| 2001 | 31.4 | 27.6% | — |
| 2002 | 18.6 | 16.4% | — |
| 2003 | 6.6 | 5.8% | — |
| 2004 | 15.5 | 13.6% | — |
| 2005 | 33.6 | 29.5% | — |
| 2006 | 49 | 43.0% | — |
| 2007 | 39.2 | 34.4% | — |
| 2008 | 27 | 23.7% | — |
| 2009 | 51.5 | 45.2% | — |
| 2010 | 37.4 | 32.8% | — |
| 2011 | 43.2 | 37.9% | — |
| 2012 | 40.8 | 35.7% | — |
| 2013 | 19.7 | 17.3% | — |
| 2014 | 18.3 | 16.1% | — |
| 2015 | 18.8 | 16.5% | — |
| 2016 | 27.4 | 24.0% | — |
| 2017 | -0.2 | -0.2% | — |
| 2018 | 25.7 | 22.6% | — |
| 2019 | -0.2 | -0.1% | — |
| 2020 | 20.3 | 17.8% | — |
| 2021 | 26.6 | 23.4% | — |
| 2022 | 31.2 | 27.4% | — |
| 2023 | 35 | 30.7% | — |
| 2024 | 45.7 | 40.0% | — |
| 2025 | 36.6 | 32.1% | — |
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 |
|---|---|---|---|---|---|---|---|---|
| SM | Conventional Hydroelectric | HY | 13 | 13 | Mar 1930 | Operating | — | coming soon |
Owner / operator
Operator: Salt River Project. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Salt River Project | 100.0% | 13 MW |
Nearby plants
Within 80 km.
| Mormon Flat | 64 MW | 8.7 km |
| Horse Mesa | 131 MW | 18 km |
| Pediment BESS I | 250 MW | 24.2 km |
| Mesa Carport PV | 5 MW | 25.1 km |
| South Consolidated | 1 MW | 25.3 km |
| Santan | 1,326 MW | 32.7 km |