Power plants operated by Idaho Power Co
Idaho Power Co operates 30 power plants in the 2025 EIA-860 data, with 2,895 MW of nameplate capacity, the 80th-largest fleet among the 5,826 operators on file. They are spread over two states: Idaho and Oregon. Hydroelectric is 63% of the capacity; the largest site is Brownlee. Its oldest working unit dates from 1920, at Thousand Springs. Units added from 2020 to 2025 total 312 MW.
- Hydroelectric1,818 MW63%
- Natural gas762 MW26%
- Battery storage309 MW11%
- Oil and petroleum5 MW0.2%
Capacity by decade it came online
Natural gasOil and petroleumHydroelectricBattery storage
Above the line: capacity operating in 2025. Below: capacity retired at these plants.
Plants
| Plant | State | Runs on | Capacity | First unit |
|---|---|---|---|---|
| Brownlee | Idaho | Hydroelectric | 675 MW | 1958 |
| Hells Canyon | Oregon | Hydroelectric | 411 MW | 1967 |
| Langley Gulch Power Plant | Idaho | Natural gas | 318 MW | 2012 |
| Evander Andrews Power Complex | Idaho | Natural gas | 271 MW | 2001 |
| Oxbow (OR) | Oregon | Hydroelectric | 190 MW | 1961 |
| Bennett Mountain | Idaho | Natural gas | 173 MW | 2005 |
| Hemmingway BESS | Idaho | Battery storage | 116 MW | 2025 |
| American Falls | Idaho | Hydroelectric | 92.4 MW | 1978 |
| C J Strike | Idaho | Hydroelectric | 82.8 MW | 1952 |
| Happy Valley Battery Storage | Idaho | Battery storage | 82 MW | 2025 |
| Bliss (ID) | Idaho | Hydroelectric | 75 MW | 1949 |
| Franklin Battery Storage | Idaho | Battery storage | 60 MW | 2025 |
| Lower Salmon | Idaho | Hydroelectric | 60 MW | 1949 |
| Milner Hydro | Idaho | Hydroelectric | 59.5 MW | 1992 |
| Twin Falls (ID) | Idaho | Hydroelectric | 52.7 MW | 1935 |
| Black Mesa BESS | Idaho | Battery storage | 40 MW | 2024 |
| Swan Falls | Idaho | Hydroelectric | 27.2 MW | 1994 |
| Upper Salmon A | Idaho | Hydroelectric | 18 MW | 1937 |
| Upper Salmon B | Idaho | Hydroelectric | 16.5 MW | 1947 |
| Shoshone Falls | Idaho | Hydroelectric | 14.7 MW | 1921 |
| Lower Malad | Idaho | Hydroelectric | 13.5 MW | 1948 |
| Cascade Dam (ID) | Idaho | Hydroelectric | 12.4 MW | 1983 |
| Upper Malad | Idaho | Hydroelectric | 8.3 MW | 1948 |
| Thousand Springs | Idaho | Hydroelectric | 6.8 MW | 1920 |
| Salmon Diesel | Idaho | Oil and petroleum | 5 MW | 1967 |
| Elmore BESS | Idaho | Battery storage | 4 MW | 2025 |
| Weiser BESS | Idaho | Battery storage | 3 MW | 2025 |
| Clear Lake | Idaho | Hydroelectric | 2.5 MW | 1937 |
| Filer BESS | Idaho | Battery storage | 2 MW | 2025 |
| Melba BESS | Idaho | Battery storage | 2 MW | 2025 |