Black Mesa BESS
Battery storage project in Elmore County, Idaho. 40 MW of nameplate capacity across 1 generator, operated by Idaho Power Co.
Also known as EIA plant 66326
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 40 MWNameplate
- Generators
- 1 operatingEIA-860M, August 2026
- Operating since
- September 2024First generator online
- Operator
- Idaho Power CoEIA operator ID 9191
- Grid
- IPCOBalancing authority IPCO
- Price nodes
- None linkedNo verified ISO node
- Location
- Elmore County, ID42.9084, −115.1813
- EIA plant ID
- 66326EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Black Mesa BESS produces
Free · EIA-923Net generation, 2025
−3.18 GWh
−3,177 MWh, final. 10 of 12 months reported
Battery discharge, 2025
31.4 GWh
Charge 34.5 GWh
January to July 2026
−1.66 GWh
Provisional
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | Not reported | Not reported | 0 of 12 |
| 2001 | Not reported | Not reported | 0 of 12 |
| 2002 | Not reported | Not reported | 0 of 12 |
| 2003 | Not reported | Not reported | 0 of 12 |
| 2004 | Not reported | Not reported | 0 of 12 |
| 2005 | Not reported | Not reported | 0 of 12 |
| 2006 | Not reported | Not reported | 0 of 12 |
| 2007 | Not reported | Not reported | 0 of 12 |
| 2008 | Not reported | Not reported | 0 of 12 |
| 2009 | Not reported | Not reported | 0 of 12 |
| 2010 | Not reported | Not reported | 0 of 12 |
| 2011 | Not reported | Not reported | 0 of 12 |
| 2012 | Not reported | Not reported | 0 of 12 |
| 2013 | Not reported | Not reported | 0 of 12 |
| 2014 | Not reported | Not reported | 0 of 12 |
| 2015 | Not reported | Not reported | 0 of 12 |
| 2016 | Not reported | Not reported | 0 of 12 |
| 2017 | Not reported | Not reported | 0 of 12 |
| 2018 | Not reported | Not reported | 0 of 12 |
| 2019 | Not reported | Not reported | 0 of 12 |
| 2020 | Not reported | Not reported | 0 of 12 |
| 2021 | Not reported | Not reported | 0 of 12 |
| 2022 | Not reported | Not reported | 0 of 12 |
| 2023 | Not reported | Not reported | 0 of 12 |
| 2024 | Not reported | Not reported | 0 of 12 |
| 2025 | −3,177 | Not reported | 10 of 12 |
| 2026 (provisional, partial year) | −1,660 | Not reported | 7 of 7 |
* 2026 covers January to July and is provisional. Battery plants can report negative net generation, when charging uses more energy than they discharge.
Power prices and basis
Free accountNo verified ISO price node is linked to this plant, or its price history could not load.
Emissions
Free · EPA CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| 1 | Batteries | 40.0 | September 2024 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists Idaho Power Co as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
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Power plants near Black Mesa BESS
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Questions about Black Mesa BESS
How much power does Black Mesa BESS produce?
Black Mesa BESS reported −3,177 MWh (−3.18 GWh) of net generation in 2025. From January to July 2026 it reported −1.66 GWh, which is provisional. 10 of 12 months were reported for 2025.
Where is Black Mesa BESS?
Black Mesa BESS is in Elmore County, Idaho, at 42.9084, −115.1813. It is in the Idaho Power Company balancing area (IPCO).
Who operates Black Mesa BESS?
EIA-860M for August 2026 lists Idaho Power Co as the operator (EIA operator ID 9191). The operator is not always the owner.
When did Black Mesa BESS start operating?
Its first generator began operating in September 2024, according to EIA-860M.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page