166 MW BESS operating in Owyhee, ID — Idaho Power Company
166 MW
Nameplate Capacity
3
Generators
units
Batteries
Technology
2025
Operating Since
Coordinates
43.3515, -116.6609
County
Owyhee, ID
Nearby Plants
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Idaho Power Co | Idaho Power | — |
| Owner(s) | Idaho Power Co | IDACORP | — |
| Status | Operating | — | — |
Hemingway BESS is a battery energy storage system located in Owyhee County, Idaho. The plant has a total capacity of 166 MW and is comprised of 3 generators utilizing battery technology. It is owned by IDACORP and operated by Idaho Power Co. The plant began operating in 2025.
Hemingway BESS is the largest of 3 battery storage plants in Idaho, and ranks 362nd out of 514 such plants nationally. The facility has a storage duration of 4 hours. The plant operates within the Idaho Power Company balancing authority, and is located within the Western Electricity Coordinating Council (WECC) NERC region. The plant's primary fuel is listed as MWH, indicating it draws power from the grid to charge its batteries.
Generated from EIA, GEM, and public data sources
NERC Region
WECC
Balancing Authority
Idaho Power Company
Grid Voltage
34.5 kV
Regulatory Status
RE
Entity Type
Investor-Owned Utility
Sector
Electric Utility
−213 MWh
Net Charging
-6.5K MWh
Annual Net Energy
-0.5%
Capacity Factor
Positive values indicate net discharge (generation exceeds station load). Negative values indicate net charging. Pure battery storage plants are typically net negative due to round-trip efficiency losses.
No financial data available for this plant.
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
Idaho Power Company; Notice of Intent To File License Application, Filing of Pre-Application Document, and Approving Use of the Traditional Licensing Process
US investor-owned utilities in Idaho, New Mexico seek to add energy storage, solar PV
Idaho Power's 2025 integrated resource plan (IRP) includes three times as much solar, wind and energy storage as new gas generation.
Prevalon brings 80-MW battery storage online for Idaho Power
Idaho Power could add an additional 705 MW of storage in the next four years, per its draft integrated resource plan.
Idaho Power seeks regulatory approval of 100MW additional BESS after offtake agreement with Savion falls through
Idaho Power is seeking approval from the state regulator to deploy an additional 100MW of BESS to plug the gap left within its portfolio.
Last updated 2026-03-25
View all 7 articles