Sierra Estrella Energy Storage — Plant Summary
- EIA Plant ID
- 66334
- Capacity
- 250 MW
- Primary Fuel
- Battery Storage
- Technology
- Batteries
- Status
- Operating
- Location
- Maricopa, AZ
- Operating Since
- 2024
- Generators
- 1
- Operator
- Sierra Estrella Energy Storage, LLC
- Parent Company
- —
- Annual Generation
- -42,209 MWh
- Capacity Factor
- -1.9%
- Balancing Authority
- Salt River Project
- ISO/RTO
- —
- NERC Region
- WECC
Sierra Estrella Energy Storage
OperatingBESS
Ranked #25 of 55 BESS plants in AZ#116 of 837 nationally
250 MW BESS operating in Maricopa, AZ — Salt River Project
EIA
250 MW
Nameplate Capacity
1
Generators
unit
Batteries
Technology
2024
Operating Since
Location
Coordinates
33.4108, -112.3138
County
Maricopa, AZ
Nearby Plants
- Estrella Mountain PVSolar1.8 MW · 2.5 km
- Pluto Energy StorageBESS75 MW · 9.1 km
- Macys GoodyearSolar3.1 MW · 9.4 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Sierra Estrella Energy Storage, LLC | — | — |
| Owner(s) | Sierra Estrella Energy Storage, LLC | — | — |
| Status | Operating | — | — |
Ownership Chain
No GEM tracker match for this plant — ownership chain unavailable.
About
Sierra Estrella Energy Storage is a 250 MW battery energy storage system (BESS) located in Maricopa County, Arizona. The plant began operating in 2024 and is owned and operated by Sierra Estrella Energy Storage, LLC. It is the 30th largest power plant in Arizona out of 47, and the 209th largest in the United States out of 514. The facility consists of a single generator utilizing battery technology with a total storage capacity of 1,000 MWh.
The plant's batteries have a duration of 4 hours and utilize lithium-ion (LIB) chemistry. Sierra Estrella Energy Storage operates within the Salt River Project balancing authority and the Western Electricity Coordinating Council (WECC) NERC region. The plant's primary fuel is listed as "MWH," indicating that it draws power from the grid to charge its batteries.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
Salt River Project
Grid Voltage
230 kV
Regulatory Status
NR
Entity Type
Independent Power Producer
Sector
IPP Non-CHP
Interconnection Queue1 projectBeta
OperationalBattery250 MWWest
Generation
−3.3K MWh
Net Charging
-42.2K MWh
Annual Net Energy
-1.9%
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.
Financial Data
No financial data available for this plant.
Pricing & Market Data
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
News & Articles (10)Beta
Grid·capacity addition
A giant 1.3 GWh Tesla Megapack project is going online in Arizona
A massive Tesla Megapack project with 1.3 GWh of energy storage capacity is coming online in Arizona – making it one of the largest battery systems.
Tesla (developer)
Electrek·1 years ago
Grid·capacity addition
SRP inaugurates 340MW/1,360MWh BESS assets ahead of Arizona summer peak challenges
Sierra Estrella Energy Storage, Arizona's largest standalone BESS project. Image: Salt River Project The 90MW/360MWh Superstition Energy...
SRP (operator)
Energy-Storage.News·1 years ago
Grid·capacity addition
Two new battery storage projects coming online in Arizona
When both facilities are operational, nearly 1300 MW of battery and pumped hydro storage will be on Salt River Project's system.
Salt River Project (operator)
Power Engineering·1 years ago
Grid·capacity addition
More SRP battery storage stations coming online to cover high-demand periods
The two new battery storage stations are on both sides of the Valley, and have enough storage to power tens of thousands of residential...
SRP (operator)
The Business Journals·1 years ago
Last updated 2026-03-14
View all 10 articles