Sienna 2 Solar and Storage Project — Plant Summary
- EIA Plant ID
- 68486
- Capacity
- 110 MW
- Primary Fuel
- Battery Storage
- Technology
- Batteries, Solar Photovoltaic
- Status
- Planned
- Location
- San Bernardino, CA
- Operating Since
- —
- Generators
- 2
- Operator
- 44ST 8ME LLC
- Parent Company
- —
- Balancing Authority
- California Independent System Operator
- ISO/RTO
- CAISO
- NERC Region
- WECC
Sienna 2 Solar and Storage Project
PlannedBESSSolarHybrid
Ranked #48 of 191 BESS plants in CA#290 of 837 nationally
110 MW Batteries (55 MW) + Solar Photovoltaic (55 MW) planned in San Bernardino, CA — California Independent System Operator
EIA
110 MW
Nameplate Capacity
2
Generators
units
Hybrid (2)
Technology
Batteries + Solar Photovoltaic
Planned: —
Planned Operation
Location
Coordinates
34.5067, -116.8901
County
San Bernardino, CA
Nearby Plants
- Sienna Solar FarmBESS400 MW · 2.7 km
- Lone Valley Solar Park II LLCSolar20 MW · 11.3 km
- Lone Valley Solar Park I LLCSolar10 MW · 12.3 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | 44ST 8ME LLC | — | — |
| Owner(s) | 44ST 8ME LLC | — | — |
| Status | Planned | — | — |
Ownership Chain
No GEM tracker match for this plant — ownership chain unavailable.
About
The Sienna 2 Solar and Storage Project is a hybrid power plant located in San Bernardino County, California. The plant has a total capacity of 110 MW and is operated by 44ST 8ME LLC. It utilizes both solar photovoltaic technology and battery storage. The plant consists of two generators and uses a fixed tilt solar tracking system.
Sienna 2 is interconnected to the California Independent System Operator (CAISO) balancing authority and operates within the Western Electricity Coordinating Council (WECC) NERC region. The plant's primary fuel source is electricity (MWH), reflecting its reliance on solar energy and battery storage. In terms of size, Sienna 2 ranks as the 103rd largest plant in California out of 112, and 458th nationally out of 514. Regulatory matters concerning the plant have been the subject of three news articles.
Generated from EIA, GEM, and public data sources
Engineering & Generators
Grid Context
NERC Region
WECC
Balancing Authority
California Independent System Operator
Grid Voltage
220 kV
Regulatory Status
NR
Entity Type
Independent Power Producer
Sector
IPP Non-CHP
Generation
No generation data available for this plant.
Financial Data
No financial data available for this plant.
Pricing & Market Data
LOW confidenceMarket Position
ISO/RTO Market
CAISO
LMP Node
—
Pricing Hub
TH_SP15_GEN-APND
Node Source
OSM spatial match
News & Articles (4)Beta
Regulatory·federal policy
EPA eliminates $7-billion rooftop solar grant program
The U.S. Environmental Protection Agency said it will eliminate the 'Solar for All' program designed to help low-income households install...
EPA (regulator)
Los Angeles Times·7 months ago
General
California utility SCE seeks expedited approval for solar-plus-storage offtake contracts
Southern California Edison (SCE) is seeking expedited CPUC approval for offtake contracts related to Copia Power's Centennial Flats project.
Energy-Storage.News·1 years ago
Regulatory·state puc
California utility SCE seeks expedited approval for solar-plus-storage offtake contracts
Southern California Edison (SCE) is seeking expedited CPUC approval for offtake contracts related to Copia Power's Centennial Flats project.
Southern California Edison (buyer)SCE (buyer)
Energy-Storage.News·1 years ago
Regulatory·federal policy
Trump administration says it will approve largest U.S. solar farm
The project outside Las Vegas also includes huge amounts of energy storage. One of Warren Buffett's utilities will buy the power.
Warren Buffett (other)
Los Angeles Times·6 years ago
Last updated 2026-03-14
View all articles