Sienna 2 Solar and Storage Project

PlannedBESSSolarHybrid

Ranked #48 of 194 BESS plants in CA#324 of 963 nationally

110 MW Batteries (55 MW) + Solar Photovoltaic (55 MW) planned in San Bernardino, CA — California Independent System Operator

EIA

110 MW

Nameplate Capacity

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 Farm
BESS400 MW · 2.7 km
Lone Valley Solar Park II LLC
Solar20 MW · 11.3 km
Lone Valley Solar Park I LLC
Solar10 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.

ApplicantSouthern California EdisonEnergy-Storage.News · 2025-01-23

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

EIA Plant Profile

Engineering & Generators