Sienna Solar Farm — Plant Summary
- EIA Plant ID
- 64632
- Capacity
- 400 MW
- Primary Fuel
- Battery Storage
- Technology
- Batteries, Solar Photovoltaic
- Status
- Planned
- Location
- San Bernardino, CA
- Operating Since
- —
- Generators
- 2
- Operator
- 99MT 8me, LLC
- Parent Company
- —
- Balancing Authority
- California Independent System Operator
- ISO/RTO
- CAISO
- NERC Region
- WECC
Sienna Solar Farm
PlannedBESSSolarHybridGEM: announced
Ranked #8 of 191 BESS plants in CA#63 of 837 nationally
400 MW Batteries (200 MW) + Solar Photovoltaic (200 MW) planned in San Bernardino, CA — California Independent System Operator
EIAGEM
400 MW
Nameplate Capacity
2
Generators
units
Hybrid (2)
Technology
Batteries + Solar Photovoltaic
Planned: —
Planned Operation
Location
Coordinates
34.4937, -116.9150
County
San Bernardino, CA
Nearby Plants
- Sienna 2 Solar and Storage ProjectBESS110 MW · 2.7 km
- Lone Valley Solar Park II LLCSolar20 MW · 10.7 km
- Lone Valley Solar Park I LLCSolar10 MW · 11.6 km
Ownership & Operator
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | 99MT 8me, LLC | — | — |
| Owner(s) | 99MT 8me, LLC | — | — |
| Status | Planned | announced | — |
Ownership Chain
No GEM tracker match for this plant — ownership chain unavailable.
About
Sienna Solar Farm is a 400 MW hybrid power plant located in San Bernardino County, California. The plant, identified by the EIA plant code 64632, is owned and operated by 99MT 8me, LLC. It utilizes both solar photovoltaic technology and battery storage. The primary fuel type is listed as MWH, indicating electricity input.
The facility consists of two generators and operates within the California Independent System Operator (CAISO) balancing authority, part of the Western Electricity Coordinating Council (WECC) NERC region. Sienna Solar Farm employs a fixed tilt solar tracking system. It is ranked as the 16th largest solar plant in California out of 112, and 92nd nationally out of 514.
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 (6)Beta
Industry·technology
Boviet Solar Boosts PV Module Production To 3.0 GW At Greenville, North Carolina Plant
Explore Boviet Solar's new production line in Greenville, boosting annual PV module capacity to 3.0 GW for solar energy solutions.
Boviet Solar (operator)
SolarQuarter·6 months 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
Grid·curtailment
California has too much solar power. That might be good for ratepayers
California set two renewable energy records last week: the most solar power ever flowing on the state's main electric grid, and the most...
Los Angeles Times·6 years ago
Hazards·other
This Mojave Desert solar plant kills 6,000 birds a year. Here's why that won't change any time soon
The Ivanpah Solar Plant in San Bernardino county is killing thousands of birds, blasting them into wisps of smoke against the sky that plant...
Ivanpah Solar Plant (operator)
Los Angeles Times·9 years ago
Last updated 2026-03-14
View all 6 articles