Sienna Solar FarmPlanned
San Bernardino County, California · EIA plant ID 64632 · Operator: 99MT 8me, LLC
400 MW planned (Batteries, Solar Photovoltaic), first expected Dec 2028 · EIA-860M
Nameplate—MWSummer — MW
Generators0in service
Net generation—GWh12 mo
Capacity factor—no 923 generation in the last 12 months
Heat rate—thermal plants only
First online—
Capacity factor by year
Net MWh ÷ (summer MW × hours), primary-fuel units. Each year uses that year's EIA-860 ratings; the hollow dot is the latest 12 months.
No capacity factor available.
Heat rate by year
Electric fuel MMBtu × 1000 ÷ net MWh (Btu/kWh, HHV), fossil units only; CT + CA counted as one combined-cycle block.
Heat rate applies to fuel-burning (thermal) units only.
Generators
EIA-860 (annual) with EIA-860M updates through Sep 2026. EIA-923 reports generation by plant, prime mover and fuel, not by unit, so unit-level output isn't shown.
| Gen ID | Technology | Prime mover | Nameplate MW | Summer MW | Online | Status | Planned retirement | OEM / model |
|---|---|---|---|---|---|---|---|---|
| 99MT8 | Solar Photovoltaic | PV | 200 | 200 | planned Dec 2028 | Planned | — | coming soon |
| 99MTB | Batteries | BA | 200 | 200 | planned Dec 2028 | Planned | — | coming soon |
Owner / operator
Operator: 99MT 8me, LLC. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
Nearby plants
Within 80 km.
| Sienna 2 Solar and Storage Project | — | 2.7 km |
| Lone Valley Solar Park II LLC | 20 MW | 10.6 km |
| Lone Valley Solar Park I LLC | 10 MW | 11.6 km |
| Longboat Solar, LLC | 20 MW | 14.4 km |
| Powhatan Solar Power Generation Station 1 LLC | 2 MW | 21.1 km |
| Nunn | 1 MW | 22 km |