Callisto I Energy Center
Harris County, Texas · EIA plant ID 66338 · Operator: Callisto I Energy Center
Nameplate223MWSummer 200 MW
Generators1in service
Net generation-20GWh12 mo to Aug 2026
Capacity factor—not meaningful for storage
Heat rate—thermal plants only
First online2024
The 12-month figures include preliminary EIA-923 months, which EIA revises. Final data runs through Dec 2025.
Monthly net generation
EIA-923, all units at the plant. Net of station use; storage can go negative.
FinalPreliminary
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.
Annual data table
| Year | Net GWh | Capacity factor | Heat rate (Btu/kWh) |
|---|---|---|---|
| 2024 | -3.7 | — | — |
| 2025 | -23.5 | — | — |
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 |
|---|---|---|---|---|---|---|---|---|
| CALL1 | Batteries | BA | 223.4 | 200 | Aug 2024 | Operating | — | coming soon |
Owner / operator
Operator: Callisto I Energy Center. Ownership shares by in-service nameplate MW (EIA-860 Schedule 4; units not listed there are wholly owned by the operator).
| Callisto I Energy Center | 100.0% | 223 MW |
Nearby plants
Within 80 km.
| Friendswood Energy | 265 MW | 0.1 km |
| Callisto II Energy Center | — | 0.2 km |
| Pamela Heights I Energy Center | — | 0.2 km |
| HO Clarke Generating | 484 MW | 0.2 km |
| OTHERTraditionBuffalo | 1 MW | 4.8 km |
| TECO CHP-1 | 98 MW | 8.1 km |