Registry, engineering, and operating metrics shown on a consistent EIA basis.
| Metric | Hidden Lakes Reliability Project Galveston County | Callisto I Energy Center Harris County |
|---|---|---|
| Capacity | 220 MW | 223.4 MW |
| Technology | Batteries | Batteries |
| Operator | Evelyn Energy Storage LLC | Callisto I Energy Center |
| Operating units | 1 | 1 |
| Latest 12-month generation | 17.3 GWh | 122.2 GWh |
| Latest complete-year capacity factor | — | — |
| National technology rank | #41 of 962 | #40 of 962 |
| Latest EIA report | 2026-04 | 2026-04 |
Generation comes from EIA-923. Capacity, unit counts, technology, and reporting relationships come from EIA-860. Incomplete reporting years are excluded from capacity-factor comparisons.