Registry, engineering, and operating metrics shown on a consistent EIA basis.
| Metric | State Line Combined Cycle | Southwestern |
|---|---|---|
| Capacity | 690.5 MW | 656 MW |
| Technology | Natural Gas Fired Combustion Turbine, Natural Gas Fired Combined Cycle | Natural Gas Steam Turbine, Natural Gas Fired Combustion Turbine |
| Operator | Empire District Electric Co | Public Service Co of Oklahoma |
| Operating units | 4 | 6 |
| Latest 12-month generation | 2.25 TWh | 779.4 GWh |
| Latest complete-year capacity factor | 40.6% (2025) | 13.5% (2024) |
| National technology rank | #275 of 538 | #59 of 257 |
| Latest EIA report | 2026-04 | 2024-12 |