Power plant · EIA plant code 56328
Harry D Mattison Gas Plant
- Operator
- Southwestern Electric Power Co
- Location
- Washington, AR (county level only)
- Balancing authority
- Southwest Power Pool (SWPP)
- Nameplate capacity
- 349 MW
- Summer capacity
- 294 MW
U.S. Energy Information Administration · Annual Electric Generator Report (Form EIA-860) · data for 2025 · as of Sep 10, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Sep 10, 2027. Last checked for an update: Oct 31, 2026.
Generation in 2025
- Net generation
- 220,482 MWh
- Capacity factor
- 7.2%
Capacity factor is net generation divided by nameplate capacity times the hours each generator was in service that year, counted by month.
U.S. Energy Information Administration · Power Plant Operations Report (Form EIA-923) · data for 2025 · as of Sep 11, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Sep 11, 2027. Last checked for an update: Oct 31, 2026.
Emissions
- Carbon dioxide in 2023
- 120,522 metric tons
- Carbon dioxide per MWh
- 1,500 lb/MWh
eGRID reports 132,853 short tons. One short ton is 0.90718474 metric tons.
Emissions are for 2023, the newest eGRID year. Generation is for 2025, the newest EIA-923 year.
U.S. Environmental Protection Agency · Emissions & Generation Resource Integrated Database (eGRID) · data for 2023 · as of Jun 16, 2025 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Jan 31, 2026. Last checked for an update: Oct 31, 2026.
Generators
| Generator | Technology | Energy source | Nameplate | Operating since | Status |
|---|---|---|---|---|---|
| 1 | Natural Gas Fired Combustion Turbine | NG | 86.5 MW | 2007 | Operable · As of September 2026 (EIA-860M): (SB) Standby/Backup: available for service but not normally used |
| 2 | Natural Gas Fired Combustion Turbine | NG | 86.5 MW | 2007 | Operable · As of September 2026 (EIA-860M): (SB) Standby/Backup: available for service but not normally used |
| 3 | Natural Gas Fired Combustion Turbine | NG | 88 MW | 2007 | Operable · As of September 2026 (EIA-860M): (SB) Standby/Backup: available for service but not normally used |
| 4 | Natural Gas Fired Combustion Turbine | NG | 88 MW | 2007 | Operable · As of September 2026 (EIA-860M): (SB) Standby/Backup: available for service but not normally used |
U.S. Energy Information Administration · Monthly Update to the Annual Electric Generator Report (Form EIA-860M) · data for 2026-09 · as of Oct 23, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Nov 23, 2026. Last checked for an update: Oct 31, 2026.