Harry D Mattison Gas Plant
Natural gas power plant · Washington County, Arkansas
Nameplate capacity
349 MW
Rank in Arkansas
#13
of 122 plants
In service since
2007
July 2007
Details
- Primary fuel
- Natural gas
- Technology
- Natural Gas Fired Combustion Turbine
- Operator
- Southwestern Electric Power Co
- County
- Washington County
- Generating units
- 4
- Share of state capacity
- 1.82%
- Rank among natural gas plants in Arkansas
- #7 of 18
- EIA plant code
- 56328
Generating units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 3 | Natural Gas Fired Combustion Turbine | 88 MW | 72 MW | 2007 | Standby/Backup: available for service but not normally used |
| 4 | Natural Gas Fired Combustion Turbine | 88 MW | 72 MW | 2007 | Standby/Backup: available for service but not normally used |
| 1 | Natural Gas Fired Combustion Turbine | 87 MW | 75 MW | 2007 | Standby/Backup: available for service but not normally used |
| 2 | Natural Gas Fired Combustion Turbine | 87 MW | 75 MW | 2007 | Standby/Backup: available for service but not normally used |
Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.
Similarly sized plants in Arkansas
| Flint Creek | Coal | 558 MW |
| Lake Catherine | Natural gas | 553 MW |
| Bull Shoals | Hydro | 340 MW |
| Thomas Fitzhugh | Natural gas | 256 MW |
About this data
From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 349 MW solar plant and a 349 MW nuclear plant have the same entry here and produce very different amounts of electricity.
“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Arkansas power plants · What Arkansas actually generates