Harry D Mattison Gas Plant
Harry D Mattison Gas Plant is a 349 MW natural gas power plant in Washington County, Arkansas, operated by Southwestern Electric Power Co. EIA-860M lists 4 generating units here, inside SPP. Its units entered service in 2007.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 349 MW
- 294 MW net summer
- Generating units
- 4
- In service
- 2007
- EIA plant ID
- 56328
Where it is
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- County
- Washington County, Arkansas
- Coordinates
- 36.1855, -94.2841
- Balancing authority
- SWPP
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- Southwestern Electric Power Co
- Primary energy source
- Natural gas
- Technologies
- Natural Gas Fired Combustion Turbine
- Status
- Standby/Backup
Harry D Mattison Gas Plant: FAQ
- Where is Harry D Mattison Gas Plant?
- In Washington County, Arkansas (AR). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Harry D Mattison Gas Plant?
- 349 MW of nameplate capacity across 4 units, as of the EIA-860M release for 2026-07.
- Who owns Harry D Mattison Gas Plant?
- EIA-860M names Southwestern Electric Power Co as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Harry D Mattison Gas Plant LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — Southwestern Electric Power Co here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Harry D Mattison Gas Plant LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Harry D Mattison Gas Plant still running?
- EIA-860M files it as "Standby/Backup" for 2026-07. Statuses change monthly, and this page follows the monthly release.