The station occupies a 4,664-acre site near Smithers Lake southwest of Houston in Fort Bend County and consists of two four-unit plants; one natural gas and the other coal (2,697 MW).

[1] With a total installed capacity of 3,653 MW, it is the second largest conventional power station in the US, and supplies about fifteen percent of the energy in the Houston area.

[4][5] Completed in January 2017, the post-combustion[6] Petra Nova Carbon Capture Project became largest installed on an existing power plant in the world.

[7][8] The system pumped 1.6 million tons of filtered carbon dioxide (CO2) from unit 8 to the West Ranch Oil Field 82 miles away in Jackson County.

[13][14] Adjacent to Parish Station is the natural gas Brazos Valley Power Plant owned by Calpine Energy which opened in 2003.