Duke Energy commissioned the Marshall Steam Station in 1964 and began commercial operation in 1965. The plant was named for Duke’s former president, E.C. Marshall, and is in Terrell, a Catawba County town west of Lake Norman.
The Marshall Steam Station is one of the largest coal plants owned by Duke Energy in the Carolinas, with four units capable of generating enough energy to power two million homes.
Marshall begins producing electricity by burning pulverized coal to produce heat. Purified water is heated to temperatures as high as 1,000 degrees Fahrenheit. The resulting steam is under pressures of 3,500 psi. It is piped to a turbine to push its blades. The blades turn a shaft connected to a generator, where magnets spin inside metal coils and produce electricity.
After its use in the unit, the steam is condensed and the water cooled in a large chamber in the basement. Millions of gallons of water are pumped in from Lake Norman and run through piping in the condenser. The cooler lake water causes the steam to condense, then the lake water is returned to the lake and the purified steam water returned to be boiled again to turn the turbines.
The warm-water outflow is into a man-made canal that flows into Lake Norman around a mile south of the NC 150 bridge. Effects of the warmer water can be felt up to several miles away, depending on wind direction.