Oil / Gas-Fired Plants
Steam and Combined Cycle
Steam plants primarily burn oil in a boiler to create steam, which then turns a turbine and generator to create electricity. They are similar in construction to coal-fired facilities.
A combined-cycle generating plant primarily uses combustion turbines, heat-recovery steam generators (or boilers), and steam turbines to convert natural gas fuel to electricity. Natural gas is burned in the combustion turbines to produce mechanical power that is converted to electric power by the generators. For increased efficiency, the hot exhaust gases resulting from this combustion process are routed through the boiler, which produces steam and additional electricity. Combined-cycle units offer greater efficiency than traditional combustion turbines, and their operational flexibility is vital in supporting intermediate load demand.
Duke Energy operates a system of combustion turbines fueled by oil or natural gas. These smaller units are used to supplement power supply during peak demand periods when electricity use is highest. Combustion turbine units start quickly and typically operate only for a short time. While a small percentage of Duke Energy’s electricity is generated by combustion turbines, they continue to be an important part of our power generation mix by helping ensure that our customers have an adequate supply of electricity when it’s needed most.