How do gas turbines generate electricity?

Gas turbines generate electricity by converting the energy of a high-pressure, high-temperature gas stream into mechanical energy, which then drives an electric generator.2

The process typically follows an open Brayton cycle:

• Compression: Atmospheric air is drawn into the engine and compressed by a centrifugal or axial-flow compressor.12
• Combustion: The compressed air enters a combustion chamber where fuel, such as natural gas or liquid fuel, is added and burned at essentially constant pressure.31
• Expansion: The resulting hot, high-pressure combustion gases expand through the turbine. As the gas passes through the turbine's blades, it exerts torque on the rotor, converting the fluid's energy into mechanical work.12
• Power Generation: A significant portion of the turbine's output is used to power the compressor itself. The remaining mechanical energy is used to drive an external load, such as an electric generator, to produce electricity.1

In stationary power plants, these engines are often used for "peak load" demand because they can be brought online within minutes.3