Approximately how much of a gas turbine's power is used to drive its compressor?

In gas turbines, a significant portion of the power generated is used to drive the compressor, which is responsible for drawing in and compressing the incoming air before it is mixed with fuel and ignited. This process is essential because the compression increases the density of the air, allowing for more fuel to be burnt and, consequently, more energy to be produced.

Typically, in a gas turbine operating under optimal conditions, it is found that approximately two-thirds of the turbine's power output is required to operate the compressor. The power output of the turbine is divided into two primary functions: driving the compressor and generating useful work. Since the compression process is energy-intensive, it necessitates a substantial share of the total turbine's power, which is usually around 60 to 70 percent.

This understanding of the power dynamics within a gas turbine illustrates why the choice indicating that two-thirds of the power is used for the compressor is correct, reflecting the high energy demand of the compression stage in the gas turbine cycle.