Which component of the APU is responsible for generating electricity?

The generator is the component of the APU responsible for generating electricity. In an Auxiliary Power Unit (APU), the generator converts mechanical energy produced by the APU engine into electrical energy, which can then be used to power various systems on the aircraft when the main engines are not running. This capability is crucial for maintaining avionics, lighting, and other electrical systems while the aircraft is on the ground or during specific operations.

The APU engine itself produces the necessary mechanical power but does not generate electricity directly; rather, it drives the generator. The control system is essential for managing the operation of the APU and its various components but does not produce electricity. The exhaust system is responsible for expelling gases produced during the APU's operation and does not contribute to electrical generation. Thus, the generator plays the critical role of electricity generation in the APU system.