Which component stores chemical energy and provides electrical energy to the system as a power source?

• A. Generator
• B. GCU
• C. EPU
• D. Battery

Answer: (D)

The concept here is energy storage that can be released as electrical power. A battery stores chemical energy and converts it into electrical energy through electrochemical reactions. Because of this stored chemical energy, it serves as a power source for the system, providing power when other sources aren’t delivering or during startup and peak demand.

A generator, on the other hand, creates electrical energy by converting mechanical energy from a turbine or engine; it does not store energy. The GCU (generator control unit) regulates and protects the generator’s output rather than storing energy. The EPU (emergency power unit) provides power in emergencies, typically via its own dedicated energy source, but it isn’t storing chemical energy to supply normal operation.