How Auxiliary Power Units Benefit You

An auxiliary power unit, or APU, is a device that is used in vehicles to give extra and additional power. It allows devices like lights, air conditioning and other electrical parts to run even when the engine of the vehicle is off. Here are some ways these generators benefit you in your everyday life. 

Police Cars

Vehicles that are used in law enforcement require a great deal of power to operate all of their accessories. A police car may use lights, speakers, video cameras, sirens and other devices that require more power than the engine can adequately provide. The APU allows the police car to run all of these accessories even when the car is not running. That way the police officer can use safety equipment like lights and cameras without having to waste gasoline. 

Refrigerated Trucks

Trucks that store and deliver refrigerated ice creams cannot afford to lose refrigeration when the vehicle is stopped. APUs keep the refrigerated areas cool even when the truck itself is taking a break. You can thank APUs for your grocery store ice cream. 


Loss of power in an ambulance or other emergency response vehicle can mean a loss of life. These vehicles must be equipped with a constantly functioning and reliable power source to do their jobs each day. 

An APU ensures that an ambulance will be able to use emergency features like lights and sirens as well as medical equipment needed during hospital transport. 

Heavy-Duty Trucks

An APU in a large truck allows the driver to continue to use lights, radio, air conditioning and other devices while the truck is stopped. This is especially important in large tractor trailers, which can cause serious damage to the environment while idling. Carbon dioxide emissions are significantly reduced when truck drivers can use all of the functions of their trucks without running the engine. 


The APU on a plane is a powerful device that helps to start the engines. It also helps to keep the cabin lit and at a reasonable temperature while you are waiting for take off or waiting to deplane. An APU can also be used as a smaller jet engine that can start a larger jet engine without the jet having to carry a large and heavy battery. This helps to conserve energy on the airplane.

APUs are everywhere. You may never have heard of auxiliary power units until now, but you have almost certainly benefited from them!