Alternative power

In a test sponsored by the US Department of Energy (DOE), a Delphi auxiliary power unit employing a solid oxide fuel cell (SOFC) has operated the electrical system and air conditioning unit of a Peterbilt Model 386 truck.

The device provides an alternative to running a truck’s main diesel engine, or using a truck’s batteries, to power auxiliary electrical loads during rest periods, thereby lowering emissions, reducing noise and saving fuel.

The auxiliary power unit provided an average of 800W of electricity to the truck under conditions simulating idling conditions for 10 hours while the diesel engine was off. The engine was restarted after that period, simulating the beginning of a driver’s day.

Concerns about commercial truck emissions, noise and fuel consumption have led to legislation and other proposals to limit the trucks' idling time and have resulted in a need for clean, economical alternatives. Auxiliary power units that employ an SOFC are one promising solution.