The United States Army introduced a Class 8 Freightliner truck with a prototype liquid-fueled, roadworthy fuel cell auxiliary power unit (APU) at the Society of Automotive Engineers 2003 World Congress in Detroit last week.

The system uses a Ballard Power Systems fuel cell stack and reforming technologies to generate electricity for onboard demands and to power external devices.
The 5kW APU is mounted on the driver's side of the truck. An onboard power management system delivers electricity to the truck's systems or exports it off the vehicle as standard household power. The current APU is fueled with a mixture of methanol and water, and further development will enable it to use ultra-low sulfur commercial diesel fuel.
On the average, heavy trucks idle 20-40% of the time, using one to two gallons of fuel an hour. A single idling vehicle can easily consume more than 2,000 gallons of fuel in a year. The fuel cell APU is expected to reduce that usage, while reducing emissions and noise.
"The Army continues to take a leadership role in advancing fuel cell technologies," said Dennis Wend, executive director, Tank-Automotive and Armaments Command's National Automotive Center (NAC). "With our partners, Freightliner, Ballard and the University of Alabama, we have developed a fuel cell APU that shows an alternative for powering auxiliary devices on a parked heavy-duty truck instead of idling the engine.
"This technology has great potential benefits to the military and commercial fields by increasing comfort and efficiency of heavy-duty trucks while reducing their environmental impact," continued Wend.
The fuel cell APU designed for heavy vehicle application addresses the military need for additional power to support new digital communications (computers, satellite dishes, GPS and 3-D mapping systems).
Quiet, efficient fuel cell APUs improve overall fuel economy by allowing military vehicles to avoid engine idling during extended stand-by periods that occur near the battlefield.
Much of the Army's present logistic support system exists to move fuel, and any reduction in fuel consumption will have a positive impact.
Reliable, efficient and quiet APUs may make the first major automotive application of fuel cells feasible, due to their potential for significant environmental and economic benefits and relative affordability.
The Army will spend $10 million this fiscal year on fuel cell research, development and testing. This important dual-use technology has near-term and future benefits to the military.