WASHINGTON, D.C. – Freightliner LLC has unveiled a heavy-duty concept truck that uses fuel cells to generate electrical power for on-board vehicle appliances.

The demonstration truck – a Class 8 Century Class S/T – was displayed at the Department of Transportation’s National Intelligent Vehicle Initiative meeting in Washington, D.C. The truck utilizes a fuel cell auxiliary power unit that generates electricity for everything from cab heaters and air conditioners to on-board computers, televisions, stereos, refrigerators and coffee pots.

The alternative power system includes two Ballard fuel cell “stacks” operating in series as an auxiliary power unit (APU). The proton exchange membrane (PEM) fuel cells are fed with hydrogen from a 52-US gallon tank on the left side of the truck along the frame rails. Within the fuel cell, hydrogen is split into positively charged protons and negatively charged electrons. The protons can pass through the membrane, but the electrons cannot, so a voltage builds up in the fuel cell. The only by-product of this process is pure water.

The fuel cell APU produces more than 1.4 kilowatts, 120 volts AC or 12 volts DC power. Meanwhile, the APU is connected to the vehicle’s electrical system through an 1800-watt inverter, which takes electricity from the fuel cells, batteries and alternator, and provides power to vehicle accessories/batteries in the required form. n