Life Cycle and Economic Analysis of Heavy Duty Diesel Vehicle Idling Alternatives

Abstract

Heavy Duty Diesel Truck (HDDT) divers are required by law to rest 8 hours for every 10 driving hours. As a consequence, the trucks are idled for long periods of time to heat or cool the cabin, to keep the engine warm, to run electrical appliances, and to refrigerate or heat truck cargo. This idling results in gaseous and particulate emissions, wasted fuel and is costly. Various technologies can be used to replace truck idling, including heaters, auxiliary power units, parking space electrification, and heating and air conditioning units in the parking space. In this paper the results of a life cycle analysis are reported giving the associated emissions savings and ecological burdens of these four technologies compared to truck idling. In this analysis the savings related to reduced engine maintenance and increased engine life are included. The fuel consumed and emissions produced by a truck engine at idle was obtained from experiments performed at Aberdeen Test Center (ATC). These idle emissions were compared to the pony pack auxiliary power unit (APU), the Espar direct-fired heater (DFH), Truck Stop Electrification (TSE), and Advanced Truckstop Electrification (ATSE). Of the four evaluated technologies, the Truckstop Electrification showed the most benefits to the truck drivers and the state. At a current average fuel price of $1.50 per gallon, the results show that truck stop electrification is most economical for the purposes of this study. Truck Stop Electrification results in a payback period of 1.53 for the driver, and 1.16 for the rest area, at the current price of diesel fuel. Advanced Truck Stop Electrification has a payback period of 0.83 years for the driver and a payback period of 3.66 for the rest area, based on a fee of $1.25 per hour. The rest area could reduce the payback by charging a higher fee, which would result in a greater payback for the driver. In addition, truck stop electrification showed the most emissions savings and the least ecological burdens. The APU and DFH showed considerable emissions reduction but were less economical, showing approximately 5 kg and 4 kg emissions savings per dollar, respectively.