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Line-haul truck engines are frequently idled to power hotel loads (i.e. heating, air conditioning, and lighting) during rest periods. Comfortable cabin climate conditions are required in order for mandatory driver rests periods to effectively enhance safety; however, the main diesel engine is an inefficient source of power for this conditioning. During idle, the diesel engine operates at less than 10% efficiency, consuming excess diesel fuel, generating emissions, and accelerating engine wear. One promising alternative is the use of small auxiliary power units (APUs), particularly fuel cell-based APUs. The Institute of Transportation Studies (ITS-Davis) developed an ADVanced VehIcle SimulatOR (ADVISOR)-based model to quantify the costs and benefits of truck fuel cell APUs. Differences in accessories, power electronics, and control strategy between the conventional engine idling and APUequipped systems are analyzed and incorporated into the model.

California Air Resources Board's transit bus fleet regulation required public transit fleets in California to reduce emissions starting in 2002 [1]. In response to this rule, San Francisco Municipal Railway (Muni) launched the “Alternative Fuel Pilot Project”. The objective of the project is to compare the on-road performance, emissions, maintainability, safety, and costs of advanced diesel and alternative fuel buses over a two-year period. This paper discusses the preliminary emissions results from chassis dynamometer testing conducted during the first six months of the emissions study. The California Truck Testing Service's dynamometer facility tested four types of buses: conventional diesel, conventional diesel with particulate traps, compressed natural gas, and hybrid-electric transit buses.

A principal motivation for introducing alternative fuels is to reduce air pollution and greenhouse gas emissions. A comprehensive evaluation of the reductions must include all Life Cycle activities from the vehicle operation to the feedstock extraction. This paper focuses on the fuel upstream activities only. We compare the results and methods of the three most comprehensive existing fuel upstream models in the U.S.A. and we explore the differences and uncertainties of these types of analyses. To explicitly include the impact of uncertainties, we create a new model using the following approaches: Instead of using a single value as input, the new model deals with ranges around the most probable value. Ranges are discussed and calibrated by an expert network, in terms of their relative probability. Probabilistic function techniques are applied to study the impact of the uncertainties on the model output.

Although various legislation and regulations have been adopted to promote the use of alternative-fuel vehicles for curbing urban air pollution problems, there is a lack of systematic comparisons of emission control cost-effectiveness among various alternative-fuel vehicle types. In this paper, life-cycle emission reductions and life-cycle costs were estimated for passenger cars fueled with methanol, ethanol, liquified petroleum gas, compressed natural gas, and electricity. Vehicle emission estimates included both exhaust and evaporative emissions for air pollutants of hydrocarbon, carbon monoxide. nitrogen oxides, and air-toxic pollutants of benzene, formaldehyde, 1,3-butadiene, and acetaldehyde. Vehicle life-cycle cost estimates accounted for vehicle purchase prices, vehicle life, fuel costs, and vehicle maintenance costs.

This paper is a comprehensive comparative analysis of methanol, compressed natural gas, and liquefied natural gas as automotive fuels. First, we examine natural gas, coal, and biomass feedstocks, and the “security” of foreign feedstocks. Next, vehicle performance and emissions are considered, followed by an analysis of vehicle refuelling and storage technology. Environmental impacts of fuel production and distribution are analyzed; followed by a review of health, flammability, transport, and end-use hazards. We perform a detailed cost analysis that combines fuel cost and vehicle cost into discounted life-cycle cost-per-mile. Finally, we discuss the feasibility and implications of transitions to methanol and natural gas from our current vehicular fuel system. We find that natural gas vehicles may offer slight economic and environmental advantages, but that a transition to natural gas fuel would be more difficult, at least in the U.S.

A survey of diesel car and light truck owners was conducted in California to determine the importance of limited fuel availability in a household's vehicle purchase decision. Behavioral, attitudinal, and perceptual differences toward limited fuel availability are reported. In particular, the importance of fuel availability is examined as a function of the number of diesel fuel stations. Results are generalized to other non-gasoline vehicles.