Next-Generation Vehicle Options

The auto industry and the federal government are pursuing research and development of advanced vehicle and fuel technologies that could minimize the energy and environmental effects of the automobile, while retaining the personal mobility society has come to expect. Fuel cells, spark-ignition direct-injection (SIDI) engines, and compression-ignition direct-injection (CIDI) diesel engines for conventional and hybrid electric vehicles (HEVs) are promising options. Experts have different opinions on the potential for fuel cells to penetrate the internal combustion engine (ICE) market, as well as different opinions on the appropriate fuel. While fuel cells still offer the best long-term potential for high efficiency and low emissions, the ICE is a moving target; improvements are constantly being implemented. Fuel cell vehicles (FCVs) may have a hard time competing in the market, and radical redesign of conventional vehicles can deliver substantial near-term energy, environmental, and economic benefits.

Highly Fuel Efficient Car Developed by The Rocky Mountain Institute

Argonne undertook a scoping study that compares total fuel-cycle options for providing power to personal vehicles. Key differences among vehicle and fuel options were highlighted to identify critical research areas. The key question was, "How much of the energy from the fuel feedstock is available for motive power?" Greenhouse gases (GHGs) were assessed over the total fuel cycle. We also assessed emissions impacts.

Results

Total-fuel-cycle efficiency and carbon dioxide emissions, from raw resource extraction to final use, for selected vehicles are shown below. Fuel cell vehicles using hydrogen (from natural gas) and gasoline, and vehicles equipped with gasoline- and diesel-fueled ICEs were considered. The "high-performance" ICE vehicles are HEVs, while the "high-performance" FCVs use projected efficiencies from a fuel cell model. The reference case for FCVs assumes mid-term technology goals. Conventional vehicles are indicated by the reference case gasoline ICE and diesel ICE. Our analysis shows that an advanced gasoline or diesel HEV can be as efficient as an FCV based on mid-term technology. Differences, if any, will become apparent only after FCVs and advanced ICE vehicles are ready for market testing. For policy decisions, low emissions of criteria pollutants from FCVs and their less-certain GHG and fuel economy benefits (relative to advanced diesel HEVs) must be weighed against their earlier state of development. Similarly, unless fuel processing, combustion, and aftertreatment technologies are much improved, the fuel economy and GHG emissions benefits of advanced ICEs may not be realized as a consequence of new, much tighter emissions standards for nitrogen oxides and particulates.

Fuel Efficiency

CO2 Emissions

Future Plans

Future plans involve dissemination of results in various meetings, incorporating parts of the analysis into traditional models such as Argonne's GREET model, and expanding this analysis to include medium- and heavy-duty trucks.