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Hybridization: Cost and Efficiency Comparisons for PEM Fuel Cell Vehicles
Technical Paper
2000-01-3078
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
This paper primarily compares costs and fuel economies of load following direct-hydrogen fuel cell vehicles with battery hybrid variations of the same vehicle. Additional information is included regarding load-following indirect methanol fuel cell vehicles. The key points addressed are as follows: the tradeoff between fuel cell system efficiency and regenerative braking ability; transient effects; and component cost differences. The difference in energy use and costs can vary significantly depending on the assumptions and the hybrid configurations. The mass of the battery pack creates the largest impact in energy use, while system efficiency losses roughly balance out with regenerative braking. For the direct-hydrogen fuel cell system, transient effects are small. These effects are expected to be significant for steam reformer/indirect-methanol systems (analyzed only graphically herein). Cost values are very sensitive to uncertainties, but tend to show similar results to those for energy use: vehicles with larger battery packs and smaller fuel cell systems tend to cost more. A key variable is battery replacement over the life of the vehicle. More frequent replacement required for certain battery technologies evens out the cost differential in comparison to the more expensive but longer lasting battery choices for the hybrids.
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Authors
- David J. Friedman - Fuel Cell Vehicle Modeling Program, University of California, Davis
- Timothy Lipman - Fuel Cell Vehicle Modeling Program, University of California, Davis
- Anthony Eggert - Fuel Cell Vehicle Modeling Program, University of California, Davis
- Sitaram Ramaswamy - Fuel Cell Vehicle Modeling Program, University of California, Davis
- Kar-Heinz Hauer - Fuel Cell Vehicle Modeling Program, University of California, Davis
Topic
Citation
Friedman, D., Lipman, T., Eggert, A., Ramaswamy, S. et al., "Hybridization: Cost and Efficiency Comparisons for PEM Fuel Cell Vehicles," SAE Technical Paper 2000-01-3078, 2000, https://doi.org/10.4271/2000-01-3078.Also In
References
- Friedman D.J., “Maximizing Direct-Hydrogen PEM Fuel Cell Vehicle Efficiency - Is Hybridization Necessary?”, Society of Automotive Engineers, PA, SAE 1999-01-0530 (or SP-1425), 1999.
- Burke A.F., “Hybrid/Electric Vehicle Design Options and Evaluations”, Society of Automotive Engineers, PA, SAE 920447, 1992; and Burke A.F., “On-Off Engine Operation for Hybrid/Electric Vehicle”, Society of Automotive Engineers, PA, SAE 930042, 1993.
- The exact point where the efficiency curve begins to roll-over has uncertainty associated with it. If auxiliaries represent a greater load, this roll-over will begin at a higher level of normalized power and would show a small improvement in the final results for hybridization.
- The transient behavior herein is primarily determined by the steam reformation based fuel processor model developed by Dr. Ramaswamy and the vehicle control systems developed by Karl Hauer.
- Johnston B., Friedman D., Burch K., Frazer C., Kilmer D., Scheiblich T., Funston D., Chattot E., McGoldrick T., Carlson R., “The Design and Development of the University of California, Davis FutureCar”, 1996 Future Car Challenge, Society of Automotive Engineers, PA, SAE SP-1234, 1997.
- Ford Motor Company, Direct-Hydrogen-Fueled Proton-Exchange-Membrane Fuel Cell System for Transportation Applications, July 1997, DOE/CE/50389-503.
- Springer T. E., Wilson M. S., Gottesfeld S., J. Electrochem. Soc., 140, 3513 (1993).
- Springer T. E., Zawodzinski T.A., Wilson M. S., Gottesfeld S., J. Electrochem. Soc., 143, 587 (1996).
- Friedman D.J. and Moore R.M., PEM Fuel Cell System Optimization, Proceedings of the Second International Symposium on Proton Conducting Membrane Fuel Cells, The Electrochemical Society, Inc., Pennington, NJ (1998).
- Moore R.M., Friedman D.J., Burke A.F., in Proceedings of Commercializing FCVs '97, Frankfurt, Germany, October 20-22, 1997.
- Lomax F.D., James B.D., Baum G.N., Thomas C.E., Detailed Manufacturing Cost Estimates for Polymer Electrolyte Membrane (PEM) Fuel Cells for Light Duty Vehicles, Directed Technologies, Inc., Arlington, October (1997).
- U.S. Department of Energy, Fuel Cells for Transportation 98: Annual Contractor's Report, Office of Advanced Automotive Technologies, Washington, D.C., November (1998).
- Lipman T.E., The Cost of Manufacturing Electric Vehicle Batteries, Report for California Air Resources Board, UCD-ITS-RR-99-5, Institute of Transportation Studies, Davis, May (1999).
- One driving cycle has been added to these results, the WFTP. This stands for the weighted federal test procedure. While showing the FUDS and US06 cycles provides some insight into the tradeoffs, neither one represents a “prototypical” urban drive cycle (assuming one even could exist). The WFTP is EPA's method of combining the newly introduced US06 with the standard FUDS cycle to represent general urban driving behavior. It is based on 78% FUDS and 28% US06 (40CFR86.164-00). It is interesting to compare the results for this weighted cycle with the results for the 1.25 FUDS cycle. While there are differences, they are not drastic and the overall pattern of results is quite similar.