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U.S. Department of Energy
Office of Scientific and Technical Information

Utilization of flywheel-hybrid drive trains for commercial taxicab vehicles

Technical Report ·
OSTI ID:5891002
Hybrid drive trains incorporating flywheel energy storage have been proposed as a means of improving vehicle efficiencies. In this application flywheels can recover braking energy ad increase engine operating efficiencies. Developments are required before flywheels can be effectively incorporated into improved drive trains. The economic and technical criteria necessary for flywheel hybrid drive trains to compete with alternative vehicle technologies are the most important factors in determining development requirements. This report quantifies the economic criteria, technical requirements, and conservation potential of flywheel-hybrid drive train, utilized in taxicabs operated in commercial fleets. The development requirements for this application are identified in light of these factors. Use of hybrid drive trains in urban taxicabs was shown to make substantial fuel efficiency gains possible. For the vehicle used in this study, the projected gains are from an existing 10.5 mpg to a maximum of 32 mpg. Nationwide, taxicab fuel consumption is substantial at 1.4 billion gallons annually. In addition, taxicabs represent an entry point to general automotive applications where 79 billion gallons of fuel are consumed annually. Relatively modest development efforts would lead to systems with substantially improved fuel efficiency. The most critical development requirements for this application are continuously variable transmissions, their controls, and high performance bearings.
Research Organization:
Draper (Charles Stark) Lab., Inc., Cambridge, MA (USA)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5891002
Report Number(s):
UCRL-15395; ON: DE82001670
Country of Publication:
United States
Language:
English