Feasibility of a Regenerative Braking System for a School Bus
Gabrielle String 1, and Kenneth Visser†
Department of Mechanical and Aeronautical Engineering
A regenerative braking system (RBS) is proposed to improve the fuel efficiency of a school bus
and reduce the exposure of children to diesel particulates. The primary benefit of a RBS is a
decrease in the amount of fuel used to drive the bus, however an additional advantage could also
be a reduction in the exposure of school children to diesel emissions. A RBS captures and stores
the energy, typically lost to heat through friction during braking, and then uses this stored energy
to accelerate the vehicle forward. It has been determined that the most efficient RBS for large
vehicles is one that uses hydraulic fluid and a mechanical device to store the energy. The
ADvanced VehIcle SimulatOR (ADVISOR) from the National Renewable Energy Labs is being
used to model the drive cycles of the school bus. Previous studies from an EPA partnership with
the Eaton Power Corporation have shown up to a 65% fuel savings. Data on braking and
acceleration energies from ADVISOR and information from the Potsdam School District is being
used to design a hydraulic RBS and a prototype system will be developed and tested in the lab.
Figure 1: Parallel Hydraulic RBS
*
†
Class of 2011, Mechanical and Aeronautical Engineering Student, Clarkson University Honors Program
Associate Professor, Department of Mechanical and Aeronautical Engineering, Clarkson University