Foothill Transit Electric Bus Evaluation

NREL is evaluating the in-service performance of 12 fast-charge battery electric buses
compared to conventional compressed natural gas buses operated on similar routes by
Foothill Transit in West Covina, California.

Launched in 2015 in conjunction with a previously funded California Air Resources
Board research project, this study aims to improve understanding of the overall usage
and effectiveness of fast-charge electric buses and associated charging infrastructure
in transit operation.

Foothill Transit has fully electrified one route in its service area and is investigating
the feasibility of electrifying other routes as well. The electric buses under study
were Proterra EcoRide BE35 transit buses with eight 368V lithium-titanate battery
packs offering 88kWh of energy, which can be completely charged in less than 10 minutes
via two 500kW fast chargers located mid-way along the route.

The on-road portion of the evaluation focuses on collecting and analyzing vehicle
performance data from the electric buses and the conventional buses. Based on the
field data, NREL will develop a validated vehicle model using the Future Automotive Systems Technology Simulator, or FASTSim, to study the impact of route selection and other vehicle parameters.
NREL will also analyze the infrastructure requirements and grid-side impacts of the
high-power charging stations. In addition, NREL will conduct chassis dynamometer evaluation
of the vehicles to determine the fuel economy and emissions impact of the electric
bus technology in a controlled setting.

Initial results indicate that the electric buses offer significant fuel and emissions
savings compared to similar conventional vehicles. The final results will help Foothill
Transit determine other possible routes suitable for electrification and provide unbiased
technical information to other parties interested in adding such vehicles to their
fleets.

Publications

The following documents provide more information about the study.