Researchers at Penn State University’s
Pennsylvania Transportation Institute have spent the last few months testing an
all-electric version of the Proterra FCBE 35. This 35-foot bus was able to
achieve a diesel equivalent of 29 miles per gallon (MPG) in commuter settings,
21 MPG in downtown settings and 17 MPG in congested urban arteries. The
institute’s findings bode well for future implementation of the Proterra FCBE
35 in major cities worldwide.
The Pennsylvania Transportation Institute
simulated traffic conditions and traffic patterns for a central business
district, a congested arterial street and a commuter route. The central
business district route required seven stops per mile with a top speed of 20
miles per hour. The institute put the Proterra FCBE 35 through a less rigorous
commuter route with one stop per mile and a top speed of 40 MPH. Each
simulation featured the weight of 34 passengers and a single driver to recreate
the public transit experience.
The all-electric Proterra FCBE 35 features
a UQM PowerPhase 150 electric propulsion system as well as an Altairnano
lithium-ion battery. The UQM system can produce continual output of 134
horsepower to keep the bus moving through light flooding and snow piles. The Proterra
FCBE 35 is lighter than most public buses due to its composite plastic-metal
body, which decreases the weight carried by the electric drive system. The UQM PowerPhase
150 was built with regenerative braking, speed control and other features to
store electrical power for periods of consistent acceleration.
The simulated transit routes allowed Proterra
to test out its TerraVolt fast-charge system on an actual vehicle. The Proterra
TerraVolt allowed the FCBE 35 to recharge completely within 20 minutes, a
necessity for transit systems that need buses to get in and out as quickly as
possible. The Proterra TerraVolt was used to replenish the FCBE 35 at quarter
and half capacity to avoid the strain of running on low energy.
The biggest critique of the Proterra FCBE
35 simulations is that each run was completed without the strain of air
conditioning. The researchers conducting the simulated transit routes indicate
that air conditioning could reduce the diesel equivalent MPG by 30%. Even with
this limitation in mind, the Proterra FCBE 35 tests at Penn State University
are promising for advocates of clean public transportation. As the Proterra
FCBE 35 all-electric bus moves from the lab to the streets, we will see if it
can stand up to the day-to-day rigors of city transit systems.
