Fuel Cell Bus
Operates with a fuel cell that uses hydrogen as fuel.
How a Ballard® Fuel Cell Works
1. Expanded single fuel cell
Each individual fuel cell consists of a ﬂow
ﬁeld plate on either side of a membrane
electrode assembly (MEA).
2. Membrane electrode assembly
The MEA consists of a proton exchange
membrane (PEM) sandwiched between two
paper-thin carbon ﬁber-based gas diffusion
electrodes (anode and cathode). In between
the electrodes and the membrane is a very
thin layer of catalyst, made of platinum.
3. Flow ﬁeld plates
Hydrogen fuel (H2) passes through channels
in a ﬂow ﬁeld plate, distributing hydrogen
evenly across the gas diffusion layer of
the anode, where it comes in contact
with the platinum catalyst that drives the
electrochemical reaction. Meanwhile,
oxygen (O2) from the air passes through
channels in the opposite ﬂow ﬁeld plate on
the cathode side.
4. Hydrogen gas ﬂow 5. Air ﬂow
In the presence of the platinum catalyst on the In the presence of the catalyst on the cathode,
anode, hydrogen gas molecules separate into two oxygen from the air combines with the hydrogen
protons and two electrons each. The protons migrate protons that migrated through the PEM and
through the PEM from the anode to the cathode. The combines with the electrons from the anode via
electrons, which cannot pass through the PEM, are the external circuit to form water vapor (H2O)
conducted through the external circuit in the form and heat, which are the only by-products of the
of electricity before arriving at the cathode. electrochemical process.
ZERO EMISSION FUEL CELL BUS
Frequently Asked Questions Zero-Emission Bus
The Santa Clara Valley Transportation
What is the lifetime of a fuel cell product?
Authority (VTA) and San Mateo County
A Ballard fuel cell lifetime depends Transit District (SamTrans) operate three
on the power requirements of each 40-foot, low-ﬂoor, hydrogen fuel cell buses
product. For example, residential as part of the Zero-Emission Bus (ZEB)
cogeneration fuel cells have reached Program. VTA is the lead agency in the
over 10,000 hours in demonstration operation of these buses and SamTrans
shares in the capital and operating costs.
ﬁeld trials, whereas vehicular fuel
The test program consists of facility
cells used in demanding start, stop, modiﬁcations and installation of a
and accelerate drive cycles have hydrogen fueling station at VTA’s Cerone
a lifetime of approximately 2,500 Operations Division, as well as training for
hours. Ballard continues to work hard VTA and SamTrans personnel on the new
to improve fuel cell durability through technology.
research and development, and Ballard® fuel cell
demonstration programs such as the VTA fuel cell buses. For more information about the ZEB
What is the difference between a fuel cell and a battery? Santa Clara Valley Transportation Authority
Batteries are considered a power “storage” device as they store their fuel. 3331 North First Street, Bldg B
Thus, when a battery’s fuel is spent, the battery must be disposed of or San Jose, CA 95134
recharged. In contrast, fuel cells are a power “generating” device as they
draw fuel from an external source – such as a hydrogen cylinder – and Phone: (408) 321-7575
generate electricity for as long as fuel is supplied. TDD: (408) 321-2330
Fax: (408) 321-7576
How is a fuel cell engine different from an internal
Fuel cell engines produce
electricity without combustion Ballard Power Systems
and with little, if any, noise, Power to Change the World® is the vision
vibration, air pollution or of Ballard Power Systems, the recognized
greenhouse gas production – as world leader in the design, development
opposed to internal combustion and manufacture of zero-emission proton
engines, which “burn” their exchange membrane fuel cells. Ballard’s
mission is to develop fuel cell power as a
fuel. Fuel cell engines are also
practical alternative to internal combustion
two to three times as efﬁcient engines through technology leadership.
as combustion engines, so they Zero-emission bus with open panels showing the
use fuel more efﬁciently. motor at the rear and the fuel cell on the side. For more information about Ballard
Did Ballard invent fuel cells? Ballard Power Systems, Inc.
Sir William Grove, a Welsh physicist and patent attorney, ﬁrst developed
4343 North Fraser Way
the fuel cell in 1839. Then, in the 1960s, NASA used fuel cells to generate
Burnaby BC, Canada V5J5J9
electricity for space missions. In 1983, Ballard began development of a
Proton Exchange Membrane (PEM) fuel cell, and today is recognized Phone: (604) 454-0900
as the world leader in the design, development and manufacture of zero- Fax: (604) 412-4700
emission PEM fuel cells. Email: email@example.com