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Applications
for fuel cells
It’s all very well saying we can produce clean electrical power with only heat and water vapour as emissions but can we
apply the technology economically? More importantly, will
the environmental costs of producing fuel cells and their fuel
actually be higher than the environmental gains made by
using the technology?
30 Silicon Chip
monetary costs for them. There is little
doubt that the same conclusion will
apply to the use of fuel cells.
applications, particularly in space.
When aircraft manufacturer Pratt &
Whitney won the contract to supply
fuel cells for the Apollo program in
the early 1960s, their fuel cell design
was based on modifications to the
Bacon patents for alkaline fuel cells,
which are the most efficient at low
temperature.
Three units capable of producing 1.5kW, or up to 2.2kW for short
periods, were operated in parallel.
Weighing around 114kg per unit and
fuelled with cryogenic hydrogen and
oxygen, these units ran for 10,000
hours during 18 missions without an
in-flight incident.
And they produced all the fresh
Part 3 in our series
on Fuel Cells
by
GERRY NOLAN
Now let’s look at some of the applications of fuel cell technology.
Developments have gone well beyond the prototype stage for several
CO2 Emission
NOX Emission
Noise (dB)
100
1~2
~0
0
~0
~0
0
Fuel Cell
<100
Petrol Engine
<42
65
Diesel Engine
Fuel Cell
Gas Turbine
0
Petrol Engine
0
Diesel Engine
200
100
100~
110 110 90~
100
Gas Turbine
400
50
200
Fuel Cell
600
250
Gas Turbine
100
800
300
Petrol Engine
150
1000
400
Diesel Engine
200
SOx Concentration (ppm)
250
Fuel Cell
230
Noise
200
1400
1200
Petrol Engine
290
Diesel Engine
310
300
Gas Turbine
350
350
SOX Emission
500
1600
NOx Concentration (ppm)
400
CO2 Emission ton-C/year
I
f hydrogen becomes the fuel of
choice, what are the costs of manufacturing it and installing a completely new fuel distribution system?
Experience has shown that we
should ask these questions early in the
development of any new technology,
no matter how great it looks at first
glance. Looking at comparisons with
existing fuel systems, the hydrogen
fuel cell certainly comes out ahead
environmentally.
Fig.1 shows clearly that hydrogen
fuel cell technology is below diesel,
gas turbine and petrol engines with
regard to CO2, NOX, SOX and noise
emissions.
Fig.2 shows a comparison between
the overall environmental costs for
existing internal combustion engine
technology (ICE), electric vehicle
technology (EV) and hydrogen fuel
cell technology (H2FC).
When all costs are considered: new
technology costs, on-going upstream
costs (eg, fuel production and distribution) and emission costs, particularly
for vehicular applications, fuel cell
technology is ahead but it is not a
clear-cut conclusion.
In his article on solar power in the
March 2002 issue of SILICON CHIP,
Ross Tester concluded that most
people would not use solar cell technology, no matter how environmentally desirable, unless it meant lower
Fig.1: comparision of carbon dioxode, nitrous oxides, sulphur dioxide and noise
emissions between the four main engine types. As you can see, fuel cells win on
every measure.
www.siliconchip.com.au
An installation of five PC 25TM fuel cells at Anchorage
in Alaska. Courtesy of International Fuel Cells LLC
water for the space missions as well!
Continuing development by International Fuel Cells (which is a
division of UTC, the company that
P&W became) has meant that the fuel
cell stacks used on each shuttle can
now provide around ten times the
power of similar-size units used in
the Apollo craft.
Fuelled by cryogenic hydrogen and
oxygen the cells are 70% efficient
and have now completed over 80,000
operating hours in more than 100
missions. And there are no backup
batteries.
Following the space program success, fuel cells have been used in:
• Stationary power installations
for utilities, factories, emergency
power for hospitals, communications
facilities, credit card centres, police
stations, banks and computer installations
• Diverse military applications
• Domestic power supplies for individual residences
• Mobile phones, laptop computers and other personal electronic
devices
• Transportation – particularly cars
and buses but also in boats, trains,
planes, scooters and bicycles, as well
as highway road signs
• Portable power for building sites,
camping and vending machines.
• Landfills and waste water treat-
100
80
60
Emissions
40
20
0
Ongoing upstream costs
ICE
EV
H2FC
New technology costs
Fig.2: the environmental costs of new technology versus old for internal combustion engines, electric vehicles and hydrogen fuel cells. Small wonder that
fuel cells are regarded as the “green” alternative!
www.siliconchip.com.au
ment plants (which are using fuel
cells to convert the methane gas they
produce into electricity).
Energy supply systems based
on fuel cells
Regardless of the type of fuel cell
used, they all require a variety of
peripheral units to store or convert
fuel and convert the DC power generated for AC applications. In addition,
they need pumps for fuel and air and
ventilation fans to remove heat and
water vapour.
Fig.3 represents a generic system
based on fuel cells which could be a
large utility energy system, a portable
power supply or the power pack for a
mobile phone – which may not need
AC but will still need power conditioning.
Now we’ll take a closer look at the
way fuel cells fit into each of these
various energy system applications.
Stationary systems
These fall roughly into the three
categories: grid-connected; back-up
power supplies and domestic installations.
At the time of writing, more than 200
fuel cell systems have been installed
all over the world in hospitals, nursing homes, hotels, office buildings,
schools and airport terminals. They are
either being used to provide primary
July 2002 31
at
He ery
v
co
re
Air
Fue
l
Air
H
2
Fue
pro l
ces
sor
Fig.3: for those who might have
missed our in-depth explanation earlier in this series, this graphic shows
the operation of a typical fuel cell
n
ea
system. Oxygen (from the air)
Cl ust
and hydrogen (from a hydrocarbon
ha
x
e
fuel) enter at left. Pure hydrogen is
extracted by the processor. Both combine in the fuel cell(s) to form water,
with a “byproduct” being
a flow of electrons – or
a DC current.
This is then
used, stored
(eg, by
charging a
battery), or
DC
inverted
to AC.
Fue
sta l cel
ck l
Fuel Cell System
power or as a backup supply.
The following examples are typical
of stationary installations that have
been announced in the last year:
• In September 2001, the town of
Woking, 40km southwest of London,
became the first community to sign up
for a commercial fuel cell installation
in the United Kingdom.
They contracted with UTC Fuel
Cells for a 200kW PC25TM system
to provide electricity and heat for
the pool in Woking Park recreational
centre, as well as electricity to light
the park.
• In December 2001, UTC Fuel Cells
announced that a PC25TM fuel cell
AC
pow
e
r
Pow
con er
dit
ion
er
power plant had been installed at Ford
Motor Company’s North American
Premier Automotive Group headquarters in California. The 200kW plant
provides 25% of the building’s power
as well as hot water for the facility.
• Siemens Power Generation Group
will build a solid oxide fuel cell
(SOFC) power plant with a maximum
electrical capacity of 250kW in Hanover, Germany, to be completed by 2003.
• The world’s first fuel cell/gas
turbine hybrid power plant is now
operating at the National Fuel Cell
Research Center in Irvine, California. The system features a Siemens
Westing-house solid oxide fuel cell
combined with an Ingersol Rand microturbine to produce approximately
190kW of electricity. Early test data
show electrical efficiencies of approximately 53%, believed to be a world
record for the operation of any fuel
cell system on natural gas.
Improvements in the technology
could ultimately raise efficiencies to
60% for smaller systems and 70% or
higher for larger systems.
Residential installations
Although mass production will be
crucial to bring prices down to make
domestic installations practical, with
large companies such as International
Fuel Cells, Ballard Power and Avista
Labs becoming involved, this will
eventually happen.
From fuel processor . . .
Most domestic systems have a fuel
processor as part of the fuel cell installation. This includes a fuel reformer,
which processes a hydrocarbon fuel
such as natural gas, into a hydrogen-rich gas known as reformate. A
carbon monoxide (CO) cleanup unit is
necessary to reduce the high concentrations of carbon monoxide produced
in the process to acceptable levels
(under 50ppm).
At the heart of the fuel cell system
is the PEM fuel cell stack, which is
made up of a membrane electrode assembly sandwiched between two gas
diffusion layers with bipolar plates
on each side.
The reformate (hydrogen) from the
CO cleanup system feeds the fuel
side of the fuel cell and the PEM cell
generates a DC potential as described
last month.
This is fed to the power conditioner
which converts the low-voltage DC to
When we think “fuel cells”, until now we’ve automatically tended to think “big”: space shuttles, buses, cars and
stationary power generation. But as these pictures show, fuel cells can be downright miniscule! The two pictures at
left show just how small fuel cells can be made (yes, that is a pencil!). The third photo, courtesy RoamPower, shows a
fuel cell-powered emergency torch, while the fuel cell-powered notebook computer at right (courtesy Ballard Power
Systems) is a portent of commercial products planned for release as early as next year and the year after.
32 Silicon Chip
www.siliconchip.com.au
One of the main areas of devel-
Hydrogen
Tanks
Fuel Cell Supply Unit
opment of fuel cells in transportation is in public transport buses. In
the first article in this series, we
showed the outside of the Citaro
fuel cell powered bus. Now we
can show you the X-ray version
so that you can see where all the
pieces fit in.
Note the hydrogen supply tanks
mounted in the roof. This not only
protects them from damage in case of a
collision, especially, the hydrogen tanks, but
allows for a continuous low floor design.
Hydrogen is very flammable if not handled correctly.
Its safety is a factor that people will need to be convinced of
before rushing out to buy a fuel cell powered car. In view of
this, Honda has run front and rear collision tests on its FCX-V5
prototype, at a speed of 55km/h. The results confirmed high
passenger protection safety during frontal tests and there was
no hydrogen leakage from the high-pressure tank.
high-voltage AC. Batteries are usually
used to ensure that the system copes
with power surges from motor startups or when peak demand exceeds
the system output.
Fuel cell systems, generally with
very quick start-up featured, seem to
be ideal for primary household supply
and as back-up for peak or emergency
use or for remote areas.
A very attractive feature is that
‘waste’ heat can be used to provide
hot water or space heating in a home.
Fuel Cells
Air
Conditioner
Transmission
Since fuel cells operate silently, they
are highly preferable to the typical
diesel generator on rural properties.
Many of the prototypes being tried
in residences use hydrogen extracted
from propane or natural gas.
Transportation
As noted in the first article in this
series, much of the development work
being carried out with fuel cells is in
the transportation industry. More than
100,000 fuel cell powered vehicles are
Electric Motor
Auxiliary
Components
expected on the world’s roads by 2004.
As with the stationary fuel cell
installations, peripherals are again
required.
Fig.3 is a schematic of the main components. With wheel-mounted electric
motors, fuel cell technology allows
great flexibility in the placement of
the various components.
All of the major automotive manufacturers now have at least one fuel cell
vehicle under development, including
Honda, Toyota, Daimler-Chrysler, GM,
Ford, Hyundai, Nissan, Volkswagen
and BMW.
Research has shown that the amount
of carbon dioxide produced from a
small car can be reduced by as much
as 72% when powered by a fuel cell
running on hydrogen reformed from
natural gas instead of a conventional
internal combustion engine.
However, it is not enough for the
technology to meet tighter legislation
on vehicle emissions. It must also pro-
Fuel cells on
(small) wheels:
the “MOJITO FC”
fuel cell powered
scooter showing
the fuel cell stack
in the pannier.
The hydrogen
supply is under
the pillion seat.
At right is the
fuel cell pack in a
Volkswagen car.
www.siliconchip.com.au
July 2002 33
Magazine’s 2001 “Inventions of the
Year” awards.
Portable fuel cell power
Fig.4: schematic diagram of the main components of a fuel cell system in a car
with electric motors driving the front wheels, or the rear wheels, independently.
vide transport that offers equivalent
convenience and flexibility.
Being able to reach operating temperature rapidly, provide competitive
fuel economy and give a responsive
performance are all considerations
that make the proton exchange membrane (PEM) fuel cells the favourite.
They reach operating temperature
(around 800°C) quickly and respond
rapidly to varying loads, as well as
offering efficiency of up to 60%, compared to the 25% (at best) achieved by
internal combustion engines.
PEM fuel cells also have the highest
power density, which is crucial in
modern vehicle design, and the solid
polymer electrolyte helps to minimise
potential corrosion and safety management problems.
However, to avoid catalyst poisoning at this low operating temperature
,PEM fuel cells do need an uncontaminated hydrogen fuel.
Still, most major vehicle manufacturers regard the PEM fuel cell as
the eventual successor to the internal
combustion engine.
The fuel cell system, including all
electronics, valves and fans, weighs
slightly less than 6kg, with the fuel
vessel weighing only 4.3kg.
Manhattan Scientifics believes fuel
cell scooters with optimised drive systems will achieve a higher top speed
and quicker acceleration than current
vehicles with 50cc and 80cc internal
combustion engines.
Manhattan Scientifics and Aprilia
previously developed the Aprilia ENJOY FC, a concept fuel cell powered
bicycle which received one of Time
In the not-too-distant-future, miniature fuel cells will enable people
to talk for up to a month on a mobile
phone without recharging the battery.
Miniature fuel cells will also power
laptops and Palm Pilots for many
hours longer than batteries can.
Direct methanol fuel cells powering
mobile phones have already been tested and the Casio Computer Company
intends to begin selling methanol fuel
cells from 2004.
These cells will be able to continuously power a laptop computer for as
long as 20 hours, compared with about
3-5 hours from batteries.
The methanol fuel for its fuel cells
is expected to cost about 30 cents per
litre, which sounds incredibly cheap
when you consider the size of the unit
that will be using it.
Landfill treatment
According to the US EPA’s Landfill
Methane Outreach Program, landfill
or biogas has already been tapped at
140 landfills in the USA to provide
methane gas through fuel processors
directly to fuel cells.
Since a demonstration test in 1992
at the Penrose Landfill, in Sun Valley,
California proved successful, fuel
Scooters & bicycles
Manhattan Scientifics and Aprilia
unveiled a fuel cell powered concept
scooter at the International Paris Fair
in April this year. Called “MOJITO
FC,” the scooter is powered by Manhattan Scientifics’ hydrogen fuelled
3kW fuel cell.
It is expected that production models will have a range of nearly 200km
and a top speed of at least 60km an
hour.
34 Silicon Chip
A Plug Power 7kW residential PEM domestic fuel cell installation. Plug Power
has been testing the above unit in a home since 1998. Detroit Edison co-founded
the company and General Electric agreed in 1999 to distribute and service
Plug Power cells. Such support has boosted expectations of a commercial introduction of the domestic fuel cell this year.
www.siliconchip.com.au
cells have been installed and are now
operating at landfills and waste water
treatment facilities in several states in
America as well as in Japan.
Groton Landfill in Connecticut,
which has been operating since 1996,
produces 600,000kWh of electricity a
year, with a continuous net fuel cell
output of 140kW. In 1997, ONSI (another division of UTC that markets fuel
cells) installed a system at the Yonkers
waste water treatment plant that produces over 1,600MWh of electricity
per year, while releasing only 30kg of
emissions into the environment.
The city of Portland, Oregon also
installed a fuel cell to produce power
using anaerobic digester gas from
a waste water facility. It expects to
generate 1,500MWh of electricity per
year, reducing the treatment plant’s
electricity bills considerably.
Toshiba has installed fuel cells that
run on waste gases at the Asahi and
Sapporo breweries and is also targeting local government to sell fuel cell
systems that run on gas from sewage,
as it has done in Yokohama City.
Military applications
Fuel cells could provide power for
www.siliconchip.com.au
most types of military equipment from
land and sea transportation to portable
handheld devices used in the field, so
military applications are expected to
become a significant market for fuel
cell technology. The efficiency, versatility, extended running time and quiet
operation make fuel cells extremely
well suited for military applications.
Clearly, fuel cells would have many
advantages over conventional batteries. For a start there would be no
need to worry about the logistics of
supplying spare batteries. In a similar
way, the efficiency of fuel cells for
transport would dramatically reduce
the amount of fuel required during
manoeuvres. Since the 1980s, the US
Navy has used fuel cells for deep marine exploration craft and unmanned
submarines.
How much do fuel cells cost?
Ah, the key question! As mentioned
at the start of this article, most people
won’t take up new technology unless
they feel that the tangible benefits
outweigh the monetary costs.
Fuel cell power plants have been
offered for about $6000 per kilowatt
installation cost but this would only
An Avista Labs
Independence 1000
– a 1kW
PEM fuel
cell.
be acceptable in areas where electricity prices are high and natural gas
prices low.
A study by Arthur D Little, Inc.
predicted that when fuel cell costs
drop below $3000 per kilowatt, they
will achieve much wider market penetration.
In cars, fuel cells will have to be
much cheaper to become commercialSC
ly acceptable.
July 2002 35
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