Piston engine, R.I.P.? Eco-friendly fuel cells may revolutionize the automobile
(U.S. News & World Report; 05/11/98)
Running the 66 Chicago Avenue route through downtown Chicago, the big,
new 39-passenger transit bus is silent like a ghost. No diesel engine roar
heralds its approach for waiting passengers. And when it pulls away from a
stop, no choking cloud of black exhaust smoke follows it down the street.
The only emission is a wisp of warm moist air that puffs from a silver
stack atop the vehicle.
The No. 66 bus may run quietly, but it is making a very loud statement: The
tried-and-true internal combustion engine may at last have a serious
competitor. The remarkable vehicle--one of three that began service on
Chicago's streets in March--is propelled by a fuel cell, an electric power
generating system similar to those on the space shuttle. It works by
electrochemically combining hydrogen, stored in tanks on the roof of the
bus, and oxygen from the air to produce electricity, heat, water vapor--and
no pollutants whatsoever. The process is precisely the reverse of the
familiar high school experiment in which an electric current is passed
through water to crack it into its constituent hydrogen and oxygen gases.
Equipping motor vehicles with clean, efficient, technically elegant fuel
cells is a dream that engineers have held for years. General Motors, for
example, has experimented with them for more than a decade. The cost,
however, was always too high-- roughly 100 times more expensive than a
standard gasoline engine. Now, the prospect that costs can be substantially
reduced, combined with growing pressure on car makers to reduce vehicular
pollution, has touched off a worldwide scramble in the auto industry--in
particular, Daimler-Benz, Ford, GM, and Toyota--to put fuel-cell vehicles
on the road. Their target date is 2004, barely an eye blink away for auto
manufacturers who must plan their products years in advance. Chrysler
engineers are also enthusiastic about the technology, but they believe a
more realistic date to see fuel-cell cars in dealer showrooms is 2010.
Eco-cruisers. Fuel cells face several formidable challenges, ranging from
lingering technical and production problems to today's supercheap gasoline
prices. Americans have been snapping up heavyweight, gas-guzzling sport
utility vehicles, a trend that suggests U.S. consumers may be reluctant to
spend more for cars that do less damage to the environment. Even so,
ruthlessly pragmatic auto executives who scoff at other alternative power
systems concede that fuel-cell power plants have the potential, at least,
to replace their beloved piston engines--and do so sooner than just about
anyone thought possible a few years ago. GM Vice Chairman Harry Pearce
calls fuel cells the best long-term solution because they "are very high in
efficiency and potentially very low in emissions." Ford's chairman, Alex
Trotman, told stockholders in the company's latest annual report that "we
view fuel cells as one of the most important technologies for the early
21st century."
The key player in the race, however, is neither an auto maker nor a Fortune
500 corporation. It's tiny Ballard Power Systems Inc., located in Burnaby,
British Columbia, a company with 400 employees and barely $25 million in
annual revenues. Yet, as the acknowledged leader in fuel cells, Ballard has
seen its stock soar from $8 a share in 1993 to $115 last week; its
price/earnings ratio (the price of a share of stock divided by earnings per
share for a 12-month period) is a stunning 1,477, compared with the
Standard & Poor's average of 27.
Ballard also has some very high-powered new friends. In a series of deals
worth $650 million, Germany's Daimler-Benz, maker of Mercedes-Benz cars and
trucks, last August purchased 20 percent of Ballard. Since the only way to
cut the cost of manufacturing fuel cells is to produce a large number of
them, Daimler-Benz wanted to team up with another big global car maker.
Then Ford bought 15 percent of Ballard in December. The three companies
will work together to commercialize the technology. Ballard will develop
the fuel cells, Ford will make the electric drive motors and electronic
controllers, and Daimler-Benz will assemble the crucial accessories--like
fuel processors--to make the system work. "When auto companies want to put
their cars on the road in 2003," says Ballard CEO Firoz Rasul, "we want to
be in the position to be their supplier."
Ballard enjoys a commanding lead, at least for now, but other companies are
racing to develop the technology. Toyota, for example, is working on its
own fuel cells. "We're doing it all internally," says Mark Amstock,
alternative fuel vehicle planning manager for Toyota in the United States.
"It's too significant a market to leave to our competitors." GM has the
same view and expects to have a production-ready car, with its own fuel
cell, by 2004. "We're making a substantial investment, even by GM
standards," says Bryan McCormick, executive director of GM's fuel-cell
program. And International Fuel Cells, which is owned by United
Technologies Corp. and Toshiba and makes the units for the space shuttle,
is quickly setting up a new company dedicated to automotive fuel cells.
Green light. The Ballard/Daimler-Benz/Ford deal "served as clear evidence
that the technology was going to commercialize faster than we originally
thought," says Bill Hahn, IFC's vice president for business development. He
argues that the firm's cells will be simpler and smaller than Ballard's for
the same power output. A typical fuel cell for a small car will deliver
about 50 kilowatts. By comparison, the three fuel cells in the space
shuttle produce a total of only 15 kilowatts.
All the past work on battery-powered electric cars--GM alone claims it has
spent a half-billion dollars--may pay off for fuel-cell machines. They are
electric cars in which a fuel cell replaces the batteries, so range is
limited only by the size of the fuel tank. The electronic gear and electric
motors are the same.
The cost of fuel cells is expected to drop sharply once they are produced
in high volume. Bradford Bates, Ford's fuel-cell research manager, says
that if you take a fuel cell apart "and lay out all the pieces on the
floor, and you do the same for a gasoline engine, the gasoline engine has
more complex pieces made out of more expensive materials at higher
tolerances." Fuel- cell stacks today are made by hand. But Bates says that
the individual cells can be made by a machine similar to a printing press
and assembled robotically. "There are all kinds of challenges but no
fundamental problems," he says. Adding to the attractiveness, he says,
"fuel cells have no wear-out mechanism." No one, in fact, knows how long
one might last, but it's certainly much longer than a modern gasoline
engine.
The biggest problem has nothing to do with the cells themselves. It's where
to get the hydrogen fuel. The Chicago buses can run on compressed hydrogen
gas because they're big enough to carry large tanks and they are refueled
every night back at the barn. Cars, however, are too small to carry big
tanks of gaseous hydrogen. A more compact liquid fuel, such as methanol,
gasoline, or kerosene, is required. In order to strip the hydrogen from
these fuels, a kind of mini chemical factory, called a fuel processor or
reformer, will be needed on every vehicle. The challenge, says Ramon
Espino, director of the chemical sciences laboratory for Exxon Research and
Engineering Co., "is to take the chemistry we know very well how to do and
do it in a little gadget that fits under the hood of a car."
There are two "killer variables" to deal with, says Espino, who is working
under contract to GM. The first is how quickly the reformer can be started.
The most efficient methanol reforming method could take 10 minutes to warm
up. "If that's the case," he says, "you close up shop," because drivers
wouldn't wait that long. Other kinds of reformers could start up much
faster, though they have other problems--like operating at very high
temperatures.
The second potential killer is "transient response," how quickly a car
responds when a driver mashes the accelerator. A gasoline engine responds
in milliseconds, as does a fuel cell running on pure hydrogen. But a
reformer that reacts slowly would mean a sluggish car, and drivers would
reject it.
There is a big debate about whether to go with methanol or gasoline. Many
experts prefer methanol because it is more efficient. But unlike gasoline,
methanol would require a new infrastructure to make and sell it. Still,
reforming either fuel would result in much less carbon dioxide than is
produced by the best internal combustion engines today. If fuel cells
become popular, a hydrogen infrastructure could be developed that would
reduce CO2 output. At first, hydrogen would be made from natural gas, as is
methanol. But if oil and natural gas run low, hydrogen could be produced
with solar electricity and water, resulting in a totally renewable energy
economy in which no global warming gases are produced.
Daimler-Benz, Ford, and Toyota all lean toward methanol, because it has
three hydrogen atoms for every carbon atom. Methanol produces less carbon
dioxide than does gasoline, which has two hydrogens for every carbon. GM
claims to be agnostic in the fuel debate. And Chrysler, which will buy fuel
cells from Ballard and electric drivetrains from Delphi, a GM subsidiary,
loudly champions gasoline, because the infrastructure is already in place.
"If we can develop a reformer to run on gasoline," says Chris Borroni-Bird,
Chrysler's technical strategy planning manager, "it will run on other
fuels."
Some experts also argue that there is little difference in CO2 production
between methanol and gasoline if all processes, from wellhead to wheel, are
taken into account. Oil companies, which are working uncharacteristically
closely with the car makers on this issue, naturally favor reformers that
process gasoline or kerosene made from crude oil.
If reformers can be perfected, then cost is the last major hurdle. Asked
what kinds of vehicles Ford might put fuel cells in, Bates replied, "If you
can beat the price of an internal combustion power train, then guess what,
the answer is, 'all vehicles.' And if you can't make them cheap enough, the
answer is 'no vehicles,' because our customers are king." Before fuel-cell
cars take to the road, other innovative, high-mileage, low-polluting
propulsion systems such as advanced direct-injection diesel engines and
hybrids that meld electric and internal combustion engines will appear.
"We're going to see more diesels," predicts Ford's John Wallace. That's
because new diesel engines no longer clatter like the old ones: They start
easily, they perform as well as gasoline engines, and they offer roughly a
56 percent improvement in fuel economy (and 24 percent reduction in CO2)
compared with gasoline engines. A likely target for the new diesel engines:
sport utility vehicles. For example, Japan's Isuzu, which is partly owned
by GM, is developing new diesels to be used throughout GM. There's one big
catch, however. It's not yet clear that the new diesels can meet strict
future air-pollution standards.
Mix and match. While American auto makers have promised to show "production
ready" hybrid vehicles early in the next century, Toyota is already doing a
brisk business selling the world's first commercially available hybrid, the
Prius, which went on sale last December in Japan. The four-door cars are
somewhat larger than a Corolla yet get 66 miles per gallon on the Japanese
test cycle and an estimated 55 mpg on the higher-speed American EPA test,
plus can hit 100 mph. They are so popular that Toyota this month raised
production from 1,200 a month to 2,000. The cars retail for $16,800 but are
believed to cost Toyota about twice that to make. The car maker is willing
to take a loss at first to get the market started.
Toyota has only one Prius in the United States to demonstrate, but American
auto manufacturers have purchased them and are trying them out on their
test tracks. "It's an outstanding engineering implementation of the hybrid
concept," says a Big Three engineer admiringly. Here's how it works: Stop
at a light and the small, slow-speed gasoline engine switches off. When the
light changes, the car moves off silently under electric power. When the
driver demands more speed, the engine turns itself on. Cruising on the
highway, the gasoline engine supplies the power, so Prius has the same
range and fuel supply as a straight gasoline car. For maximum acceleration,
both the engine and the battery drive the wheels.
The Prius, or something like it, will come to America in two years or so,
Toyota says. American auto makers, who are developing their own hybrids
under the industry-government Partnership for a New Generation of Vehicles,
are skeptical about its prospects here. "The best market in the world for
hybrids is Japan," says Wallace, because of the nation's slow, stop-and-go
traffic patterns. Hybrids capture part of the braking energy to recharge
the battery, increasing fuel economy. They're less likely to show much
advantage where speeds are constant. "At 70 mph on the freeway, a hybrid
only hurts" because the heavy, expensive electric power system isn't being
employed, says Mike Tamor, a hybrid project leader at Ford. Hybrids are not
likely to be shown at all in Europe, where traffic really moves. Engineers
at Daimler-Benz, for example, can't understand why anyone would want to pay
for two separate drivetrains in the same car.
Chrysler's hybrid prototype, the sleek, aerodynamic Dodge Intrepid ESX2-
-which the company calls a "mybrid," for mild hybrid--depends on a direct-
injection turbo-diesel engine to propel the full-size car. The electric
drive helps a bit during acceleration, moves the car in reverse, and
provides power for accessories. With the diesel engine alone, the car gets
63 miles per gallon. Adding the hybrid electric drive raises the figure to
70 mpg. According to computer simulations, a Jeep Grand Cherokee with the
same mybrid power train would get about 35 mpg.
One of the big reasons for ESX2's high mileage is that it weighs only 2,250
pounds (a 1998 Intrepid weighs 3,457 pounds) and offers less wind
resistance. The weight reduction was achieved by making the car's body out
of six pieces of injection-molded thermoplastic polyester, the same stuff
used for soft-drink bottles. Besides being lighter, it's expected to be
much cheaper to build in the factory. "It has to be, to pay for the power
train," says Steve Speth, Chrysler's hybrid program manager. Even so, the
company says the ESX2 would cost about $15,000 more than current cars.
That's the dilemma. With gasoline so cheap in the United States, it's hard
for consumers to become excited about the prospect of an 80-mile-per-
gallon car, the target of the Partnership for a New Generation of Vehicles
project. Someone who drives 15,000 miles a year in an SUV that gets 20
miles per gallon spends $937 for gasoline at $1.25 a gallon. If the same
SUV got 80 miles per gallon, the driver would spend $234 going the same
distance, an annual savings of about $700. Over the seven-year life of that
SUV, the driver would save less than $5,000, so that's the most Americans
could be expected to pay extra to get supermileage.
In other parts of the world, however, fuel costs are much steeper, making
high-mileage vehicles attractive. And there may be another factor at work
that could also help speed their development. "Consumers are placing the
environment in a greater role," says Mark Amstock of Toyota. "We think
there are market-driven opportunities" for cleaner, more efficient cars.
Few question that gasoline engines will be around for a long time. Yet,
says GM's Harry Pearce, "I don't doubt that over the next 25 years
alternative propulsion vehicles as a group will make up 25 percent of GM's
fleet in the United States." And that, in the context of the past 100 years
of auto manufacturing, would be a revolutionary rate of change.
FUTURE CAR ENGINE
Fuel cells that make electricity could power cars as soon as 2004.
Advantages are low emissions and high fuel economy. Getting fuel cells'
cost down will be a big problem.
Fuel-cell car. Many auto companies are working on fuel-cell cars. Daimler-
Benz has been demonstrating a test car based on the small Mercedes-Benz
A-class subcompact.
Electric motor. Fuel-cell cars would use electronics and electronic motors
similar to those in battery-powered cars.
Fuel tank. Vehicles carry methanol or gasoline for fuel. Range of the fuel-
cell electric car would depend on tank size and would be about the same as
for similar gasoline cars.
Fuel processor. Pure hydrogen for the fuel cell is extracted from methanol
or gasoline in a fuel processor also called a "reformer," which is a tiny
chemical plant carried in the car.
Stacking up power. The electric power plant consists of many individual
fuel cells put together in a "stack." The number of cells determines total
power output.
Single cell. One cell consists of two electrodes--the anode and the
cathode-- each coated with a thin layer of platinum catalyst. Hydrogen fuel
and air (which provides oxygen) flow through the cell to generate an
electric current.
Generating electricity
A fuel cell generates electricity by combining oxygen and hydrogen. The
electrochemical process operates at relatively low temperature and produces
water vapor as a byproduct. Here's how a fuel cell works:
1. Hydrogen flows through channels to the anode. Oxygen from the air flows
to the cathode. The cathode and anode are separated by a plastic proton
exchange membrane.
2. At the anode, hydrogen is disassociated into electrons and protons by
reacting with the platinum catalyst. Protons pass through the membrane to
the cathode.
3. Free electrons flow as an electric current through a motor to the cathode.
4. At the cathode, electrons and protons react with oxygen from the air to
form water.
Weight and cost reduction
Cars that weigh less can provide good performance with smaller, more
economical engines. Auto makers are experimenting with structures made of
aluminum, lightweight steel, and plastic ...
... Chrysler, for example, has developed a full-size sedan with a body
structure that consist of six large panels made of the same kind of plastic
used for soft-drink bottles. The panels are formed in large molds similar
to small ones used to make plastic toys and other objects. The six plastic
pieces weigh half as much as the 80 pieces of steel that are welded
together to make a standard sedan. Chrysler calculates that plastic bodies
also will cost less than present versions.
{Illustration labels}: Fuel-cell stack; Oxygen; Catalyst; Membrane; Anode;
Electric current; Cathode; Electron; Proton; Water; Single fuel cell;
Disassembled plastic car (ESX2); Plastic body parts; Aluminum frame;
Assembled ESX2
Source: Ballard Power Systems, Chrysler Corp., Daimler-Benz
(Copyright 1998)
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