If director Mike Nichols were to write a sequel to his 1969 classic The Graduate, the career-counseling mantra offered to a present-day Benjamin Braddock might well be "fuel cells" instead of "plastics."

In less than a year, this formerly esoteric technology used in the Gemini and Apollo space shots has emerged from the National Aeronautics and Space Administration's closet to become a credible candidate to supplant the internal combustion engine by the middle of the 21st century.

Daimler-Benz AG (D-B) and Ford Motor Co. have invested more than $620 million in Ballard Power Systems Inc., the Vancouver, BC, company that has established itself as the leading developer of proton-exchange-membrane fuel cells, which can power electric vehicles and stationary power-generating stations. (see feature, p.75).

They're still too expensive. The jury will be out for a long while as to whether their overall performance will satisfy horsepower-hungry Americans.

Yet to better understand why fuel cells are being taken seriously, consider the following:

n It would cost about $30,000 to produce a fuel-cell powertrain capable of the same performance as an average 4-cyl. internal combustion engine and transmission costing about $3,000. But 10 years ago it would have cost $3 million.

n The ability to reform gasoline or methanol on-board reduces the time required to reach full power from about five minutes to between one and two minutes.

n The amount of platinum required for the fuel-cell stacks has come down significantly, and research is beginning to find lower-cost catalytic agents such as palladium and ruthenium.

General Motors Corp. has declared it will have a "production-ready" fuel-cell car by 2004. Chrysler Corp. is committed to delivering a "proof-of-concept" fuel-cell prototype by January 1999.

Ford and Daimler-Benz have set a goal of building more than 100,000 fuel-cell cars annually by 2004.

"Long-term, I have no question that we are going to shift toward electro-motive drive-trains," says Henry R. Linden, professor of energy and power engineering at Illinois Institute of Technology in Chicago. "Not necessarily because of global climate change, but because the existing internal combustion technology is over 100 years old. It's like still using steam engines for railroads."

The most formidable challenges confronting fuel cells have been the availability of hydrogen and the cumbersome on-board storage of a gaseous fuel. Because hydrogen is a gas, it would take up many times more space than an energy-equivalent amount of gasoline. To convert hydrogen to a liquid state, it would have to be cooled to an impractical -420_F (-251_C).

But last October, Arthur D. Little Inc., the U.S. Department of Energy and Plug Power LLC said they had developed a gasoline reformer that efficiently extracts hydrogen from gasoline. That raises the possibility of converting gasoline to hydrogen on-board the car, a major breakthrough.

First, it goes a long way toward overcoming the lack of an existing infrastructure for distributing and selling hydrogen.

Secondly, it keeps the politically powerful petroleum industry in the loop because reformulated gasoline would still be the fuel of choice.

Maybe.

Converting methanol to hydrogen through an on-board reformer is the route Ford and D-B want to take in their partnership with Ballard.

Why not gasoline?

"First, the partial-oxidation reformer of gasoline is nowhere near as mature a technology as the steam-oxidation reformer for methanol," says John R. Wallace, director of Ford's alternative fuel vehicles program. "The second factor is that gasoline is not a manufactured product. It's got all kinds of stuff in it. It's got sulfur, benzene; it's like a Mulligan's stew. Plus there are fewer hydrogen molecules, relative to the amount of carbon you generate, than you find in methanol."

With either gasoline or hydrogen, on-board reformers must overcome another problem. Once they strip off the hydrogen molecules, the reformers leave both carbon dioxide and carbon monoxide as byproducts. Of course, carbon dioxide is the greenhouse gas everyone wants to minimize or eliminate. Carbon monoxide not only poisons humans, it also binds permanently to the platinum in the system's catalytic converter, destroying its ability to provide hydrogen in a pure enough form to be used in the fuel-cell stack.

One solution is to introduce a second catalytic converter to transform the CO to CO2.

Another is to use pure hydrogen.

"The trouble is, if you focus on that, you don't work on the reformer, then you are waiting for the next millennium, I mean the 22nd century, waiting for a hydrogen infrastructure," Mr. Wallace says.

Byron McCormick, director of General Motors' Fuel Cell program, agrees that methanol is preferable to gasoline, but like every major automaker, GM is working with oil-industry partners - in GM's case, projects under way with Amoco, Exxon and Arco - to find new gasoline mixtures that could be converted more efficiently to hydrogen.

Just what would a fuel-cell car look like?

In their January presentation, GM officials said they are investigating the possibility of mounting a fuel-cell propulsion system, supplemented by batteries, in an EV1 that has been stretched 19 ins. (48 cm) to accommodate four, ra ther than two, passengers.

Mercedes-Benz has focused on its NECAR 3, based on the A-Class city car.

A wide range of unresolved issues still lingers.

The fuel-cell stacks are only one part of the powertrain. An affordable electric drive system and a battery with greater energy density than those in the first generation of EVs are also needed.

Except in terms of surprisingly strong torque in the low rpm range, fuel cells are a long way from equaling their internal combustion (IC) forebears in performance.

"There's a much steeper linear association between size of the powertrain and cost," says Ford's Mr. Wallace. "In other words, for IC engines a V-8 is not really that much more than a 6, which isn't much more than a 4. But with fuel cells, if you have twice the horsepower it's much closer to being twice the cost."

In short, this is not like waiting for the Pentium III, or whatever the next quantum leap in microprocessors will be.

"A good 10 years of solid research and development is still needed," says Christopher Borroni-Bird, Chrysler Corp.'s advanced technology specialist. "I don't see mass production of fuel-cell cars before 2010."

That may be optimistic.

Peter Lehman, director of the L.W. Schatz Energy Research Laboratory at Humboldt State University in Arcata, CA, is about as avid a supporter of fuel cells as you will find. He has shepherded a pilot fleet of fuel-cell-propelled golf carts used by city employees in Palm Desert, CA. But he doesn't see mass production being economically feasible until 2020 or 2025.

"The good news is that the Big Three are finally seeing the handwriting on the wall," Mr. Lehman says. "Daimler's decision to partner with Ballard was kind of a kick in the pants. They felt the train was leaving the station, and they didn't want to be left behind."

The first widespread production most likely will occur in Europe, where gasoline pump prices are four or five times higher, and global warming is taken far more seriously than in the U.S.

And perhaps the most serious drawback to this new-tech propulsion system is the billions of dollars already invested in engine and transmission plants. Who wants to walk away from that kind of commitment when the technology remains affordable and satisfies customers?

"If your vision of the future 10 years out is it's just like today only with faster personal computers, there's no incentive," says John Wallace. "It's really a waste of time to predict the future because there is so much uncertainty. But it is not a waste of time to predict the range of possibilities."