The Fuel Cell

It seems like the proverbial magic bullet. Imagine if you will, an energy source that leaves no residue except some water and a bit of carbon dioxide. Nor does it produce particulates, nitrous oxides, carbon monoxide or anything else that might cause environmentalists to moan. Unlike the typical gasoline or diesel automobile engine, the fuel cell doesn't even use combustion to create power. Instead it uses a simple chemical reaction to make electricity, which can then be used to power electric motors and electronic equipment or stored in batteries for future use.

If all this seems too good to be true, here's a fact: fuel cells have been used in the U.S. space program since the 1960s and today they are used to provide reliable power for out-of-the-way hotels and hospitals that find it too expensive to tap into traditional electric power grids. So why hasn't the auto industry jumped on this technology long before now? Well, actually the industry has toyed with fuel cells for decades, but only in the last several years, with the bogey of having to market so-called zero-emissions vehicles mandated by law, has the industry become serious about employing fuel cell technology. Now, though, major players like General Motors, Ford Motor Company, Toyota and DaimlerChrysler are working overtime to bring fuel cell vehicles to the market.

A quick glance at the technology of the fuel cell: It's somewhat synonymous with a storage battery that doesn't require recharging. Like a battery, it consists of two electrodes around an electrolyte. Oxygen passes over one electrode and a fuel, hydrogen passes over the other, resulting in a chemical reaction that creates a flow of electrons (electricity), heat and a hydrogen-oxygen combination commonly called "water." Unlike batteries that "run down" after continuous discharge, fuel cells will continue to make electricity, heat and water as long as they are provided with oxygen and hydrogen. Unlike the typical vehicle engine, which converts energy stored in its fuel to usable power via combustion (i.e., "burning"), fuel cells chemically combine the molecules of a fuel and an oxidizer without burning, dispensing with the inefficiencies and pollution of traditional combustion.

In an era of constant tradeoffs, there seems to be nothing but an upside for fuel cell technology. But before you start whistling show tunes as you skip off merrily through a field of daisies, the technology does present challenges.

Perhaps the biggest challenge is the handling of the volatile element hydrogen. As proved in the grainy film footage of the explosion of the dirigible Hindenburg ("Oh, the humanity!"), hydrogen gas can be explosive. Given this, one trick in developing fuel cells that will work in vehicle applications is supplying and re-fueling the hydrogen. Various methods have been contemplated and tried, including cold storage of liquid hydrogen and various methods for storing hydrogen gas, but the most promising for real-world use seems to be the gasoline station on the corner. Gasoline (as well as other fuels) can be broken down to produce hydrogen, which can then be used in fuel cells.

Producing hydrogen from gasoline (or methanol or ethanol) is the job of a "reformer." The reformer is sort of an on-board "cracking plant" that separates hydrogen, which is a component of gasoline, from its other components. Of course, the use of an on-board reformer adds a great deal of complexity (and cost) to each fuel cell application. Further, building reformers that are compact enough for automotive use are problematical right now, though fuel cell advocates predict that obstacle will soon be conquered.

Even given the obstacles, reformer-fuel cell technology seems the most viable alternative for getting the technology into automobiles. Why? In the absence of reformers a whole new fuel delivery infrastructure would have to be created from scratch, and the costs of such an undertaking are staggering.

Global car manufacturers say fuel cell technology is coming. In fact, Ford Motor Company, which debuted what it called the world's first production-prototype, direct-hydrogen powered fuel cell late last year, says it is committed to offering fuel cell vehicles to customers by 2004. Other manufacturers are just as eager to be seen on this leading edge. But the internal combustion engine still has a great deal of life left in it. In fact, industry observers predict that gasoline-powered internal combustion engines will still power more than 50 percent of the world's vehicle fleet in 2050. Continue to tune in to DT to see if they are right.

--Jack Nerad

Jack R. Nerad, the co-host of the nationally syndicated radio program "America on the Road," usually runs out of energy around 10 pm.
by Jack R. Nerad