Will we ever see fuel cell cars on the road? Many critics feel that government support for this technology is misguided, with far better options available for alternative-fuel, “green” transportation. While the fuel cell concept is simple, implementation faces major hurdles. For example, there are more than 170,000 gas stations in the United States and so far well under 100 hydrogen counterparts.
|Honda’s FCX “Clarity” advanced fuel cell vehicle.|
Here is the basic science behind the operation of a fuel cell vehicle: Air blows across one side of a permeable film while hydrogen passes across the other side. The film serves as a catalyst to combine two hydrogen molecules with one oxygen to release an electron and thus create electricity with water and heat being the only by-products. When that reaction occurs in sufficient volume, power is generated to fuel a vehicle. Since air is out there for the taking and water vapor won’t hurt the environment, the technology has attracted followers, including the Bush administration.
Even at this point, however, there’s a significant, if somewhat overlooked hurdle to the viability of fuel cell transportation. The most popular material for the catalyst required to cause the hydrogen/oxygen reaction is platinum. At the current level of the technology’s evolution the required amount of catalyst per kilowatt is 0.018 – 0.028 ounces (0.5 – 0.8 grams). Platinum costs roughly $1,500 an ounce, which means the catalyst alone in a 100 kilowatt fuel cell engine (one kilowatt is equivalent to 1.34 horsepower) runs between $2,600 to $4,200. A comparable gasoline engine costs approximately $3,000 total. Platinum isn’t going to drop in value just because car makers are producing more fuel cell vehicles – the opposite is more likely.
Another significant barrier to adoption of fuel cell vehicles is the hydrogen itself. It isn’t readily available and currently costs twice as much as gasoline for the same quantity of energy. The inability to actually pull up to a hydrogen pump to refuel is an even bigger problem. Currently there is one hydrogen fueling station in Washington, three in Las Vegas, and a smattering in Detroit mainly for automakers’ testing purposes. The best place to be a fuel-cell driver is California where there are two dozen stations in and around the Los Angeles, San Diego, San Francisco and Sacramento areas, with fourteen more on the way. Given these limitations and the current level of prototype development, only two fuel cell vehicles will actually be in the hands of a limited numbers of drivers next year, the Honda FCX and an experimental version of the General Motors Equinox SUV.
Honda plans to offer a limited run of its FCX fuel-cell sedan for the 2008 model year. The FCX is a four-door with front-wheel drive. The engine produces 127 horsepower and returns 68 miles per gallon (running 270 miles on a tank). A kilogram of hydrogen has almost exactly the same energy as a gallon of gasoline. Since Americans have an innate understanding of “I can go this far on a gallon,” manufacturers offer fuel cell performance ratings in language people will instantly understand.
In actuality, of course, the 2006 version of the Honda FCX was equipped with a 3.75 kilogram tank. (The 2008 is said to have a slightly larger tank, but the specs are still vague.) With that fuel capacity, the 2006 FCX returned 62 miles per kilogram (mpkg) for city driving and 51 mpkg on the highway. With a larger tank and other improvements, it’s fair to assume the 2008 will do that well and most probably a bit better.
Honda has reduced the size of the fuel cell and positioned it vertically in a center tunnel running between the driver and front passenger under the armrests. The size and positioning, according to the company, makes the water flow faster and concentrates heat to decrease the risk of freezing and to increase the speed of power production. Honda has mounted the electric motor on top of the front wheels and the fuel tank and battery pack (lithium ion) are behind the backseat.
In January, General Motors will put a fleet of 100 fuel cell Chevrolet Equinox SUVs in the hands of consumers for three months, a test that will be repeated with a new group for an overall study of 30 months duration. Interested parties can go to the Chevrolet website to sign up, but you must live in Los Angeles, New York, or Washington. Dubbed “Project Driveway,” the effort also involves the installation of four new hydrogen fueling stations in New York and six in Los Angeles. The Equinox SUVs to be used in the test have a range of only 150 miles per tank — well, make that three carbon fiber tanks — stacked up under the rear seat and in the cargo area. These tanks have a combined capacity of 4.2 kilograms with the vehicle rating 35 mpkg for in-town driving and 45 mpkg on the road.
The big question with fuel-cell technology is not if it works. It does. Placement of the fuel cells and powertrain elements is far from refined, however, and both the Honda FCX and the GM Equinox have limited ranges. Other automakers have their hats in the ring as well, with Daimler AG and Ford Motor Co. just announcing their acquisition of Canada’s Ballard Power Systems, an automotive fuel cell business, in November 2007. The deal was inked for the express purpose of further research and development. It’s clear, then, that automotive bucks continue to flow in the direction of fuel-cell technology, but we won’t see fuel-cell cars on American roads in any significant numbers until hydrogen flows just as readily. And right now, that’s just not the case.