The car of the future whirs like an old refrigerator and steams like a teapot.
It took to the roads of Washington, D.C., last month despite being less than ready for prime time.
Fuel-cell vehicles like the Mercedes-Benz NECAR4, billed as the first fuel-cell vehicle to hit US roads, are, however, emerging as the most likely long-range successors to today's polluting, gasoline-powered, internal-combustion cars.
That's because cars like NECAR4 get 65 miles per gallon, have no emissions other than water, go 280 miles before refueling, refill in little more time than it takes to top up your gas tank, and have almost no moving parts to break down, says Juergen Schrempp, co-chairman of DaimlerChrysler.
What's significant is this car's size. Past fuel cells have filled entire vans or city buses. But the NECAR4 is a small Mercedes-Benz commuter car only sold in Europe. It has room for five passengers and a tiny cargo space.
DaimlerChrysler promises fuel-cell powered cars will hit the US market by 2004, though most will probably be powered by something less utopian than the hydrogen that runs NECAR4.
Fuel-cell vehicles are essentially electric. The fuel cell produces the electricity that runs the motor that drives the wheels. Powered by hydrogen, the cars qualify as zero-emissions vehicles.
Until now, most zero-emissions lobbyists have been focusing on battery-powered electric cars. But Paul Lancaster of Ballard Power systems, the company that designed NECAR4's fuel cells, says batteries have two intractable problems:
*They have low-energy density. That is they don't store nearly as much energy for their weight and size as do fossil fuels.
Batterymakers are scrambling to overcome this shortcoming with new chemical formulas such as nickel-metal hydride and lithium-ion batteries. But such technologies are hugely expensive and still don't provide enough power to drive an electric car with anything like the range of a gasoline engine.
In the GM EV1 electric car, for instance, the nickel-metal hydride battery pack costs more than $60,000 and provides a maximum range of 130 miles.
*They take hours to recharge. More-over, the faster you recharge them, the shorter their range and the sooner they have to be replaced, Mr. Lancaster says.
Fuel cells are also a long way from being cheap enough and light enough for the consumer market.
The primary problems have to do with distribution and storage of hydrogen. Hybrid vehicles that switch between a gasoline engine and batteries will likely fill the gap. Two will be sold in the US next year that will get better mileage than NECAR4. But they still pollute.
Like batteries, gaseous hydrogen requires a much larger container to store as much energy as gasoline. The NECAR4 carries liquid hydrogen -stored at 23 degrees above absolute zero -to fit enough fuel into its tiny body. Filling it up is more complicated than gasoline, but no more time-consuming than filling a liquid-propane tank.
Behind the wheel, NECAR4 is upright and rather cramped with four large men on board. The only sound that goes with start-up is the faint whirring of an air compressor that supplies oxygen to the fuel cell. That's what sounds like an old refrigerator, rising and falling in pitch a moment after you step on or release the gas. Otherwise the car is silent.
Loaded with passengers, the car feels stuck in molasses, unlike other electrics that hold only two passengers but accelerate briskly up to 30 miles per hour.
The fuel cell works by storing hydrogen and oxygen on opposite sides of a porous plastic barrier. An electrical circuit that runs the motor connects the two. When the circuit is closed, the hydrogen's fickle electron races around the circuit to join the oxygen. The remaining hydrogen proton is pulled through the plastic membrane and bonds with oxygen to make water. No combustion, no emissions -not even carbon dioxide.
The refueling infrastructure is the biggest obstacle to selling fuel-cell vehicles, says Ferdinand Panik, head fuel-cell engineer at DaimlerChrysler. Today's gas stations would be expensive to convert to hydrogen. So cheaper alternatives may predominate -chiefly methanol, which can be installed for less than 20 percent the cost of hydrogen.
But using methanol has drawbacks. The catalytic converter that converts methanol to hydrogen, called a reformer, produces "trace" emissions and saps efficiency. It also adds weight and cost. Dr. Panik predicts methanol will power fuel-cell cars the public buys, while fleet customers and those in California, Massachusetts, and New York will buy hydrogen.
Chrysler also displayed a fuel-cell powered vehicle in Detroit that runs on gasoline. And DaimlerChrysler is working on a fuel cell that uses methanol directly. But those technologies may take 10 years to develop, Panik says.
DaimlerChrysler isn't the only manufacturer focusing on fuel cells. "Of all the alternatives we deal with, we think fuel cells are the most likely to succeed," says Sara Tatchio, spokeswoman for Ford's environmental vehicles program. Ford is working with Ballard and DaimlerChrysler on developing fuel-cell cars. Toyota is researching fuel-cell technology, while BMW plans to sell a car next year that uses a fuel cell in place of its battery, although the engine still runs on gasoline.
Beyond the refueling infrastructure, the other big obstacle is cost. The NECAR4 is 10 times too expensive and 600 pounds overweight, says Panik.
But those figures are coming down. For a given amount of energy the fuel-cells produce, their weight and cost have fallen 90 percent since 1990, says Lancaster.
Ballard is working with other researchers on ways to store hydrogen. Even small cars could store enough hydrogen, if the whole body structure were designed as a fuel tank, says Lancaster.
Critics scoff at the notion of turning a car full of volatile hydrogen gas loose in urban traffic. But the tanks that store hydrogen in the three fuel-cell buses that Chicago has been testing since last year are certified to carry explosive natural gas.
Daimler has also proposed a model that uses home refueling stations to fill fuel-cell cars with hydrogen. Hydrogen could be piped to homes like natural gas and used to provide home electricity and heat as well.
In the end, there's an argument that the effort automakers put in building fuel cells may be buying them time to clean up internal-combustion engines, says Brett Smith, at the University of Michigan. "It makes them look like they're doing something."
Still, automakers have made a dramatic shift to fuel cells from studying batteries to meet tough zero-emission-vehicle mandates in California and Massachusetts by 2003. New York also had such a law, but it was overturned last August when it became clear that battery technology is not yet practical in colder climes.
"Massachusetts [whose law is still on the books] hasn't figured out that it's in the north, where you need this much power just to run your heater," says Smith. Still, he credits California as having "stolen the mandate from the EPA" to produce cleaner vehicles. Without that mandate, he says, alternative-fuel vehicles would still be sitting in the garage.