Fri12192014

On The Road

What's up with fuel cells?: Mercedes-Benz makes a case for eco-friendly technology

Photo Courtesy Of Mercedes-Benz This California Fuel Cell Partnership facility in Long Beach is one of only a handful of places in the state to fill up fuel-cell cars such as the Mercedes Benz F-Cell.

With the recent news about electric cars, plug-in hybrids and the new serial hybrids propelled by electric motors powered by batteries that are recharged by gasoline engines, we might be forgiven for forgetting that fuel cells were once the wave of the future.

We were reminded of this when Gary was invited last month to drive one of the legs of the Mercedes-Benz F-Cell World Drive. As part of the commemoration of the 125th anniversary of the automobile Mercedes invented, the company has dispatched three hydrogen fuel-cell cars to be driven around the world in 125 days.

The tour began in Stuttgart, Germany, Jan. 29 – 125 years to the day in 1886 when Gottlieb Daimler filed his patent for the first wheeled vehicle powered by an internal combustion engine. Before they return home, the cars will have been driven more than 20,000 miles across four continents (Europe, North America, Australia and Asia) and traveled through 14 countries. The cars – recently flown from Seattle to Melbourne, Australia – have had no problems thus far.

Our stint was to drive one of the cars from New Orleans to San Antonio through Houston and Austin. The two-day drive covered approximately 800 miles, most of them over flat, straight interstates and windy backroads in Texas Hill Country.

The journalist/drivers all agreed that the biggest sensation was one of boredom. The car is totally quiet, comfortable, easy to drive and can travel up to 300 miles between refuelings, an equivalent of 71 miles per gallon of diesel fuel. It has no emissions other than the water vapor coming out of the tail pipe.

In the simplest terms, the technology is straightforward. Hydrogen is stored under pressure in carbon-fiber reinforced tanks under the rear seats. It is fed into a fuel cell approximately the size of a briefcase under the front passenger seat. Using technology developed for the space program in the 1960s, the hydrogen combines with oxygen in the fuel cell, giving off electricity in the process. This requires platinum as a catalyst, but the latest versions use approximately the same amount of platinum as a catalytic converter, which these cars don’t require.

The electricity in turn drives an electric motor connected by a differential to the front wheels. When the car slows down, a small lithium-ion battery in the engine compartment captures braking energy. The battery runs the accessories and can add power to the motor for acceleration.

Aside from the silence of the electric drive, there aren’t any differences from driving a standard car. With the high-torque electric motor, the car can reach highway speeds or dart through traffic as required. It has a top speed of 110 mph, but because the distances between the fueling points were significant, we were asked to use good fuel-saving practices. We kept the car cruising at an easy 65 mph, pretty much the optimum speed for any car to make its best mileage.

Externally, the car looks identical to the standard Mercedes-Benz B-Class sold in Europe (though not in the United States). The closest comparable car here is the Honda Fit. The interior and luggage space is exactly the same as in other compact cars. One thing we did notice: Despite four three-hour stints at the wheel over two days, given the smoothness of the drivetrain and the quality of the Mercedes seats, we didn’t experience driver fatigue.

So, why can’t you buy one of these great little cars as a 2012 model? You may actually spot some in the Bay Area later this year, because 100 of them are leased to private owners here and in Los Angeles for three years.

The limitation? They can’t drive more than 150 miles from the nearest hydrogen pump. That’s the rub. Although hydrogen is widely available – around the world, in fact, and in a number of industrial and food-processing applications – there aren’t any filling stations ready to store and pressurize the gas for automobile use.

The first guinea-pig owners in California will be tethered to the few government and industrial fueling sites here and in Southern California. On the World Drive, Mercedes provides a tank truck with hydrogen and a fueling station in a Sprinter van and trailer following the cars to fuel them twice each day

Does that make the technology less practical than battery-electric power? After all, everyone has electricity in their homes, so owners of Teslas, Nissan LEAFs, and Mitsubishi i MiEVs can recharge at home. The problem is that with current battery technology, it takes four to eight hours to recharge a plug-in car to capacity, and it can only go 50-100 miles. In contrast, the fuel-cell car can refuel in 10 minutes and easily go 250 miles.

Direct use of electricity by storing it in the battery pack is a little cheaper than converting it to hydrogen and then back into electricity, but unlike the plug-in car battery packs, the fuel cell is small and easily recycled – another environmental plus for the fuel cells.

One other issue must be resolved. The fuel cell has to be manufactured at a cost equivalent to a comparable battery pack as used in an electric car. Mercedes is convinced that at reasonable volumes, that will be possible.

So now we wait – most experts predict at least five years – to find out whether the world can develop more efficient techniques for storing electricity than current batteries sooner than it can establish a distribution network for hydrogen.

Oh, and then we have to figure out how to safely generate the electricity we will need, which as of a few weeks ago has again become an issue. But no one said solving our environmental problems and reducing our dependence on fossil fuel would be easy.

 

 

Longtime Los Altos residents Gary and Genie Anderson are co-owners of Enthusiast Publications LLC, which edits several car club magazines and contributes articles and columns to automotive magazines and online services.

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