Fuel cells and diesel hybrids are the future, says Zetsche

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Mercedes' Dieter Zetsche is confident that fuel cells are still in the frame for volume production.

Dieter Zetsche, Chairman of the Board of Management of Daimler AG and Head of Mercedes-Benz Cars, told AEI at the Geneva Motor Show that the company's fuel-cell and diesel-hybrid programs were progressing. Next year will see a gasoline hybrid (in the S-Class) and a diesel hybrid would enter the Mercedes range "one to two years after."

Diesel hybrids will include the C-Class and, later, other models. BlueTEC diesel models have a cost penalty, said Zetsche, and a diesel hybrid BlueTEC even more so. "Our task is to drive down the cost of these incremental technologies, and beyond that, offset a portion of this cost via further efficiency gains in the rest of the vehicle and to pass over part of that cost to our customers in the knowledge that they will save money with lower fuel bills."

The Mercedes model range is now exceptionally wide, and the company is constantly changing or improving its lineup and adding niche vehicles, but Zetsche made it clear that there is a limit to this. "We do not see an unlimited expansion of the scope of our product portfolio," he said. "But this is independent of what we will do on the CO₂ front; we have not sacrificed any movements in our product portfolio because of CO₂."

The possibility of a cooperative architecture—or platform—program with another OEM to develop a new small Mercedes has now receded. "Our discussions with various OEMs took us to the conclusion that there is no scenario where both partners would benefit from such a cooperation," he said. "So we are not pursuing that idea any further. However, there are clear indications that the outcome could be different with regard to components in those vehicles. We are having ongoing discussions in the first place with BMW. They are promising, but have not led to a result. Both sides want such a cooperation to happen, but it depends on the economic feasibility of working together, and we do not have the final outcome of those studies. The discussions concern powertrain."

Zetsche underlined Mercedes' intention of continuing to reduce CO₂ emissions on all of its vehicles and to continue to give its customers safe, luxurious, and, when necessary, large cars "with less emissions and ultimately with no emissions." He said he regarded this as a realistic goal toward which the company was working, and that it would accomplish its aims.

One way to do this was to introduce series-production fuel-cell cars, he said. While many OEMs are now very cautious about the potential of fuel-cell technology and its possible timing—even looking to 2020-2025 and beyond—Zetsche said Mercedes was very serious about pursuing it. Some companies now appear to be reducing the priority they put on fuel-cell research, but Mercedes is doing the opposite.

"In 2010, we will begin with series production of one a day (not really mass production but it is a start) in the B-Class," said Zetsche. "And while some time ago we came to the conviction that we could offer a totally competitive product based on a fuel cell in the foreseeable future, we did not consider this could be done on an economically feasible basis.

"Meanwhile, we have invested a lot of time, brains, and money into the development and ultimately mass production for fuel cells, with the result that today we are convinced that by 2014-2015 we can offer technically and economically competitive fuel-cell vehicles in the range of 100,000-plus units a year."

Zetsche said that Mercedes was willing to go for that target and "not play the chicken-and-egg game" of saying first there needed to be the infrastructure to support fuel-cell cars and only then would the vehicles be produced in volume. "But we cannot invest a lot of money and then find there is no infrastructure—and will not be—and have to put what we have built into a museum," he said.

The next challenge was to establish partnerships to prepare and put in place the necessary infrastructure. "The beauty is that almost everything on a fuel-cell vehicle is identical with a full electric vehicle, except a large battery to store the power and energy versus a hydrogen tank and converter to power the fuel cell."

As for vehicle range, Zetsche regards more than 400 km (250 mi) as feasible, while purely battery-powered vehicles can only manage 100 km (62 mi). And there is the issue of recharge time: 2 min for a fuel-cell vehicle vs. maybe 6 h for a battery vehicle.

"We are very, very serious about fuel cells," he said. "We will have mass-production vehicles without emissions in the timeframe I have outlined. We have to."

And would the unit cost to the consumer be within the range of a conventional powertrain in the 2015 timeframe? Today, that looks like a stretch, said Zetsche, but it is an achievable target.

And a volume fuel-cell car would need to be immediately distinguishable from other cars on the road and might also be bigger. "We learned from the Prius that with a new technology it is essential for the neighbors to ask the owner, 'What is that you are driving?'"

Mercedes-Benz also has been winter testing a fuel-cell B-Class model, particularly focused on its cold-start performance. Although Daimler researchers had found a technical solution to the fuel cell's start capability at -25°C (-13°F), the engineering focus was on the interaction between different components under real-world winter conditions.

What the company described as a "new generation" of compact fuel-cell drive would be used to power the first of the B-Class production cars in 2010, providing better performance than previous-generation examples. The technical basis for the system, used in the company's F600 Hygenius research vehicle first seen in 2005, includes a stack about 40% smaller than early-generation fuel-cell designs, according to Mercedes, but generates 30% more power with a 16% reduction in fuel consumption. The system demonstrates a good cold-start capability thanks to innovations such as the electric turbocharger for air supply and new humidification and demisting system.

In the B-Class fuel-cell car, the electric motor has a 100-kW output and maximum 320 N•m (236 lb•ft). Fuel consumption is cited as being 2.9 L (diesel equivalent) per 100 km. Mercedes is operating a 100-vehicle fuel-cell test fleet.

Stuart Birch