Exclusive: Daimler’s Director of Fuel Cells and Battery-Drive Explains Cautious Approach

By · March 14, 2011

Mercedes-Benz B-Class F-Cell hydrogen fuel cell car

The Mercedes-Benz B-Class F-Cell hydrogen fuel cell car in San Francisco.

Last week, I took a spin in the Mercedes-Benz B-Class F-Cell hydrogen fuel cell car, on the San Francisco leg of the “F-Cell World Drive.” As with almost all pure electric-drive cars, the ride was brisk, quiet and smooth—an uneventful ride that belies the profound transformation that battery- and fuel-cell-powered cars represent to the future of automobiles.

After the short drive, I caught up with Dr. Christian Mohrdieck, Daimler’s director of fuel cell and battery drive development, to learn about Daimler’s official positions on EVs versus fuel cell cars. In one sense, the company’s position seems contradictory. After all, Mercedes has a decent list of battery-powered cars on its roadmap: the A-Class E-Cell (produced in limited numbers in Europe); the Smart ED currently on lease in the United States; the S-Class plug-in hybrid (with 20 miles of all-electric range) announced in Frankfurt last year; and a four-seat electric car planned for production in partnership with Renault.

Yet, Dr. Mohrdieck makes no bones about his views on the limitation of electric cars. “If you need a larger vehicle, if you need long range, if you need short refueling times, then you have to have something else than batteries,” he told me.

Q and A

Dr. Christian Mohrdieck />

Dr. Christian Mohrdieck, director of fuel cell and battery drive development at Daimler.

Is the company putting as much emphasis on the F-cell as the E-cell (electric car)?

Yes. One way to see this is we are putting similar budgets on fuel cells and batteries at this point in time. There’s much more going to internal combustion engines and hybrids, because they are already high volume products. But we need to invest in the future and we try to do this in a very consistent and balanced way.

How rapidly is battery technology improving? And how fast is cost coming down?

I think battery technology has improved over the last decade to 15 years, and there’s still room for improvement. Battery progress is very tough. People think progress is faster than it really is. We want to get to $280 to $300 per kilowatt-hour in about 10 years. Right now, it’s about three times that cost.

How does this cost compare to the overall cost of fuel cell technology?

The cost of fuel cell technology per kWh is lower. The overall absolute system cost is higher because we have much more power on the fuel cell. But the potential for cost reduction on fuel cells is much bigger. Projections from MIT, for example, say fuel cell vehicles in the long run will be cheaper than battery electric vehicles. That’s one other reason we need to pursue this technology in parallel.

With the hope that hydrogen fuel infrastructure comes along?

That’s a hope you have for battery electric vehicles too, because most people driving city compact cars at least in Europe, they don’t have a garage. They don’t have a parking spot, so they need infrastructure because they’re living on the 10th floor. So, infrastructure is needed for battery-electric vehicles too. And you want to charge quicker than just with the grid, which takes many hours to charge.

Does the issue of net energy gain or loss to produce the hydrogen concern you?

Yes, the same thing concerns me with electricity. In the European Union’s regular electricity mix, the battery electric car is worse than the hydrogen fuel cell car when you make the hydrogen from natural gas, because there’s still a lot of fossil energy used to make electricity,

The efficiency of the battery electric car per se is higher because you don’t have so many conversion steps. Everything depends on how you make the electricity. Eventually, we want to make hydrogen from renewable sources, like solar, wind, hydro, and biomass. And then you have a very low CO2 level and you have all the advantages of cars today: long range, three-minute refueling, and it can be applied to even city buses, so very big vehicles.

Do you think the current rollout of battery electric vehicles from Japanese and American carmakers is happening too rapidly?

No. Because I see they are already changing their numbers. Nissan has reduced numbers and delayed introduction times, so I think nobody can ignore reality of electro-chemistry. I think the problems to be solved are the same for everybody.

How active is your partnership with Tesla?

It’s very active. Actually, I visited them today. They’re delivering batteries for two of our vehicles, the Smart and the A-Class. In order to have enough energy on the A-class E-cell, we put two batteries from the Smart EV, and we connected the batteries in a certain way. They are working together, to provide approximately 36 kWh. We have a lot room in this double floor (on the A-Class and B-Class) under the passenger compartment, and two batteries used in the Smart easily fit into the A-Class.

Smart ED

Daimler believes that battery-electric technology is ideally suited to small cars, like the Smart ED, but not for vehicles larger than compact size. (Photo by Sebastian Blanco, AutoblogGreen)

What’s your view of Tesla’s battery strategy?

I think it’s a very good solution for now, but Tesla already is working on the next generation, where they will improve the consumer cells in order to better meet automotive requirements. The size will be the same and the capacity will be very similar. I think they have a very sophisticated concept of connecting the cells, and managing the cells—and their battery electronics is a very intelligent and sophisticated system able to control the many thousand cells in their Roadster and our Smart and A-Class. [Note: Later, Dr. Mohrdieck responded to complaints that the Smart ED is underpowered, by pointing to limitations of getting enough power out of the 16 kWh Tesla pack used in the Smart ED.]

So even if other automakers move ahead of the pack in terms of battery technology and electric cars, you think everybody will eventually be in the same place?

Maybe not everybody, but those who are serious about it. Daimler will have the opportunity be there on time.

We had the same story, the same hype, in California in the 1990s, and we all know what happened. This is not saying battery or fuel cell technology is a bad thing to do, but nobody can be faster than the laws of nature. We have to do thorough development, and we will come up with high numbers of cars, but this will take time. People have very high expectations in terms of quality and reliability of the car. There will be an increasing number of battery electric vehicles and fuel cell electric vehicles, but it won’t just jump from zero to 100,000 cars a year.

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