
The Cadillac Provoq is GM’s latest E-Flex concept car, a luxury crossover with all wheel drive and fuel cell range-extender. Nick Zielinski who used to be the ICE Volt’s chief engineer is now the chief engineer of the hydrogen Volt and Provoq, as well as the fuel cell Equinox. I had a few moments to speak with Nick at the Provoq Detroit unveiling (see post).
What brought about the Provoq design?
We’ve been intrigued with trying doing something with Cadillac, its our high line vehicle, our technology leader, taking our most advanced technology propulsion system and marrying that with Cadillac made a lot of sense.
When you figure fuel cells as we introduce them are going to be low volume and they’re going to be more expensive than traditional propulsion systems. So it made sense from a marketing standpoint to link up with a high line vehicle. It was just a nice marriage between the image of Cadillac and the technology of our most advanced propulsion system. So my role in that one was around the propulsion system of E-flex, since I’m doing the E-Flex fuel cell off the Chevy Volt, we also did the Provoq.
Are you actually in the production pipeline, moving towards a hydrogen fuel cell Volt?
Were working on an E-Flex version of the fuel cell as opposed to the generator set, and were working in the same way were working the regular E-Flex for the Volt. We are moving towards production. We are not making any commitments on production timing. We’ve got a number of issues. We are working on our fifth generation fuel cell stack. Similar to the battery, the readiness of that fuel cell is going to take whether we introduce it and when we introduce it.
Is the fifth generation lighter or smaller or more efficient that the fourth generation?
There are a number of drivers. One of the big things we are doing for the fifth generation is physically making the stack part of it smaller. In our Equinox program the fuel cell stack is pretty tall and what we want to do is get that system smaller. That way we can pack it into a broader range of vehicles. Because of the height of the current stack there were some limitations on the vehicles you could put them into. So the next generation will have much broader application, also some new technologies to address durability which is an issue we continue to need to work on in our fuel cell systems.
What do you mean by durability? Are they fragile and not handle road vibrations well?
No. Thats not really an issue. The way a fuel cell works is they like to be what we call a steady-state device. They like to produce power at a certain operating level and stay that way. A car is a dynamic device. You have to increase the amount and oxygen and hydrogen to get more voltage to make a car accelerate. What happens in a fuel cell is those transients take a little bit of the life out of the stack. So we have to make sure we understand the materials and the chemistries and the membrane that does the conversion to electricity. Things like starting it and stopping it affect that durability. So a lot of work to pull all that stuff together.