General Motors, once a very public leader in the move to develop hydrogen fuel cells for transportation use, has been pretty quiet on the subject for the past decade.
Recently though, GM announced a joint venture with Honda to build a fuel cell manufacturing plant, and, with the U.S. Army, has begun testing a military vehicle, the ZH2, that’s based on a heavily modified, fuel cell powered Chevrolet Colorado midsize pickup. GM has invested at least $2.5 billion in the technology in just the past two decades.
Charles Freese, GM’s global head of fuel cell development, sat down with Trucks.com recently to discuss the automaker’s approach — he calls it a land-sea-air technology — and what the future might hold for fuel cells. Here is an edited version of the conversation:
You’ve developed the Chevrolet ZH2 military fuel cell truck, but you don’t have a civilian vehicle. Why?
We haven’t announced a vehicle program yet, but we have announced that we are building the plant to build the propulsion systems that will be used by vehicles from both Honda and GM. The ZH2 program is an opportunity to get synergy from something both we and the military are interested in.
We wanted with the ZH2 to evaluate how the technology performs in a true off-road vehicle, a pickup truck with extreme capabilities, and we’re trying to leverage what fuel cells offer that other technologies are not as well-equipped to offer.
We have a big vehicle with 300-400 miles of range, and we can also offer twice the efficiency of an internal combustion engine with all the torque needed for four-wheel drive and rock-crawling.
We’ve got approach and departure angles that are better than a Humvee.
We had people up on hillside one night, waiting for the ZH2 so they could take pictures of it, and they couldn’t hear it coming. That ability to have stealthy operation and a low thermal signature, which we deliver with a fuel cell electric drive system, is very desirable for the military. They don’t want to be detected.
And then add to that the ability to export 25 to 50 kiloWatts of power [from the fuel cell], which could run a field hospital, or a laser targeting system, even a high-energy weapon. And you don’t need a big Humvee towing a diesel generator, which is bulky and very noisy. And then the fuel cell produces water, which is very valuable in battlefield conditions.
And hydrogen is just a way to store energy, so you can make it from whatever is in the field, from wind, solar, jet fuel, natural gas, any petroleum source.
Will what you learn help with non-military uses?
If you design the right fuel cell system, it can be relatively modular. It gives us a system that can be sized for various types of vehicles. It opens a lot of opportunities for us in what we’re calling the land-sea-air approach.
Yes. We can start to use exactly the same fuel cell system that’s in the ZH2 and scale it for other vehicles. We’ve got more than 1,000 hours in a Navy unmanned undersea vehicle. It’s just different mission parameters.
Where do you see the first full-scale commercialization? Consumer? Military? Commercial?
I can’t possibly tell you. But all have a lot of promise, and they gain from each other. As the automotive technology develops further and we continue to bring costs down, that helps in aircraft application, that helps with forklift application. If I add scale by using it in military or commercial applications, that brings the cost down for automotive.
So, the answer should be “all of the above”?
The advantage of the fuel cell is its scalability and flexibility for a wide range of applications.
We can stack fuel cell systems, reusing the investment that’s been made.
I can use one full stack, say, under the hood of a passenger vehicle, a third of a stack in a forklift, and I can put two stacks side by side and get into some bigger truck applications.
That’s land, and you mentioned your work with the Navy. What about the “air” part of land-sea-air?
Aerospace gets to be really interesting. With an aircraft, you’ve systems for fire suppression in the cargo hold, you’ve got a system to store and pump nitrogen into the fuel tanks in the wings to make them inert as you empty them, you’ve got an emergency backup power system. You’ve got water tanks for the toilets. These are all separate, heavy, expensive and take up a lot of space on the aircraft. With fuel cells you can start to think about integrating all of these into single systems.
One alternative to halogen fire suppression is fuel cell exhaust, so now I’ve made my fire suppression system on the aircraft. And I can use power from the fuel cell to run my galley and for the lights, or for backup power, and I can also take the humidification out of the exhaust and use that water to flush the toilets.
I can even distribute smaller fuel cells up and down the aircraft for localized power and take miles of wire out of the airframe.
Talk a bit about the GM-Honda partnership. Is there a division of labor or is it completely integrated?
GM is No. 1 with intellectual property in the fuel cell space, Honda is No. 2. Together we’ve got an overwhelmingly strong patent and intellectual property portfolio. GM was already on Generation 2 of its fuel cell, Honda was tooling up for its Gen 1 system [with the Honda Clarity fuel cell sedan that went on sale in California this year] and has some practical launch experience that was very advantageous. Couple that with GM’s experience and it was just a case of 1 plus 1 makes 5.
We both threw in all of our intellectual property; we fully integrated the development teams. It’s a co-development program. Both companies working as one.
Where are you on cost reduction?
It is orders of magnitude down.
As we went from Generation Zero to Gen 1 we were able to take half the mass out of the system, and the platinum level for the catalyst went from 80 grams fuel cell to 27 grams. And platinum was one of the major cost items.
In Generation 2 it’s down in the 12-gram range. And we are testing even lower than that now.
Our Gen Zero fuel cell had five hydrogen injectors and two stacks with 440 cells combined, and we had a flow shifting system to manage the injectors between the two stacks. Now we’re down to two injectors, a single stack with 304 cells, no flow shifting. It’s much thinner because we’ve gone from difficult-to-manufacture composite cells to stamped metal cells, like stamping head gaskets.
We’ve integrated more of the manifolds and other gas, water and fuel handling systems into this design, so we don’t have to have as many tubes and valves things like that bolted on; we’ve also eliminated many sensors.
Are you anywhere near what you’d consider being commercially viable, cost-wise?
Well, we’re at a point where we’re willing to commercialize the design, that’s all I can say.