Update on the GM-Honda collaboration on Gen 2 Fuel Cell Propulsion System
17 February 2015
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| Overview and partitioning of the GM-Honda collaboration on fuel cell propulsion. Click to enlarge. |
Over the past two years, GM and Honda have been collaborating on next-generation fuel cell and hydrogen storage systems, aiming at commercialization in the 2020 time frame. (Earlier post.) At the SAE 2015 Hybrid & Electric Vehicle Technologies Symposium in Los Angeles last week, Andrew Bosco, Chief Engineer for fuel cell engineering at GM, provided an progress update on the joint Gen 2 Fuel Cell Propulsion System. (At the SAE 2014 Hybrid & Electric Vehicle Technologies Symposium, Mark Mathias, Director, Fuel Cell R&D for GM, had also provided an update on the collaboration. Earlier post.)
As the two companies have emphasized from the beginning, Bosco reinforced that the current scope of the collaboration focuses on reducing the high cost of fuel cell specific systems: i.e., the fuel cell stack; balance of plant components; and hydrogen storage system (HSS). Development on the battery (regenerative ESS), fuel cell power electronics (FCPE); and electric traction system (ETS) is leveraging know-how and components from hybrids and battery-electric vehicle work.
The two companies are working as “one team” across 3 countries—Japan, US and Germany—Bosco said. The focus is one common system with jointly agreed core and technical targets, capable of 2020 production.
In reviewing the context for the push on fuel cells, Bosco noted that fuel cell electric vehicles, with the travel provision, are the most effective generators of ZEV credits in California and the nine other states that have adopted the California ZEV regulations. FCEVs (350-mile) earn 4 credits in the 2018 and beyond timeframe vs. 1.5 credits for a 100-mile BEV.
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| The focus on the GM-Honda work is on reducing costs. For one example, the joint team is targeting a reduction in platinum loading to about 11g Platinum, down from 80g in the Equinox fuel cell. (Earlier post.) Click to enlarge. |
A Pareto analysis of cost shows that many of the expensive parts of the fuel cell system are not entirely unique to fuel cells, Bosco said. The team has reduced the amount of previous metal catalyst required significantly, from 80 g in the Equinox Fuel Cell Vehicle to around 11g in the Gen 2 system. This cost element is no longer a commercial barrier, Bosco said.
On the storage system side, however, the Pareto analysis shows that fiber cost is a major element.
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| Fuel cell system cost Pareto. Click to enlarge. | Hydrogen storage system cost Pareto. Click to enlarge. |
One of the examples Bosco touched upon as an example for cost reduction was the bipolar plates themselves in the stack.
Even at low vehicle production volumes, the bipolar plate is a high volume part.
—Andrew Bosco
At 300 cells per vehicle, a mere 1,000 vehicles would require 300,000 plates; at 10,000, 3 million, and so on. Global auto production in 2014 was 86.5 million units.
The Gen 1 plates are stamped stainless steel; their cost is sensitive to the price of nickel. The goal is to move away from austenitic stainless steels to ferritic stainless steels, which have low/no nickel. On the plus side, ferritics are magnetic, leading to easier handling. On the downside, formability is a technical challenge.
Overall, Bosco noted, the automotive industry has “extensive cost reduction experience”; suppliers will play a major role in cost reduction opportunities. The partners are looking to deploy the Gen 2 fuel cell technology “early next decade if things keep going the way they are going.”
I'm not too terribly convinced on this iteration, the hours are pretty low, but I would like to know what the service life really is... Like is it still operable, but at a diminished rate? Or does it simply have a major fault and cease working?
If a diminished rate, is the PEM still economically effective? meaning does it still use the same amount of joules per mile, just at a slower output?
Posted by: CheeseEater88 | 17 February 2015 at 08:08 AM
@CheeseEater88 FC lifetime is rated similar to that of a BEV, that is, end-of-life is at ~70-80% of rated power. Efficiency may also decrease, but it's generally the power loss that defines the lifespan.
Used automotive FC's would be perfect for low-power whole-house generators running off of reformed natural gas.
Posted by: David Freeman | 17 February 2015 at 01:06 PM
I'm surprised to see the HSS still so expensive. I think CARB is really skewing the market with their HFC credits. Replace the expensive HSS with a regular fuel tank and an on-board multi-fuel reformer. No problems with finding a fuel station.
The use of standard, low-temperature FC's, does, of course, require dry clean hydrogen, whereas reformed fuels may introduce contaminants (sulfur, CO, H2O) that poison the FC.
GM should instead transition to a high-temperature (150-250C) FC design that would greatly simplify the FC BOP. For example, CO poisoning won't be a problem, and simple fuels (methane, ammonia) can be reformed directly in the cell. No more complex liquid cooling, since everything can be air-cooled. Higher temperatures increase catalysis activity, reducing (or removing) the need for platinum.
Posted by: David Freeman | 17 February 2015 at 01:14 PM
I know the PEMs nominal voltage decreases, but if the PEM still functions correctly(doesn't loose noticeable efficiency), I wouldn't necessarily limit the service life of the vehicle to 150K miles. Most will reside in a PHEV, so there probably won't be that large of a demand of power over time especially if it a large battery pack.(just runs longer at a lower output to make up for the lack of power)
Just for reference most manufactures build for 10 years 150K miles... ICE, PHEVs and HEVs...(I do think that some BEVs are much lower than this 150K life) this could still be a design target, not a expectation. What they want is a minimum... Lately that minimum has been shifting in the publics hand, cars are indeed much better than their predecessors. Oils and other factors do play a huge part too.
Carbon fiber tanks, being a huge cost, should come down quite rapidly, CF is being used for tons of applications and as it become mainstream we should see it dropping in price as production of the material ramps up.
The future is going to be interesting... are we going to have $30K midsized cars with BEVs or HFCs?
Sadly both need lots of infrastructure... I am pushing for a plugin fuel cell SUV with 50miles electric range or more, capable of driving at least 300 miles off of H2.
I think that it would keep the battery down to an affordable size, and would allow for great distances to be covered more.
I wouldn't want a BEV with 500miles range and not be able to charge it quickly at home/ on the road. I wish that we had DC voltage to our homes in the US, so many things could be made better by this...BEVs would have a lot less adoption problems
Posted by: CheeseEater88 | 17 February 2015 at 08:02 PM
CE, would you really need fast charge at home if you had 500 mi of range?
I can't imagine a scenario where I'd drive 500 miles, return home, and need another 500 mile range in short order.
As the owner of a 265 mile range BEV, I find I charge much less frequently, and at lower speeds (often 120v) than I do with my 76-92 mile BEVs.
Posted by: electric-car-insider.com | 18 February 2015 at 07:30 AM
I do a bit of traveling, it would be nice to have a 50+kw charger in the home. I used to live in a place for three years where the closest walmart/movie theater/substantial town/hospital was almost two hours away. To have a situation where I needed to travel and not have the means would be rather frustrating, it is the the reason we have personable mobility. There are days where I would drive over 200 miles, shuttling people around, shopping and just taking care of things. (in a large city)
In the middle of nowhere bare minimum was at least 180 every time you set out, if you had to make that trip twice in one day, it may not work out.
I dont have the wherewithal to own more than one vehicle... It would be nice to have the option to own a Bev and charge at home no matter where I choose to live... I see the benefits its just not in anyway tangible for me, and that is a bit upsetting. I live in an apartment now, there is no means for me to charge, I haven't even seen a public charge within walking distance of my apt (I'll walk up to about two miles if I can to avoid driving) Or any where I might spend time.
Posted by: CheeseEater88 | 18 February 2015 at 05:17 PM
In California, it's prohibited that landlords not allow tenants to install EV chargers. Soon enough, they'll see it as an amenity and provide them (or lose tenants).
265 miles is a lot to drive in one day. One 45 minute charge doubles that. Really rare that the mid-trip charge would be at home. Much more likely to be at the store or theater or services that you're visiting would be the place you'd charge.
The model for EV fueling is overnight while you sleep. Just a matter of making sure infrastructure for charging is as common as indoor plumbing, electric lighting (including street lamps) or parking meters. EVSE installs are generally easier than any of that.
Posted by: electric-car-insider.com | 19 February 2015 at 08:41 PM
Looking at the "Fuel Cell System Cost Pareto-"
11 grams of platinum costs ~$411 today. And the platinum line is about 3.3 units long. So that would mean one unit is ~$123.
Adding up the lines, we have about 52 parts. That would put total cost at ~$6,400. (Very roughly)
If that includes the motor, controller, and gearbox as pictured, GM and Honda's ~2020 offering would be light-years ahead of Toyota and Hyundai's current FCEVs.
Posted by: David Levesque | 20 February 2015 at 08:42 AM