Musings: Hydrogen cars?

This is a supplementary page, for "Hydrogen cars?". It is based on an e-mail exchange with Jakub, who has extensive experience with fuel cells. The exchange is presented here with only minor editing, and no attempt to reach conclusions. It simply presents some things we chose to talk about for a couple days. The three stages in the exchange are distinguished here by indentation.

Hmmm, this is quite interesting.

First of all, they're pulling $100 million/year. Not a big deal, really other than bad press for fuel cells. Bush put that program as a candy to get a couple of extra votes.

One interesting point... Some fuel cells operated for 2000 hours without need for servicing, the equivalent of driving 96,000 km (~60k miles) but govt. wants that number to be 150k miles.

Isn't 60k miles already a major service mileage for the technology that have been on the roads for so long?

Perhaps a good point.

However, that would mean that it is likely it would last that long. I gather that is too optimistic at this point. ??

2000 hour is actually very short for a company with a good technology. Seven of our old technology units (complete systems) reached over 15,000 h and are still running.

Our new technology cells completed over 20,000 h on a single cell test stand (ideal operating comditions) with 0.00% power degradation. If a company right now can't make a system with 5,000 h of operation they won't be able to compete on a current market.

However, those "good" systems still need servicing, which is often non-cell related: water pumps that fail, air blowers, etc.

How do they fail? Do they give warning signs, or do they just suddenly die? Can the warning signs be detected by the car's computer?

Of course there are sudden failures that usually related to membrane damage (puncture, overheat, freeze) in case of PEM, or cells fracture in case of SOFC. I didn't see any of those within my 14 months and a few systems run continuously through all this time.

There're generally two cell-related failure mechanisms:
* loss of catalytic activity: through catalyst poisoning most of the time;
* loss of mechanical integrity: separation of cells in case of PEM and SOFC, or so-called thermal channeling (which is creation of hot channels that prevent even distribution of air or fuel).

In both cases you will see slow degradation of power and yes, car's computer would easily pick it up. When you look at it, these are also the two common engine-related failure modes of current cars:
* loss of catalytic activity: spark plugs;
* loss of mechanical integrity: loss of compression in cylinders due to the worn out piston rings.

In both cases again you see slow degradation and car very often tells you about it.

I don't think that is the weak link for H-FC (hydrogen fuel cells) at this point. I think the lack of H2 is the key problem, with no solution really imminent. ??

Yes, I agree, but then again they're targeting fuel cells instead of H2 production and storage. Both in funding and then cutting it. They made a mistake funding H2 car without first heavily funding H2 technology. They should have first funded H2 research and then if succeeded, fuel cells would find their way into cars.

And then there is the political consideration... They want to be seen as prudent, not just doing everything. So they make some choices. Are they the right choices? Who knows. The article notes that this will be the subject of both sci and polit debate.

The article notes that work on stationary FC will continue. Is this the same type of FC or different? I suspect they are getting some mileage for saying that FC work will continue.

Usually different. Stationary fuel cells currently are Phosphoric Acid (PAFC) manufactured by UTC Power and Molten Carbonate (MCFC) by The FuelCell Energy. Oh yeah... And until very recently SOFC by Siemens. There're some attempts to have PEMs as stationary but they can't really compete.

Return to main part of this story: Hydrogen cars? (June 24, 2009).

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