Fuel Cells are No Panacea – and By the Way, Those Pesky Environmentalists

Dear Editor:
I am a co-author of a paper to be presented at the upcoming Asilomar conference of the Society of Naval Architects and Marine Engineers, which, among other things, proposes hydrogen fuel for ferries. I was therefore interested in the fuel cell ferry for Treasure Island, and regard it as a valuable project to evaluate the feasibility of a portion of possible future technology.

However, it is important to the whole story when discussing science involving public policy, and readers of Bay Crossing should be aware that fuel cells alone are not a panacea for environmental issues.

Many practical fuel cells use either hydrocarbon or even carbon based fuels (coal) and generate hydrogen by liberating the hydrogen content from the hydrocarbon fuel, and/or using the carbon to take up oxygen from water, thereby releasing hydrogen. In most cases this is accomplished with a “reformer” external to the fuel cell, though some new technologies (MTU’s “Hot Cell” system, for example) reform within the fuel cell itself. Though is true that the fuel cell only uses hydrogen and only emits water vapor, the reformer emits carbon dioxide and in some cases requires added feed material to take up sulfur and other contaminants in the fuel. Though this latter material doesn’t go into the air, it still is a waste stream. Fuel cell systems may have much lower emissions than internal combustion engines, but they are not really zero emissions unless they are actually fueled with hydrogen. (To be precise, fuel cells running on hydrazine, N2H4, or ammonia, NH4, only emit water vapor and nitrogen gas. Hydrazine fuel cells have been built, mainly for spacecraft, but hydrazine is not a friendly material. Ammonia fuels cells have not yet been even shown to be practical.)

Leaving aside the practical issues of storing large quantities of gas fuels, it is possible to produce hydrogen and oxygen from water, (in fact, technology related to modern fuel cells makes this process considerably more efficient) but this requires energy, which must come from some other source.

In developing rational public policy for energy use, this question has to be answered in detail, including evaluation of costs of these technologies and their environmental impact. Just discussing renewable energy sources is not sufficient. This is not meant to condemn hydrogen, but a complete discussion ultimately requires a complete analysis, and almost certainly detailed and innovative approaches. Just like money, using hydrogen is easy, getting it is hard.
Finally, as regards the need for accurate science, Bluewater Network representatives keep bringing up their report condemning conventionally fuelled ferries as significantly more polluting than autos. This report has been shown to be seriously flawed. Though it is fashionable these days to deconstruct truth as being dependent on point of view, it is possible to do engineering analyses accurately and such a review of the Bluewater report shows that its conclusions are basically backwards, and hence are a poor guide for public policy. To offer a classic parable, the report is a dead parrot, and if the Bluewater advocates did not keep nailing its feet to the perch, it would be pushing up daisies. Flawed science does not serve the environment, and perhaps worse, damages the credibility of the Bluewater Network on other issues.
Christopher D. Barry, P.E.
Baltimore MD

Those Pesky Environments, Con’t:

Dear Editor:
Re: your headline, “Those Pesky Environmentalists” over my comments regarding Port Sonoma, may I say that pesky headline writers are the bane of a reporter’s life!
Other than that quite an impressive 40-page tabloid in April, and especially interesting for those of us who have lived in San Francisco as well as New York. I even ran onto a full-page ad for Bahr’s Landing, an old hang out of mine on the Jersey Shore. Many’s the great shore dinners we’ve had there!  Try it sometime; it’s great!
Wes Starratt
San Rafael

New York from New Jersey