Thursday, March 03, 2005

Hydrogen Distortion
It's unusual to run across an article that cites a long list of references yet contains an equally long list of errors of fact--or at least of connecting unrelated facts in a way that renders them erroneous. I just received one from a newsletter called EnergyPulse. The title was intriguing, "The Hydrogen Economy - Energy and Economic Black Hole," by Alice Friedemann. This article illustrates how rapidly we've gone from a general view of hydrogen as a perpetual-motion energy nirvana, to a realistic understanding of hydrogen as an energy carrier--not a source--and onward to a growing body of criticism seeing hydrogen as, in Ms. Friedemann's words, "an energy sink." This is a step too far, at least at this early stage.

Now, I certainly agree that you need a good reason for turning some other form of useful energy, be it natural gas, coal or electricity, into hydrogen, because of the energy losses inherent in any conversion process. But this categorically does not mean that sufficiently good reasons don't exist. In the case of the fuel cell cars and trucks currently under development, that reason is the high thermal efficiency of the fuel cell itself, which has the potential to more than compensate for lower efficiencies in other parts of its energy chain.

The fair and objective way to compare efficiencies is on a "well-to-wheels" basis that looks at the entire system of fuel delivery, conversion processes, and vehicle. This analysis looks at the original energy content of the fuel and the amount consumed in every step along the way, enabling direct comparison of a wide variety of energy systems. You can, for instance, compare the efficiency of a hybrid car running on gasoline refined from oil pumped in Kuwait and transported to the US by tanker versus a fuel cell car running on hydrogen extracted from natural gas produced in Louisiana and transported by pipeline to a chemical plant. A number of independent groups have done this for a variety of fuel and vehicle combinations, and the results are available on the internet.

Unfortunately, Ms. Friedemann seems to have selectively chosen the worst news from each separate step and created her own "woe-to-wheels" analysis. For example, she strings together the "efficiency" of a wind turbine with that of hydrogen generated by electrolysis to demonstrate how much energy is lost making hydrogen to run a car. But if the lost wind energy was never available to us in any other form, the whole concept of efficiency becomes meaningless, and the correct multiplier is 1, not 1/3. The article includes at least sixteen other errors of fact or interpretation, or suppositions stated as facts.

While I don't mean to belittle someone who apparently did a lot of research before writing a freelance article, I believe it is important to debunk this kind of pseudo-science, just as it is important to disabuse the public of the notion that hydrogen from the sky will solve all our energy problems. Hydrogen is no one's free lunch, but neither is it a pointless boondoggle. Instead, it is a promising potential pathway for introducing non-fossil-fuel energy into transportation modes currently dominated by petroleum products. It will take years and much effort before this pans out, if it ever does, but it is entirely premature to write it off today.

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