Nature has picked up a paper(pdf) by the Oswald brothers published in the journal Accountancy.
I can't recall the blog I first read describing the paper but it looked fishy enough to write and protest that the numbers weren't right. Jim Oswald did respond and his response made it very clear that whatever they were talking about, they were not talking about the hydrogen economy as most people conceive of it.
1. The calculations are for hydrogen burned in internal combustion engines (ICE), not hydrogen fuel cells. Virtually everybody views the hydrogen economy as a fuel cell economy with hydrogen run through the cells to directly create electricity, not burnt in cylinders that drive pistons, that turn a wheel or drive a generator.
2. Like all other ICE type motors, hydrogen ICE are limited in efficiency as they are Carnot heat engines. At realistic temperatures, fuel cells can have 3x the efficiency of ICE. This means that even with hydrocarbon created hydrogen, you lower pollution with hydrogen as everybody except the Oswalds in this scenario look at it.
3. The Oswalds deliberately and artificially narrowed the available sources of hydrogen to nonpolluting sources that are commercially viable today with no technological progress allowed for, nor any thought to how rising petroleum costs would make other sources of hydrogen become viable as energy prices rose.
4. Energy is lost in transportation with the shorter you go, the less you lose. Hydrogen is likely, on average (and certainly for the US & UK) to be produced closer to home than our current oil supplies. This effect is unaccounted for.
When all the constraints and fudges are made explicit and clear, the Oswalds' paper is a somewhat useful teaching tool to drive home the point that a totally clean hydrogen economy is going to be hard work. But that's not how Nature interpreted it and it's not how most people will read it who know nothing but the buzzwords of a "hydrogen economy". While the Oswalds are honest enough to freely admit their constraints when asked, they're not doing their duty to the truth in bludgeoning even science journalists to get the story right about the narrowness of their actual claims.
Posted by TMLutas at October 18, 2004 05:04 PM