H2, or not H2: That is the question

[unixronin]

radarrider found this article on hydrogen-fueled cars, which led me to the following response:

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I hate the common misrepresentation of hydrogen as an "clean, non-polluting energy source".  It isn't.

Sure, it burns cleanly, producing nothing but water vapor when burned in pure oxygen.  But it's not an energy source, it's an energy storage medium, and not a highly efficient one -- it takes around 20% more energy overall to produce hydrogen than you get back by burning that same hydrogen even in a fuel cell, let alone an internal-combustion engine.  Neither is it non-polluting; it merely relocates the pollution to the generation site of the power you use to produce the hydrogen.  It sweeps it under the rug, so to speak, and then you hope no-one notices and wonders why that particular patch of the rug is sorta lumpy.  And storage is a major headache; either you need a pressurized tank refrigerated to cryogenic temperatures to keep your hydrogen liquid, or you need a metal-hydride absorbtion tank that requires a heater to release the hydrogen.  Either way, still more energy loss.  (Room-temperature storage of pressurized hydrogen gas, to the best of my knowledge, has been written off as infeasible; I saw an analysis of a proposed bus fuelled by gaseous hydrogen, and the analysis pointed out that to give the bus sufficient range to make it commercially operable, it'd have to have a hydrogen tank as big as the bus.)

To get an idea of the realism of this idea, you need look no further than the numbers.  "It is time for the people to make a move, the vehicles they say they want to run on hydrogen are available now," says Tai Robinson.  Yeah, sure.  How many of "the people" can afford to spend $150,000 on their next vehicle?  Especially when they can then, to all practical purposes, only drive that vehicle in California -- and be restricted to a few California cities at that, and pay up to $20 per kilo of fuel for the privilege?  Come on, guys, you CANNOT be serious.  No-one's going to be taking that two-week camping vacation in the Sierras driving a vehicle with an unrefuelled range of 80 miles.

Sooner or later, we have to move away from the IC engine.  That's pretty much a given.  Unfortunately, we don't have a better solution yet.  In the meantime, there's a lot that can be done to reduce pollution and fuel use.  Stratified-charge engines, for instance; or direct-injection turbodiesels, which are increasingly popular in Europe but have never made a big impression on the US market because -- frankly -- Detroit can't build a decent diesel engine to save its life.  No, not even Cummins.  You want to learn how to build automotive diesels, ask, say, Mercedes-Benz.  Diesel exhaust can be cleaned, too, if you have low-sulfur fuel.  Europe has it.  US oil companies complain about the refining cost.

My guess is that in the longer term, we'll actually be moving to electric vehicles, and they'll probably be powered by fuel cells.  But the fuel cells probably won't be burning hydrogen.  Sure, hydrogen is sexy, hydrogen is modern, hydrogen is so 21st-century .... it's also a bastard to work with.  However, with a suitable reformer, you can just as well run a fuel cell on methanol or ethanol, both of which can be refined cheaply and easily from vegetable sources as biofuels, and both of which are much easier to store than hydrogen.  You can even modify an IC engine to run on ethanol or methanol in the meantime -- and you can push compression ratios to the stratosphere, because alcohol-fueled IC engines don't suffer from detonation like gasoline-fueled ones do.  Drag racers burning pure nitromethane run compression ratios as high as 20:1 -- that's diesel territory.  Bio-alcohols are renewable, and they aren't net producers of greenhouse gases because what you produce burning one batch, you consume again growing the feedstock for the next batch.

The unfortunate truth of most of this, though, is that ultimately what you can buy in the showroom is not driven by what's the best technology available, nor by what does least harm to the environment, but by what makes the most money in Houston and Detroit.  This will not change significantly as long as our government is in the pocket of industry, and specifically the oil companies.

Comments

[juuro.livejournal.com]

And when does it start hurting? Ten years ago I heard people make loud noises about "when gas costs XX per litre, I'm not driving any more."

We have crossed that threshold years ago. And guess what: those people still drive. The same cars, the same income.

(Both gas cost and income inflation-corrected in this comparison.)

[skellington.livejournal.com]

I suspect the prices are roughly where they are in Europe. People there DO buy diesels. They have small cars, and cars with small engines. Even delivery trucks have as small of an engine as feasible.

Sure, some people will still buy a Hummer. But it will make most people notice.