Good. Hydrogen was just a smoke screen to delay the widespread deployment of hybrids - followed by plug-in hybrids and then ideally followed by 'electric cars'.

even if was successful can you imagine the uproar from the "environmentalists" when it dawns on them that the only thing that comes out of the tailpipe is water. the very thing that really defines greenhouse effect. just a matter of time til they were condemned as the most poluting thing on the planet.

uhhh... Water doesn't define the greenhouse effect... I thought it was CO2

Hi All,

Well, there is no need for a hydrogen highway if one has Natural Gas service. I am not a chemist, but I just think one could combine H2 with recent plant sourced carbon and transport it down a pipeline. Would be a boone to accounting schools. There will be allot of bean counters needed to keep track if the CH4 used in cars is less than that provided by H2 sources, and then charge a big tax when you use fossil sources.

This is a surprise only by the fact that GM didn't wait till 2010 to state as such. They could have had 2 more years of free "we're going to build a Volt" green washing publicity.

Hi Fred,

Water is the anti-greenhouse gas in many ways. Take a look on Google for "Global Dimming" and also watch the Nova episode regarding it.

This is good news. No, great news. I never understood the attraction of hydrogen fuel cells, except as a way to get research money. It's been a farce from day one, and it's about time we can all admit the truth about the Emperor's new clothes.

Same thoughts here. Although a part of me does feel strange feeling glad over GM poo-pooing hybrids. Now that GM is admitting to improved battery technology, lets see some plug-ins and BEVs! (and green electricity too)

My sister worked for two fuel cell companies nuvera and catalytica. She always agreed with me that it was a joke in terms of solving the car problems, but hey, if someone was going to pay for the research...

Wow. I wonder who blinked first!?

I want what he is having.

Water vapor is the most important greenhouse gas, accounting for (say) two-thirds of the atmosphere's greenhouse effect. But it's passive -- it doesn't persist in the atmosphere, and any excess precipitates fairly quickly. It's not an external "forcing" of climate change, in the language of the climate scientists.

The isolated fact that water vapor is the most important greenhouse gas is used to great effect by people who deny the existence of manmade climate change. It's just another one of those factoids that has great, superficial "wow" factor for the uninformed. But except for the cloud formation question, it doesn't much matter. (There is a separate, more serious issue regarding changes in cloud cover increasing the reflectivity of the earth's surface and/or reflecting heat back to the ground, but that's different from the issue of water vapor as a greenhouse gas.)

Basically, 3/4ths of the earth's surface is water that is trying to maintain equilibrium with the atmosphere over it. So any disequibrium (excess) atmospheric water vapor content disappears in a matter of days.

Contrast that to C02, whose atmospheric "half-life" is on the order of centuries, as best as that can be measured. Very much a slow poison. Even now, 300 years after the start of the industrial revolution, the total carbon in the atmosphere is only about one-third higher than it was prior to the industrial revolution, although the rate of growth has accelerated over time. (So, as an obvious corollary, people who talk about the failure of last year's output of C02 to raise this year's temperature just don't have a grasp of the facts. Even now, the rate of growth in atmospheric carbon is well below 1%/year.) But if we ceased all fossil fuel consumption immediately, it would probably be several centuries before atmospheric C02 declined to near that background level. Completely different behavior.

A good reference for anything of this sort is realclimate.org. A discussion of water vapor is given here.

RealClimate


These guys are climate scientists, so if you're looking for a quick explanation, this isn't it, but I think it's readable enough. The key sentence is:

"The overlaps complicate things, but it's clear that water vapour is the single most important absorber (between 36% and 66% of the greenhouse effect), and together with clouds makes up between 66% and 85%..."

Relevant to this thread, cars emit a lot of water vapor now. About a quarter of the weight of current car tailpipe (coal power plant, etc.) emissions is water, as you can tell for the formula for combustion of a hydrocarbon:

C(n)H(2N+2) + (2N+1)*02 = (N+1)*H20 + N*C02.

You get roughly equal numbers of water molecules and C02 molecules, but C02 weighs more.

So a car burning a gallon of gasoline a day produces something like a gallon of water a day. If all the energy came from hydrogen, you might up that to four gallons a day. By contrast, a large-ish tree will transpire something on the order of 100 gallons a day in the summertime. If you're worried about injecting "harmful" water vapor into the atmosphere, you'd be better off chopping down a tree than avoiding hydrogen as a fuel.

Finally, I think the appeal of hydrogen was more for the business model than for the science. Sell people EVs with long-lived batteries and solar cells, and you've just put yourself out of business (if you're in the car or oil business.) So all the industries that were funding the hydrogen research were, imho, funding the solution that would keep them in business. Can't blame them for that. Would not blame them if they continued funding it, on the off chance that the facts may sometime change in their favor. It's not an unreasonable investment, given what they have at stake, and, as noted above, it has advertising value. Same way that I wouldn't blame the Electric Power Research Institute for funding research in the benefits of PHEVs. You just need to have the consumers of that research have enough sense to understand the economic context.

Next we need to kill off the agribusiness subsidy known as corn ethanol. Start by asking your congressanimal to phase out the $0.51 per gallon import duty on fuel ethanol.

Agree with Richard S on the ethanol, but if the loudest voice (agribusiness) gets the worm (subsidies)??? How does one shout down the "goodness" that ethanol brings to farm country? Anti-American not to want "domestic" fuels and all...no matter what the cost overall.

Thanks for the totally educational post chogan2. Hard to argue the H2 debacle is strictly for more big oil control: You want your hydrogen? How 'bout you pay us to convert our product into hydrogen for ya? Plus we'll use a bit of electricity...powerd by our product...and on and on.

I was never convinced that hydrogen was the answer. Everybody seemed to conveniently ignore the elephant in the room:

Where was the hydrogen gonna come from?

It's more efficient to just place electricity straight into a battery than to first convert the electricity to H2 then back to electricity. Finally some sanity. It's a shame Honda spent so much time and effort on their fuel cell technology. Did Toyota also splurge on fuel cells like some auto makers or did they spend their Yen more wisely on PHEV and EV research only?

A professor at my university once said that in research you sometimes have to go down a path all the way before you realize you took the wrong path. Smaller lighter fuel cells will always be in demand by the aero-space industry...

Hydrogen has the potential to scale into heavy duty vehicles like trucks (dump trucks, tractor-trailers, etc) and construction vehicles. I don't believe batteries have that potential.

What would prevent the use of batteries in larger vehicles, even railway locomotives? Why would it be more of an issue than in cars?

I saw a talk about energy by Dr. Nate Lewis, Professor of Chemistry at Caltech, last week and he also said that vehicles are the last place you would use hydrogen as power. Very inefficient. It may be useful in some areas but not as a car fuel.

He also said that it's water neutral as far as the earth goes. It takes water to make it and then reconstitutes back to the essentially the same volume of water.


If you're interested you can get information about his presentation at:
The Lewis Group - Global Energy Perspective

I hope that H2 isn't dead, for the following.
First: people need a way to quickly transport potential energy. It would be great if batteries could hold enough power and be recharged fast enough for this purpose, but they can't. (yet?)

Second: Alternative combustion fuels (ethanol) have a greater environmental impact than oil, as you have to grow the food then convert it to ethanol, has a more detrimental affect on the poor, as in they can't afford food now, and generally STILL has the same tailpipe emission problems.

Third: H2 is a good transport medium for potential energy, of course no where near as good as oil, but given H2's limitless supply in the universe, not to mention we could produce ALL our own H2 instead of depending on foreign suppliers. Of course making H2 is "currently" less efficient than oil or pure battery powered cars (again batteries not practical, yet) like anything else with widespread use and investigation more efficient means of production will be discovered.

Also, environmental impacts could be closely monitored as electricity production facilities provide a point source that is easily monitored, as opposed to millions of tailpipes.

Fourth: Plug-ins not practical either. Granted it sounds good but what the heck would happen to the electrical grid if a million people plugged in a car everyday, now multiply that by a hundred!!! The grid would collapse, or it would take such a massive increase in power transmission potential and generation that again the benefit of the plug-in would be lost. Granted on a small scale it has an effect and feels good, but ANY potential alternative has to ultimately be weighed on its viability for widespread use.

Fifth: Please don't tell me there is no infrastructure to transport H2, it could be developed and implemented nationally in less than 5 years if that outcome was so desired.

Summary: The only real negative to H2 is its production drop in efficiency compared to pure electrical transmission to a battery. The development of both would be the best result, a quick charging battery that can go 100 miles on a 5 minute charge and a reserve tank of H2 (to power a combustion generator or fuel cell if they can be made cheaper) for additional travel extension.