Hydrogen fuel dangerous?

[George_Bonanza]

I read that hydrogen fueled cars will hurt the ozone. Is this true? Or is it true that H-fueled cars will only emit water vapour?

[Another Bill C.]

1. The product of hydrogen combustion

is water. Check out hydrogen at http://www.hydrogenus.com/

[HereSince1628]

26. If Hydrogen is a fuel in an internal combustion engine wouldnt it use air

as the source of oxygen? And at high temperature and pressure wouldn't some of that atmospheric nitrogen be oxidized? I think that auto exhaust was linked to acid rain problem in the southeat because of nitrous oxides. I also wonder about the possibility of the production of ozone if air is the oxygen source?

[Waistdeep]

28. But we're not talking about internal combustion

A fuel cell + electric motor is far more efficient in converting hydrogen + oxygen to mechanical energy + water than an internal combustion engine. Hydrogen powered cars will all have fuel cells.

Think of a hydrogen car as a hybrid car, but with the gas tank and gasoline engine/generator removed and replaced with a hydrogen tank and a fuel cell.

[Deja Q]

2. The danger is that it's quite flammable in the presence of oxygen

Still, nobody's perfect.

Just be careful where you smoke. :D

Given the abundance of hydrogen, it's amazing nobody has thought of better ways to make use of it.

[tridim]

4. I've heard that the tanks

in H cars are much less likely to explode and burn than gasoline. I think this is because the hydrogen disperses and burns away very quickly, like the Hindenburg. Hydrogen really is the perfect fuel.

[Waistdeep]

9. That's true

I've seen a film of a car with a ignited punctured pressurized hydrogen tank which had a flame rising straight up (since the hydrogen is extremely buoyant). The temperature of the passenger compartment only increased by 1 or 2 degrees celsius. A comparable accident with a gasoline tank would cause complete destruction of the automobile.

[punpirate]

40. This is true... but with a cost.

The fuel value of hydrogen is actually quite low, so storage space is critical.

The picture you saw is of a tank filled with lithium hydride. Under pressure, hydrogen can be forced into the crystal lattice of that material, and the lithium hydride releases it slowly. Rather safe. The down side is that the lithium hydride takes up space in the tank, further reducing the amount of hydrogen that can be stored.

Fill the tank with just hydrogen to gain more space, put a 30-06 round through it and it explodes. Hydrogen is very, very reactive (that's why we have so much water on the earth). Hydrogen combines with oxygen very readily (means it burns nearly spontaneously). You can mix hydrogen and air and set it off with nothing more than a pressure wave in the atmosphere.

Now, the real question is where the hydrogen is going to come from? The only large sources of hydrogen are water and the atmosphere. You can electrolyze it from water, or you can liquefy from the atmosphere. Both processes require electricity.

Where does that electricity come from? Ask yourself why there's so much money in the Bush energy bill for new nuclear power plants....

Cheers.

[dflprincess]

20. Nightline did a show on hydorgen fuel a few weeks ago

They pointed out what actually made the Hindenburg burn the way it did was the the canvas covering the structure was covered with a highly flammable lacquer.

[RandomUser]

14. Hydrogen fires are not as dangerous

as most people believe. Since it's lighter than air, it will float upwards and away from you. The classic example is the Hindenburg(sp?) Airship. The blimp's demise was not so much caused by the hydrogen as it was by the wooden frame. The hydrogen rose to the top and the fire stayed up there, away from the civilians.

[BiggJawn]

33. Hindenburg had an aluminium frame...

Braced with steel wire. Covered with fabric (Linen? Cotton?)finished with nitrocelulose lacquer.
The gas cells were made of fabric coated with a "gelatin solution" to make them gas-tight.

An Ex-NASA engineer named Bain thinks the doped fabric caused most of the fire, not the gas.

[RandomUser]

48. Thanks for the correction

You're right, I was thinking of the canvas frame draping.

[Lisa]

29. gasoline's flammable too ...

And hydrogen will dissipate faster than gasoline vapours ... plus it's not toxic, the way they are. There are a bunch of nasty compounds in gasoline.

We have a hydrogen generator in our lab. One day it malfunctioned and caught fire. Extinguishing it was no problem -- we were back in business a couple of hours later.

Our supervisor commented that if we'd had a similar incident with hydrocarbons, it would have been a heck of a lot messier (in terms of the cleanup, and the possibility of one of us being killed or injured!).

[Waistdeep]

3. An excellent reference

Twenty Hydrogen Myths

added on edit:
Written by Amory Lovins of the Rocky Mountain institute. Well reasoned --- with a very solid science and engineering analysis.

See myths #2 and #14

Myth #1. A whole hydrogen industry would need to be developed from scratch
Myth #2. Hydrogen is too dangerous, explosive, or volatile for common use as a fuel
Myth #3. Making hydrogen uses more energy than it yields, so it s prohibitively inefficient
Myth #4. Delivering hydrogen to users would consume most of the energy it contains.
Myth #5. Hydrogen can t be distributed in existing pipelines, requiring costly new ones.
Myth #6. We don t have practical ways to run cars on gaseous hydrogen, so cars must continue to use liquid fuels
Myth #7. We lack a safe and affordable way to store hydrogen in cars. 16 Box 2: An example of a hydrogen-ready concept car
Myth #8. Compressing hydrogen for automotive storage tanks takes too much energy
Myth #9. Hydrogen is too expensive to compete with gasoline.
Myth #10. We'd need to lace the country with ubiquitous hydrogen production, distribution, and delivery infrastructure before we could sell the first hydrogen car, but that s impractical and far too costly probably hundreds of billions of dollars
Myth #11. Manufacturing enough hydrogen to run a car fleet is a gargantuan and hugely expensive task.
Myth #12. Since renewables are currently too costly, hydrogen would have to be made from fossil fuels or nuclear energy.
Myth #13. Incumbent industries (e.g., oil and car companies) actually oppose hydrogen as a competitive threat, so their hydrogen development efforts are mere window-dressing.
Myth #14. A large-scale hydrogen economy would harm the Earth s climate, water balance, or atmospheric chemistry.
Myth #15. There are more attractive ways to provide sustainable mobility than adopting hydrogen.
Myth #16. Because the U.S. car fleet takes roughly 14 years to turn over, little can be done to change car technology in the short term. Myth #17. A viable hydrogen transition would take 30 50 years or more to complete, and hardly anything worthwhile could be done sooner than 20 years.
Myth #18. The hydrogen transition requires a big (say, $100 300 billion) Federal crash program, on the lines of the Apollo Program or the Manhattan Project.
Myth #19. A crash program to switch to hydrogen is the only realistic way to get off oil.
Myth #20. The Bush Administration's hydrogen program is just a smokescreen to stall adoption of the hybrid-electric and other efficient car designs available now, and wraps fossil and nuclear energy in a green disguise.

[George_Bonanza]

6. Thanks a heap!

Very long, but very informative. Hydrogen all the way! John Kerry's new Manhattan Project is possible!

[karlschneider]

5. Yes, water is the main combustion product, although there will be small

amounts of other oxides. It is no more dangerous than gasoline.
;-)

[papau]

7. It i in the production of hydrogen that the environment is hurt - maybe

The Bush approach is to use oil/coal/gas to produce the hydrogen - not good.

I have not seen a design that yields commercial quanity without being net - system wise - worse than our current oil/gas/coal sytems.

In theory if we harness solar to produce the gas we win - likewise reduction of waste to oil can be a winner.

The Clinton/Gore intermediate step - the hybrid with the changes found since Clinton started the research in 93 - is found in the Union of Concerned Scientists car design - that yield a Ford Explorer
with 36 mph running on just gas - and perhaps 50 mpg as a hybred.

The sedan version topped out at 80 mph. But while there is no new design problem - the part are jusy current off the shelf stuff -there was a 10% initial cost increase in needed sales price (easily made up by gas saving) - and there seems to be no desire in Detroit to produce now that the GOP and Bush are in control.

[wuushew]

10. By using ethanol feedstock from hemp the hydrogen economy could work.

Hemp provides 8 times the energy per acre than corn, combined with advances in fuel cell technology the hydrogen ecomony is coming. I really don't want to see our sources of hydrogen come from steam cracking of natural gas. Natural gas should be used for home heating only. We are drilling like crazy and still have had major price shocks in recent years. The Europeans are developing wind and tidal power and we would be wise to follow their lead.

[papau]

12. I agree - but when does a corporation move on this?

It seems only oil/gas/coal based hydrogen is getting any word play.

[RandomUser]

19. Hemp for hydrogen source

You can use Hemp for your hydrogen source instead of natural gas. But you will still need energy to manufacture hydrogen from the hemp, unless I'm misunderstanding. Thus, the need for an energy source has not been solved. Hydrogen fuel cells are not really an energy source, but rather an energy storage mechanism. The energy still needs to come from somewhere external to the Hemp/naturalgas/whatever-your-hydrogen-source in order to create the hydrogen molecules.

That means the energy to convert your hydrogen source (hemp) into hydrogen fuel needs to come from a powerplant that is nuclear, solar, wind, coal, whatever.

Hydrogen fuel is NOT an energy source. It's an energy storage mechanism. But I think it's a step forward, because it decouples the energy consumption end from the energy production end. This makes pollution easier to control and regulate, but does not eliminate it. People misunderstand how hydrogen fuel works. But I think it's a step forward, and one we need to take to modernize energy delivery. As for how much it will reduce pollution, that remains to be seen. It will reduce it somewhat, but probably not as much as people think. But hey, I'll take any degree of reduction I can.

[wuushew]

22. Of course you will still need energy to manufacture hydrogen

I am just saying the alcohol yield for hemp is several times better than that of corn. Ethanol can be used as the ideal feedstock depending on what type of biomass is available.

Plus look at all the positive benefits....Amerika gets the fuck out of the Middle East making us safer and less a global rapist, farmers can be paid subsidees for growing an actual benefitial crop unlike subsidees for sugar, rice, peanuts, tobacco etc(which can and should be imported from elsewhere).

Air quality will improve and spur the development of cleaner coal technologies and better cheaper next generation nuclear reactors.

[RandomUser]

25. Good Point

And this is the main advantage of a hydrogen economy. The decoupled energy production and energy consumption ends can be modified independent of each other. So you can upgrade the powerplant instead of upgrading millions of cars to add pollution control. I'm still not sure how much the net pollution will be reduced by yet. A previous poster mentioned the modeled process to be a net increase in pollution...do you know if anyone has modeled the hemp scenario to see if it results in significant cuts in pollution?

[bigtree]

49. "next generation nuclear reactors"

Are to be dual-use facilities for the production of the next generation of nuclear weaponry.

That is this administration's ultimate goal. That's why they included all of the tangential goodies in their energy proposal.
http://energy.senate.gov/legislation/energybill2003/nuclear_matters.pdf

You don't actually believe that they want to replace fossil fuels? Bush?

[im4edwards]

42. not Detroit totally stopping this

the oil companies that own the means of distribution of gas and don't want to have to figure out how to become the means to distribute hydrogen cels (because it isn't necessarily them who will become the ones to do this). Its easy enough for them to hook up with Detroit for some help in this area.

Its possible to make small, inexpensive modifications to the standard internal combustion engine to burn hydrogen. They proved that in the 80's.

[Maple]

8. Here's a hint

invest in hydrogen.

And stop believing hokum put out by the oil industry.

[Tims]

11. Fuel Cell Info

As an electrical engineer I subscribe to several professional publications. The general feeling in the engineering community is that, barring several major breakthroughs, effective fuel cells are no where near becoming an effective replacement for conventional engines in the forseeable future. Though the technology to bring fuel cells to some kind of commercial use is likely to occur on a small scale such as replacing batteries in laptop computers and other power intensive battery powered devices, being able to deliver fuel cells economically enough and reliably enough to power automobiles will be a much bigger challenge than the media and politicians are telling us. I posted some links to some articles on these issues some time ago and will look them up again.

The other thing few people are mentioning is that the fuel cells currently being considered and developed will NOT be using pure hydrogen. As much as some people may call them "myths", the manufacture, handling and storage of hydrogen are major problems, not just technically, but also logistically. It will be a very hard sell to convince fuel distributors and retailers to make the major investment in expensive and technologically complex equipment, especially since the market, even under the best of conditions, will take many years to grow sufficiently to get a return on this investment. Also a ruptured cyrogenic high pressure tank of hydrogen is indeed far more dangerous than a gasoline tank. They can be made safe, but they will be heavy, large and expensive.

Most fuel cell research directed to consumer applications, including automotive, are planning on using ethanol or gasoline as the source of hydrogen in the cells themselves. The advantages here are all practical and economic ones. The delivery system already exists, the fuel is inexpensive, there are no storage and transport issues and the cells themselves are somewhat simpler to make and maintain. This is why you don't hear the uproar against fuel cells coming from the oil industry and their lackeys in Washington, they will still be supplying the fuel.

A fuel cell using these hydrocarbon sources will not be as clean as one which use pure hydrogen because they will produce carbon dioxide along with water as a by-product of the reaction. They will still be cleaner than internal combustion engines and ultimately more effecient.

Fuel cells will not solve our energy or air pollution problems. Only better public transportation, city planning limiting sprawl and a change in public attitude toward owning bigger and more powerful SUVs as status symbols, will we succeed. Fuel cells are no magic bullet.

[papau]

13. Well said - I agree - it appears to be an oil backed joke to stop

the Clinton/Gore push (and now Union of Concerned Scientists sucessfull design) of an off the shelf car with better miliage (50/mph full sized SUV's). A 2050 start date on the hydrogen economy seems reasonable.

[Waistdeep]

17. It's not black and white

Just because the oil companies or the bushies are for something doesn't mean that everything about it is bad. Kneejerk analysis concerning energy policy will be very counterproductive over the next few years.

Amory Lovins, in his Twenty Hydrogen Myths (pdf file) says it better than I can:

"Most environmentalists — perhaps resentful that President Bush has stolen some of their thunder — think FreedomCAR and the Hydrogen Fuel Initiative are a stall, not a leapfrog, and consider the President’s hydrogen announcement mere greenwash for stealthy, rhetorically attractive, but generally anti-environmental substantive policies. (Conversely, The Wall Street Journal’s editorial board — apparently as unwilling to credit any idea environmentalists agree with as environmentalists are to credit any idea the President agrees with — attacks the President’s “reasons for funding hydrogen cars neither smart nor honest.” The White House’s opposition to significant near-term gains in car efficiency unfortunately foments the doubtless unworthy suspicion that hydrogen is being wielded as a political weapon of mass distraction. That lingering odor would best be dispelled by developing and deploying hydrogen to displace most or all petroleum motor fuel in the long run while also saving a lot of oil in the short run by aggressively encouraging hybrid-electric powertrains and other straightforward, available technological improvements that cost less than today’s gasoline. Policy and credibility would also be improved by adding hydrogen dollars to the energy R&D budget rather than appearing to take them out of efficiency
and renewables accounts."

"Both the long-term hydrogen goals and the short-term car-efficiency goals are worthy, in sequence and in coordination; they also support each other, so there’s no reason not to do both. Let the short-term measures support the long- term ones (e.g., by making cars more efficient and electric traction cheaper), and let them both compete fairly. If we don’t, the losers will be Detroit (as foreign competitors take more market share), the Earth, American customers and taxpayers, and their economy, public health, and global security. But if we do, then hydrogen advocates’ utopian visions of a cleaner, safer, and more prosperous world may be right on the money."

[Waistdeep]

16. Woah --- wait a minute

"..a ruptured cyrogenic (sic) high pressure tank of hydrogen is indeed far more dangerous than a gasoline tank.."

Nobody is seriously talking about cooled, liquid hydrogen tanks in hydrogen powered vehicles. The problem is in producing compressed hydrogen (uncooled) tanks which can contain enough hydrogen in a volume close to current gasoline tank volumes to make greater than 300 mile cruising ranges possible. I can try to find the reference, but I know there are feasible tanks, made of carbon fiber composites which can hold compressed hydrogen at 700 bar ( approx 10,000 psi!) in safety. I believe that 350 bar is the current standard for hydrogen vehicles.

[Tims]

43. 10000 PSI

Anything at 10000 psi is dangerous. Think about it. People are killed on a regular basis over inflating tires at orders of magnitude lower pressures. Cryogenic (got it right this time) storage is the only way to keep the pressure reasonable. These can bleed off hydrogen safely if the pressure builds.

My point is that the people actually working on this do not see using pure hydrogen as a practical means of building commercially viable fuel cells.

[Waistdeep]

46. Believe it or not, 10000 psi works!

You said: "Anything at 10000 psi is dangerous. Think about it"

700 bar (10000 psi) tanks have already been approved in Germany for compressed hydrogen storage in automobiles. They have been tested above 1656 bar. The US has approved 345 bar tanks and are expected to approve 700 bar tanks shortly. They are filament-wound carbon-fiber tanks lined with an aluminized polyester bladder and are unscathed in crashes that flatten conventional autos.

The pressure is stepped down before leaving the tank so there are no high pressure hydrogen lines.

A 700 bar tank is about 5 times the volume of a gasoline tank holding the same energy. But a fuel cell/electric motor is about 2-3 times more efficient than an internal combustion engine, so the tank need be only about twice as large as a conventional gas tank for the same range.

[stevedeshazer]

21. *ding*

Great post, you said it better than I was about to (until I read yours.)

http://images.google.com/images?q=tbn:uEcTb09fVLcC:

[mistertrickster]

23. I basically agree with your analysis of fuel cells, but I live in the

"natural gas" belt (Kansas, Oklahoma), and I don't see why H would be any more dangerous or hard to use than natural gas. It is 1/3 as dense which means that it would leak three times faster, but other than that, I don't see how it's that much different than natural gas.

[Tims]

44. Higher Boiling Point

Natural gas has a much higher boiling point and will liquefy at room temperature under reasonable pressures. Hydrogen, on the other hand, will only liquefy at extremely low temperatures and under high pressure.

You bring up an important point about leaks. Because of the small molecular size of hydrogen, it is indeed very difficult to prevent leaks. Only Helium is worse. Molecular hydrogen easily diffuses through many materials commonly used as seals and will find escape routes through the most microscopic of cracks or irregularities.

[JohnyCanuck]

24. The problem with Hydrogen

While this article Why Hydrogen is No Solution might be possibly too pessimistic in it's outlook re. the viability of a hydrogen economy, it's probably a good summmary of what the problems are that we will need to overcome and work around if hydrogen is to play a meaningful role in the economy.
From Why Hydrogen is No Solution:
The basic problem of hydrogen fuel cells is that the second law of thermodynamics dictates that we will always have to expend more energy deriving the hydrogen than we will receive from the usage of that hydrogen. The common misconception is that hydrogen fuel cells are an alternative energy source when they are not.

In reality, hydrogen fuel cells are a storage battery for energy derived from other sources. In a fuel cell, hydrogen and oxygen are fed to the anode and cathode, respectively, of each cell. Electrons stripped from the hydrogen produce direct current electricity which can be used in a DC electric motor or converted to alternating current.41

Because of the second law of thermodynamics, hydrogen fuel cells will always have a bad EROEI. If fossil fuels are used to generate the hydrogen, either through the Methane-Steam method or through Electrolysis of Water, there will be no advantage over using the fossil fuels directly. The use of hydrogen as an intermediate form of energy storage is justified only when there is some reason for not using the primary source directly.42 For this reason, a hydrogen-based economy must depend on large-scale development of nuclear power or solar electricity.




Here's how I see the picture. With gasoline we have a highly energy dense fuel that contains lots of energy per unit of gasoline. This is a fuel thatf for now is still relatively easy to obtain by basically pumping it out of the ground and that has been manufactured for us over millions of years by mother nature (true it does take some energy to produce gasoline in the refining process from crude oil).

Since gasoline is such a very concentrated and powerful sources of energy, I'd imagine that at the end of the day the energy stored in a gallon of gasoline is more than the energy expended in pumping it out of the ground and refining it out of crude oil. The problem we'll be facing after world oil production peaks in the not too distant future, is that the energy used to obtain each new gallon of gasoline will continue to increase as we will have to expend greater and greater amounts of energy to get the remaining crude oil out of the ground or to refine gasoline out of less and less desirable grades of crude oil. At some point we would reach a saw off point where we will expend more energy in recovering a gallon of gasoline than the energy provided by that same gallon of gasoline.

With hydrogen we've got to manufacture the product from scratch by using energy from other sources such as burning fossil fuels or using electricity generated by windmills, nuclear power etc. Every time you expend or use energy the laws of thermodynamics kick in and some of the source energy becomes lost and unrecoverable. From what I can see so far, the hydrogen detractors are saying at the end of the hydrogen creation process we'll have less energy (in the hydrogen) than the energy expended to create that hydrogen in the first place, giving a net loss in energy. It would be more efficient to use that input energy directly rather than converting it into Hydrogen for storage.

[Waistdeep]

27. Of course

But, just because some energy is lost in translation in one stage of conversion doesn't mean that whole system is more inefficient. You have to look at ALL the energy losses. Suppose for argument that we are comparing the efficiency of a gasoline powered automobile with a hydrogen-fuel cell vehicle. Let's further assume that the hydrogen is indirectly produced from fossil fuels, either by electrolysis via electricity from a fossil fuel power plant, or the more common reforming of natural gas. Sure, there is some energy loss. But what about the conversion of gasoline to mechanical energy in the internal combustion engine? There are HUGE losses there. A fuel cell + electric motor is far more efficient at converting stored energy (hydrogen) to mechanical energy than an internal combustion engine is in converting gasoline to mechanical energy. You have to look at the whole system from the initial energy source to final output to talk about efficiency. There is a strong case to be made that, even with the energy costs of manufacturing hydrogen from fossil fuels, that hydrogen cars could be made with greater efficiencies than corresponding fossil fuel powered internal combustion cars.

And when you have electricity that is produced from a renewable source, such as solar, hydroelectric, or windpower what is the alternative to conversion to hydrogen? A long extension cord?

[JohnyCanuck]

30. Good point

what about the conversion of gasoline to mechanical energy in the internal combustion engine? There are HUGE losses there. A fuel cell + electric motor is far more efficient at converting stored energy (hydrogen) to mechanical energy than an internal combustion engine is in converting gasoline to mechanical energy. You have to look at the whole system from the initial energy source to final output to talk about efficiency

[bigtree]

31. This is the main problem

"nuclear power etc."

[wuushew]

32. bigtree not all nuclear power is evil...

please do not judge western saftey records with those under the former Soviet Union. Nuclear power can and does work in places like France where it supplies 70% of the electricity. The plain fact is that nuclear power is no where near cost competitive with coal or oil in this country which is a shame since coal in particular adds uncounted tons of sulfur, mercury and radioactive debris to air every year. I did appreciate your post on nuclear space exploration, however if things were like they were today in the 1970's Pioneer or Voyager would have never been launched.

[bigtree]

36. more nuclear energy means more radioactive fuel

Where do we put it when it is spent? Renewable fuels are a slippery slope into the new generation of nuclear weapons and nuclear plants. What communities will have to bear the existence of the new plants?

What application is worth the risk of the further exploitation, misuse, and mishaps that are the inevitable consequences of this unnecessary industry? Nuclear energy accounts for only 20% of the electrical power supply in the US. The remaining bulk is used to preserve an anacronistic weapons program which further endangers this and future generations, unnecessarily.

What do we sacrifice by refusing to expand the hydrogen program into nuclear production?

What do we gain? Safe, renewable alternatives perhaps? A safer world?

Hydrogen has its own disposal problems, especially if you generate it from nuclear materials. Why don't these geniuses stop playing with this stuff? I'm sick of the promises of safety. It's not an intellectual matter. This new push to revive the nuclear industry in America will bring new 'usable" nukes and more sadness for our planet. I wish you could understand that this industry won't stop until they exploit the people and the land, to our detriment. This is the history of this industry in the US. We are still cleaning up the waste from 1956 at the Idaho nuclear lab and this is to be the lead research facility for the new generation of nukes and nuke plants!

And then where will we go when the water and the air is irrepairably polluted? France?

"The old man told him: Soon the water will not be safe. It will look like water but you will not be able to drink it"

[RandomUser]

51. Not necessarily

Newer generations of nuclear reactors with new technology can produce less radioactive waste. We need to spend more money on researching nuclear energy technologies.

Currently, nuclear reactors work using nuclear fission, thus generating nuclear waste. If we pump more money into nuclear technology and devise nuclear fusion reactors instead of nuclear fission, we'll be much better off both in terms of reducing nuclear waste and in terms of energy returns. We're getting close with soda-can implosion and magnetic bottle prototypes. Call me idealistic, but cold fusion would really solve all our energy problems.

[Bread and Circus]

35. Sounds like you know your stuff....

but they have buses running in Chicago
on hydrogen fuel cells. They seem pretty big.
A lot bigger than a lap top. Have you heard of
that. From what I have read, H2 fuel cells are really
promising.

[Tims]

45. Busses aren't cars

A big bulky fuel cell and storage system and a vehicle with a price tag already over $100,000 make use of current technology feasible with busses. Turning this technology into something that the public can afford and want to buy is another issue entirely. Cities can also provide their own fuel delivery systems for their fleets, something the consumer cannot do.

[Bread and Circus]

53. You are making very good points...

I don't disagree. I have read some stuff that is
not consistent with all you say but I am not an
engineer. Thanks for your insight.

[RandomUser]

15. Hydrogen "fuel"

is good, but not a panacrea. Don't think of hydrogen as an energy source like gasoline or natural gas or even solar cells. Think of it as a fuel storage mechanism. This is a common mistake made about hydrogen fuel cells.

Unlike gasoline, which you can pump out of the ground, or solar cells or wind mills, hydrogen has to be manufactured. It's made by stripping the hydrogen atoms from hydrocarbons like natural gas. An energy source is needed for that. Hydrogen fuel cells are more like rechargeable batteries, it stores the energy, but the energy needs to be generated first by another mechanism.

So you might use something like a coal-fired powerplant, or a windmill powered power plant, or a solar powered power plant (you get the idea), to process hydrocarbon(natural gas) by stripping the hydrogens off those molecules. The energy from the coal/solar/wind/nuclear process goes into the hydrogen fuel, which releases the energy when it's combusted with oxygen to create water.

So you see, hydrogen fuel cells will still produce pollution on the production end during the power plant phase, but it won't create pollution in the consumption end when you combuste it with oxygen to make water. The pollution is basically being shifted from your car's tailpipe to the power plant's smokestack.

That being said, hydrogen fuel is a good thing, because regulating the pollution controls of a few smokestacks is easier than regulating the tailpipes of millions of cars bleching into our streets. But make no mistake, hydrogen is not really an energy source, it's just a more environmentally friendly energy storage mechanism...kind of like a better rechargeable battery. The energy to charge the battery still has to come from somewhere.

[Terwilliger]

18. water vapour

just kinda hard to put into practical practice right now

[WaterDog]

34. The problem is

when the hydrogen escapes into the atmosphere before being combusted. I read it in the newspaper a few weeks ago. I guy did a study regarding the escaped fuel. If about the same amount of hydrogen escaped into the atmosphere as current fossil fuels do, the ozone layer is in deep s**t. The retort to the argument was that hydrogen is too valuable a fuel to let it escape. But how can anyone guarantee that a significant amount won't escape when it's being used on such a mass scale every day all over the country and world?

[Waistdeep]

37. This has been debunked

edited for format:

I'm not really a Rocky Mountain Institute flack, but, once again from Twenty Hydrogen Myths:
(by the way, I first came across Amory Lovins as a graduate student in Physics at Berkeley in the late 1970s and was blown away by his combination of scientific competence and vision. Trust me, he knows what he is talking about)


"A final climate-atmospheric-science myth was instantly created and intensively publicized worldwide after the respected journal Science embarrassingly published in June 2003 a paper that should not have passed peer review. CNN Headline News, for example, aired half-hourly reports of the “dark cloud” of environmental risk just discovered to be hanging over those supposedly clean hydrogen fuel-cell cars. The Science paper projected that molecular hydrogen releases into the atmosphere could be ~4–8-fold higher in a hydrogen economy than in today’s fossil-fuel economy, and that this could cause a variety of problems with climatic stability and the protective ozone layer in the stratosphere, ranging from hydroxyl-radical chemistry to stratospheric cloud formation and disturbance of high-altitude photochemistry. Assuming that theCalTech authors’ climate science and treatment of the fate of released hydrogen are correct (both are in some dispute), their whole argument is nonetheless invalid because they assume a 10–20% hydrogen leakage rate, which is about 10–400 times too high. If the leakage rate were in fact 10–20% from today’s 50 MT/y hydrogen production, then the total hydrogen releases caused by human activity, which the authors say are 15±10 MT/y — all previously believed to come from incomplete combustion and methane emissions of fossil fuels and biomass — would instead be roughly one-third to two-thirds due to leaks of industrial hydrogen. No such source term has been observed, and any hydrogen industry that leaked so badly would have serious problems of both safety and profitability."

"How did the CalTech authors arrive at their assumption of 10–20% hydrogen leakage? They simply misread both of their references. The first, which clearly stated that the German hydrogen system loses 0.1% of its throughput, also offered as an example that a completely hydrogen based global economy leaking 2–3% (and using no direct renewable energy) would emit about as much hydrogen as the fossil-fuel system emits now. A worst-case example was also presented that assumed 10% leakage for the sake of argument, although though it stated that 2–3% was more reasonable. The CalTech authors read all this to mean that the paper had “reasonably projected” a 10% leakage rate. They then claimed that “Losses during current commercial transport of H2 are substantially greater than this, suggesting to us that a range of 10 to 20% should be expected.” Where did they get the idea that “current commercial H2 transport” losses exceed 10%? remarkably, from a paper that said nothing whatever about such losses. Its only quantitative estimates were for the daily boiloff rates of liquid hydrogen in small shipping containers (cryogenic truck and rail tankers). In fact, liquid hydrogen is only 10–3 of the world hydrogen market, boiloff is usually burned or otherwise reused rather than released, and any serious volumes of liquid hydrogen would be delivered via pipelines or large marine vessels150 rather than small trucks; but apparently the CalTech authors overlooked all that. Due to the high cost of making and delivering liquid hydrogen, now used largely for space rockets, it will probably never compete economically in significant markets except aircraft, where hydrogen losses would be very low and hydrogen usage would be less than a tenth of the total market. Prior technology assessment is useful, indeed essential; this is simply not a good example of it. The CalTech authors concluded that, whatever its potential climate advantages from reduced CO2 and other emissions, hydrogen leakage from a global hydrogen economy could considerably increase the risk to stratospheric dryness and photochemistry. This is incorrect because:

• They grossly overstated the hydrogen leak rates: instead of their assumed 10–20%, a more plausible estimate is at worst 1–2 percent, more likely a few tenths of a percent or less.152 The authors do agree that hydrogen “emissions could be limited or made negligible, though at some cost,” and no doubt the furore over their paper will help to focus attention on this issue, but they seem unaware that the hydrogen industry already achieves extremely low leakage as part of its normal operating practice and at modest cost, simply as a prudent strategy for public and asset protection.
  
• They didn’t credit hydrogen for its greater end-use efficiency, enabling less hydrogen to deliver more service than can the fossil fuels it displaces.
  
• They didn’t credit a hydrogen economy for reducing or eliminating most of the present causes of hydrogen emissions, which originate in fossil fuel and biomass usage. (Direct use of renewable energy without going through hydrogen would of course displace fossil fuels without any hydrogen leaks.) Altogether, these factors would make a soundly designed hydrogen economy reduce current releases of hydrogen by one or perhaps two orders of magnitude, to a level well below natural hydrogen releases. Thanks to the authors’ and journal’s carelessness, much research will now be done to ensure this outcome, which was highly likely anyhow, and many hydrogen advocates will spend as much time debunking this new myth as they already spend rebutting older ones like the Hindenburg (Myth #2)."
  

[George_Bonanza]

38. WaistDeep is right

I hope nobody is against H-power simply because Bush isn't head over heels against it. That's just childish.

Is there a "perfect fuel"? Maybe. I don't know. Hydrogen isn't it. But with the carbon monoxide pollution eliminated, and fuel efficiency improved, which means each fuel cell will last longer than a tank of gas, it will at least greatly slow down the destruction of the environment. We should pursue this path because obviously it's better than fossil fuels. Just because it doesn't actually plant trees and accelerate their growth doesn't make it bad.

[Adjoran]

39. Several points

In addition to the explanation above, which is quite accurate, hydrogen would not just be a "wash" in energy or pollution if it is produced using fossil-fuel-fired plants because of the economy of scale in production. It is cleaner and more efficient to use energy from a few production facilities than from 100 million internal combustion engines.

Gasoline, as has been pointed out, is actually a very efficient energy source. The problems come from the need for internal combustion, which is very inefficient in wasting that energy, and producing toxic by-products.

Hydrogen is no panacea, of course. But even if its use eventually cut our use of fossil fuels by 30%, that would be a great economic and environmental benefit.

The advantages of hydrogen are two: it is efficient, and abundant in nature. Its volatility brings most of the technical problems. Most of industrial progress is achieved by simply solving technical problems.

Fuel cells are one possible means to solve some of the technical difficulties, but they are not the only ones.

[Mairead]

41. I didn't see anyone in the thread mention that the only easy source of

H is water. But water is already an endangered resource. So it seems to me that we already have a serious conflict. No?

[htuttle]

47. Actually, water is an expensive source of hydrogen

...energy-speaking. It takes a large portion of the energy you get out of the hydrogen to separate the water.

The 'easiest' way to get hydrogen, in as far as how much energy you put into it to get the hydrogen, is to crack it out of petroleum products.

And that's how I've heard they've been planning on generating it, not via water separation.

[Tims]

50. It's not an easy source

The amount of energy necessary to separate hydrogen from oxygen in water is the same as the energy released when hydrogen and oxygen combine, and this is only the theoretical limits. In reality much more energy would be required generating hydrogen from water than would be produced by the fuel cells. This does not say that this is a bad thing. As others have mentioned, it is a fairly efficient means of storing energy produced in conventional power stations.

Economically, using a hydrocarbon fuel directly in a fuel cell or producing molecular hydrogen from these hydrocarbon sources will always be cheaper. Hydrogen is much more loosely bound in hydrocarbons than in water, and therefore less energy is necessary to extract it. Even if petroleum prices skyrocket, it will still be cheaper to extract hydrogen from alcohol produced from grains, than to produce it directly from water. The fact that fuel cell can run on alcohol without first turning it into molecular hydrogen means that from an economic standpoint, this will probably be the way fuel cells will be implemented.

[RandomUser]

52. Hydrogen source is not the same as Energy source

Hydrogen can be gotten from many sources, such as hydrocarbons(natural gas), hemp/ethanol, biodeisel, even water. That's not the issue. The issue is getting the energy to create hydrogen from those sources. You need a traditional power plant (coal-fired, nuclear, solar, wind, whatever) to conver the water/naturalgas/hemp/whatever into hydrogen. Once again, Hydrogen is NOT an energy source, but an energy storage mechanism.