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Boeing to Develop a Fuel Cell Powered Airplane

gilgsn writes: "From Yahoo News: Boeing is working with a light airplane manufacturer in Spain on a fuel cell powered plane. The efficiency of electric motors, with their reliability, acceleration, lack of vibrations and noise has a lot to offer to general aviation. The project aims at exploring environmentally friendly modes of propulsion. I can easily imagine a hybrid aircraft using fuel cell technology for take-off and altitude gain, coupled with solar cells to sustain flight. I hope a kitplane manufacturer in the United States will read this. I can't wait to fly a fuel cell powered ultralight!" CD: The question is can a fuel cell deliver enough energy for a flight long enough to be practical.

205 comments

  1. solar power by spiny · · Score: 0, Offtopic

    >The question is can a fuel cell deliver enough energy for a flight long enough to be practical.

    well, the solar power car race shows that, cars at least, are able to harvest enough power on the move to make them practical (if expensive) so who knows...

    though i'd be more reasured if a plane i was in had some sort of conventional power backup in case it got cloudy ....

    --

    Fry: heh, Yakov Smirnoff said it
    Leela: No he didn't.
    1. Re:solar power by Drakin · · Score: 1

      Fuel Cell

      say it with me "Fuel Cell"

      Not solar powered. Chemicals reacting.

    2. Re:solar power by Anonymous Coward · · Score: 0

      Given the weight of solar cells and their limited power output, it might be practical to sustain flight using solar cells but only if the airplane rolled along the ground, much like a solar powered racing car -- they could call it the "landplane".

    3. Re:solar power by spiny · · Score: 0

      sorry, i missed that, could you repeat it ?

      --

      Fry: heh, Yakov Smirnoff said it
      Leela: No he didn't.
    4. Re:solar power by nosferatu1001 · · Score: 1

      Yes, hydrogen and oxygen. So you electrolyse the resulting water and you get...hydrogen and oxygen again, ready to be stored back in the fuel cell.

      you see?

      now whether it is practical or not is another thing....

    5. Re:solar power by nusuth · · Score: 1

      I don't see why solar power crept into this discussion but if you want to check how much power a solar panel can deliver, you really don't have to look at car races and those stuff. Just check the number, how much solar heat/unit area reaches higher protions of the earth, how much wing area can a passanger plane possibly have, how much of light on these wings can be actually converted to electricity and how much electric energy does a passanger plane require? You'll see more than two orders of magnitude difference. Solar power is not practical for self powered vehicles operating on earth, and no breakthru will change it. Thermodynamics puts an upper limit on conversion effciency, the sun-earth system puts an upper limit to amount of sunlight incidence you can expect; you can't change these with advanced technology. You can sure design a solar powered plane (and someone actually did) but it would have hard time keeping itself flying in the middle of a summer day, without 100s of passangers and their luggage. Most people seem to think that if you use solar energy to charge batteries, or break water, then use that for powering something, it is a solar powered thing. It is not, just like my computer is not a hydroelectric powered computer. So I don't deny the possibility that solar power may be utilized in some way, don't get me wrong.

      --

      Gentlemen, you can't fight in here, this is the War Room!

  2. Risks involved by metlin · · Score: 3, Informative


    He recently witnessed a demonstration of a hydrogen-fueled automotive fuel cell that was so environmentally friendly its only byproduct was water safe enough to drink.


    So they are talking about a H-O fuel cell. Agreed, but what about the risks of explosion? Seriously, I'd done some fuel cell research a couple of years back and one of the biggest problems the people doing it faced was regulating the flow of hydrogen & oxygen. More often than not, the flow would go awry. Ofcourse I'm not talking about small scale ones, I'm talking of large ones, developed for seeing how well fuel cells could be used in industrial areas. I'm sure these would be the kind of ones which would be used in such things as planes, too.

    And given something like a plane, we cannot afford to have such uncertainities and risks.

    1. Re:Risks involved by itarget · · Score: 1

      And oil-based fuels are harmless?

      --

      "Where shall the word be found, where will the word resound? Not here, there is not enough silence." -T.S. Eliot
    2. Re:Risks involved by DarenN · · Score: 1

      Ford are roadtesting fuel-cell cars at the moment.
      The Focus version looks pretty snazzy :)

      Well the point of this is that if a large scale manufacturer like ford feels that it is safe enought to drive the roads, then I can't see why it could not be made viable for planes.

      --
      Rational thought is the only true freedom
    3. Re:Risks involved by Billly+Gates · · Score: 3, Insightful
      "Agreed, but what about the risks of explosion?"


      Jet fuel can explode too. A 767 jet carries 200,000 gallons of jet fuel. Enough to fill a very large swimming pool. That can blow a plane apart no problem. I was just 3 blocks from the world trade center when the planes hit and believe me I say that during the explosion, the sound was so loud that it could be heard as far as 20 miles away and the fireball was over 30 stories high and blew over the top of the towers. I talked to people as far as staten island which is about 15 miles away and they heard it. Even if the sound was from the high acceleration of the aircraft hiting the building and not the fuel exploding, the size of the fireball itself showed how much power an exploding tank can do. Either way, if an oil filled tank or a fuel cell explodes the passengers are dead.

    4. Re:Risks involved by Gordonjcp · · Score: 4, Interesting

      Well, one (imperial) gallon - 4.5 litres - of petrol, in vapour form, has roughly the explosive power of 1kg of dynamite. So, consider the explosive power of the average fully-fueled car. My Citroen XM has a 17-gallon (roughly 80l) fuel tank. Big boom.

      The explosion risk is actually slightly higher for unleaded petrol (technically they're all unleaded in the UK now, but in this case I mean 95RON lead-free) than for 98RON Lead-free Four Star. This is because instead of nice, safe, but *slightly* poisonous Tetraethyl Lead, lead-free uses Benzine, which is much more volatile, extremely poisonous and highly carcinogenic.

      Diesel fuel doesn't really explode well at all. Jet fuel (basically very clean paraffin, like heating oil) is somewhere in between.

    5. Re:Risks involved by rcw-home · · Score: 2
      Well, one (imperial) gallon - 4.5 litres - of petrol, in vapour form, has roughly the explosive power of 1kg of dynamite.

      Actually, gasoline has an energy density ten times that of dynamite. Your gallon of gas fumes (almost 3kg) is closer to 30kg of dynamite.

      And yes, it's a very big boom.

    6. Re:Risks involved by Gordonjcp · · Score: 2

      I stand corrected! Now I don't want to drive home :-)

    7. Re:Risks involved by x0 · · Score: 4, Informative

      Actually, the 767-400ER carries just a bit less than 24,000 gallons. http://www.boeing.com/commercial/767-400ER/product .html

      --
      In the immortal words of Socrates, who said; 'I drank what?'
    8. Re:Risks involved by ruudn · · Score: 1

      A Boeing 767 has a maximum fuel capacity of about 24000 US gallons. See
      Boeing Product Information for more information.

    9. Re:Risks involved by Anonymous Coward · · Score: 0

      I think he meant 200,000 pounds of fuel. Pilots of large aircraft track fuel in pounds not gallons. 24,000 gallons is about 192,000 pounds of fuel.

    10. Re:Risks involved by Anonymous Coward · · Score: 0

      > And given something like a plane, we cannot
      > afford to have such uncertainities and risks.

      Worked for Apollo 11:

      http://www.nasm.edu/galleries/attm/a11.jo.fc.2.h tm l

    11. Re:Risks involved by muleboy · · Score: 1
      Seriously, I'd done some fuel cell research a couple of years back and one of the biggest problems the people doing it faced was regulating the flow of hydrogen & oxygen.

      I have also worked on fuel cell research, and I agree that this is the biggest problem. The storage tanks for hydrogen are pretty safe at this point, although if they do rupture for some reason, it's bad news. The big problem is that it is hard to keep the oxygen and hydrogen separated with 100% certainty, 100% of the time. Small fires in large fuel cells were common, at least in the research setting. It's not really a problem for research work, and it usually just destroys the cell where it happens without causing a large fire, but you can't have it happening in a plane.

    12. Re:Risks involved by mr100percent · · Score: 1

      There aren't 200+ people in a space capsule, not to mention the relatively higher risk of the thing crashing into a large urban neighaborhood.

  3. Fuel Cell Tech by brainboyz · · Score: 2

    This stuff seems to be coming along faster and faster these days. Heck, I wouldn't be surprised if in the next 3-5 years they have small fuel cell generators for backup power in homes (I know it requires a converter, but who knows?). But I'd rather have one of these in my electric cars rather than 12 or so huge car batteries, and having it last twice as long is a good bonus!

    One more way to reduce pollution in urban areas.

    1. Re:Fuel Cell Tech by ErikZ · · Score: 1

      GE is currently testing home fuel cell power generators. I have no idea how much longer they want to collect data though.

      http://www.gepower.com/dhtml/distributed_power/e n_ us/microgen/faqs.jsp/

      --
      Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
  4. great...more dependence on weather by htmlboy · · Score: 2

    resgarding to the idea of a plane that takes off using fuel cells and sustains flight with solar power (valid given the relative immaturity of fuel cells and their small power capabilities for something like a cross-country flight), it doesn't seem like something that'd find commecial success. with more restrictions on what you can bring on the plane with you these days, planes that need to fly through at least patches of direct sunlight are just going to annoy their passengers. there are enough reasons to for flights to be late now*. why introduce another one?

    *my favorite was when i was flying on a smaller outfit, and our plane couldn't get into the terminal and unload because the union workers were on their mandatory breaks and when they got back serviced the big airlines (which arrived after us).

    1. Re:great...more dependence on weather by nosferatu1001 · · Score: 1

      Direct sunlight? Fly above the average cloud height!

    2. Re:great...more dependence on weather by conway · · Score: 1

      Well, I don't agree about the weather -- most commercial aircraft fly above cloud level.
      The problem of course is night flying!
      You'd effectively be restricting flights to daytime only. (And this would be a big problem for long flights -- there'd be only a tiny flight start window to get sunlight during the whole flight.)

    3. Re:great...more dependence on weather by Anonymous Coward · · Score: 0

      If you flew from East to West (only) you'd be in good shape...

  5. Which Fuel? by squaretorus · · Score: 5, Interesting

    With Fuel Cells you boil down to a trade off between the efficiency and cost of the fuel.

    Plain old hydrocarbons are cheapish, easy to handle, and not overly dangerous in a 'leak' situation.
    But they require hyper advanced self cleaning fuel cells that wear out quickly.

    Pure methanol is expensive (purification always costs), easy to handle, and not overly dangerous in a leak situation.
    It works in cheaper, more reliable, longer lasting and lighter fuel cells.

    Hydrogen is expensive, difficult to handle, and pretty damn dangerous stuff in ANY situation.
    It works best with fuel cells, pretty much optimal.

    A fuel cell that can handle ANY carbon rich material, and takes O2 from the atmosphere would be the holy grail. You could use argicultural by products to produce methonal, dig up oil, LPG, any burnable liquid essentially.

    A rethink on the air network strategy to produce lighter, smaller, more efficient aircraft which possibly fly a bit slower and take shorter 'hops' would bring Fuel Cell flight closer.
    This would be a worthwhile trade off for a more environmentally sound and sustainable flight infrastructure.

    Boeing and Airbus both seem committed to increasing the size of aircraft overall. Maybe its time for a serious rethink?

    1. Re:Which Fuel? by redcliffe · · Score: 2, Informative

      The good thing about hydrogen/oxygen is that it is easily rechargeable. You can hook it up in a closed loop, with the fuel cell taking 2H2 and O2, and converting it to 2 H2O. You can then take the resultant water to a storage tank, then during charging electrolsys splits the water back into Hydrogen and Oxygen. I'm not sure of any other fuel cell system that can do this.

      David

    2. Re:Which Fuel? by JimPooley · · Score: 1, Flamebait

      So you want to finish the job of destroying global tourism that scaredy-cat yanks are already starting, eh?
      Personally I'd rather we made bigger concordes!

      --

      "Information wants to be paid"
    3. Re:Which Fuel? by tbo · · Score: 3, Insightful

      A rethink on the air network strategy to produce lighter, smaller, more efficient aircraft which possibly fly a bit slower and take shorter 'hops' would bring Fuel Cell flight closer.
      This would be a worthwhile trade off for a more environmentally sound and sustainable flight infrastructure.


      Even more environmentally friendly would be if everyone just walked. I got news for you--transportation technology is based on getting people where they want to go fast and cheap. Many small planes on short flights means a lot more overhead, and a hell of a lot more fuel spent taking off and landing (the most inefficient parts of flight), not to mention longer travel times.

    4. Re:Which Fuel? by FrankBough · · Score: 1

      A rethink on the air network strategy to produce lighter, smaller, more efficient aircraft which possibly fly a bit slower and take shorter 'hops' would bring Fuel Cell flight closer.
      This would be a worthwhile trade off for a more environmentally sound and sustainable flight infrastructure.


      And for better hops, just power it with beer.

    5. Re:Which Fuel? by blane.bramble · · Score: 2, Insightful

      A rethink on the air network strategy to produce lighter, smaller, more efficient aircraft which possibly fly a bit slower and take shorter 'hops' would bring Fuel Cell flight closer.

      That doesn't solve the problem of trans-atlantic flights. Or any long-distance flight (how many people would want to take off and land 8 times to go from the UK to Australia for example?). Also as take-off and landing are the most dangerous parts of air-travel, increasing the frequency of them would make air-travel more dangerous as well.

    6. Re:Which Fuel? by Rogerborg · · Score: 5, Informative
      • Hydrogen is expensive, difficult to handle, and pretty damn dangerous stuff in ANY situation

      What's so dangerous about hydrogen in "ANY" situation? AFAIK, the big danger is leakage during storage, which is harder to detect than a leak of hydrocarbon vapour. A leak in use - in a moving vehicle - isn't significantly more likely than a hydrocarbon leak, nor more dangerous, as you have to be very unlucky to achieve the right fuel/air mixture at the right ignition point for sustained combustion.

      Is this some Hindenburgh knee jerk response? The Hindenburgh was painted in a substance not dissimilar to rocket fuel, and even so, 61 of the 97 people on board survived. That's a pretty good survival rate for an aircraft that exploded on landing.

      References that demonstrate the danger of hydrogen in "ANY" situation would be greatly appreciated.

      --
      If you were blocking sigs, you wouldn't have to read this.
    7. Re:Which Fuel? by znu · · Score: 3, Interesting

      You're ignoring the "where they want to go" part of your own statement. Smaller planes flying to smaller airports will put people closer to their final destinations. Direct flights everywhere will save people the frustration involved in layovers. Less reliance on major hubs will relieve congestion and delays. All things considered, in most cases you'd probably have much shorter total travel times (including time to get to/from airport and to get through the airport onto the plane and into the air), and a major reduction in the sort of circumstances that bring on "air rage".

      --
      This space unintentionally left unblank.
    8. Re:Which Fuel? by squaretorus · · Score: 2

      Many small planes on short flights means a lot more overhead

      WRONG. Long haul flights are no nore efficient overall than regional flights of under 1000 miles which would, probably, be within the range I refered to.

      In the UK it is cheaper to fly the length of the country than to take a coach / train because the overheads of flight are so low. These are normally relatively small aircraft.

    9. Re:Which Fuel? by squaretorus · · Score: 2

      Agreed. This isn't a one shop solution. I walk to the toilet, I cycle to work, I drive to visit my parents, I fly to the Med for a holiday.

      That an environmentally preferable solution is available for short haul should be a good thing. That we have to stick with 747s for long haul may just be a law of physics.

    10. Re:Which Fuel? by AndyMan! · · Score: 1
      A leak in use - in a moving vehicle - isn't significantly more likely than a hydrocarbon leak, nor more dangerous, as you have to be very unlucky to achieve the right fuel/air mixture at the right ignition point for sustained combustion.
      Tell that to the poor shmucks on the last Concorde flight. _Am
    11. Re:Which Fuel? by Lockjaw · · Score: 1

      Hydrogen has an extremely large flammability range. This means that you can have a relatively small amount of H2 mixed with air, or a relatively small amount of air mixed with H2, and the mixture still burns. Relative here means compared with hydrocarbons, particularly alkanes (methane, propane, octane, etc.).

      Another thing is that H2-air detonates much more easily than a typical hydrocarbon-air mixture, meaning your explosion can be much more destructive.

      The only hydrocarbon that competes with hydrogen in these matters is acetylene (C2H2), which is some pretty nasty stuff in its own right (have to store dissolved in acetone, etc.).

    12. Re:Which Fuel? by Lockjaw · · Score: 1

      Consider some of this guy's papers. I don't have a good web-accessible reference (try searching Journal of Propulsion and Power), but there has been some talk of lithium fuel-cells. An interesting thing about them is that the plane would start light and get heavier as it flew further, since the lithium is too expensive and environmentally questionable to just chuck the reacted stuff out the back. The idea does sound a little wacky, but the power density looks to be quite good.

    13. Re:Which Fuel? by jonnythan · · Score: 1

      I make my own acetylene for fun on the weekends.

      Yup, I'm a caver and I use a carbide lamp. Water + calcium carbide = acetylene. The lamp produces acetylene which it shoots out of the tip..light it and you have a nice underground light source.

      My particular lamp was made in 1926.

      I buy large (60 lb)n barrels of carbide for about $100 including shipping and Hazmat fees.

      The lamps are known for having pretty spectacular explosions, and the 'used' carbide gets carried out of the cave in a backpack...I've seen quite a few backpacks spontaneously explode from acetylene buildup..

      Acetylene is definitely fun stuff ;)

    14. Re:Which Fuel? by Anonymous Coward · · Score: 0

      They were very unlucky. Of the millions of flights that have flown succesfully in the last few years, theirs happened to be the one to blow up.

      And then there's the millions of cars that are at the same, if not worse, risk of spontaniously blowing up from fuel tank leaks.

    15. Re:Which Fuel? by Anonymous Coward · · Score: 0

      It's fun for welding torches too. :)

    16. Re:Which Fuel? by Zachary+Kessin · · Score: 2

      Yes but you loose energy everytime you do it. The amount of power you get out of burning the H2 is *LESS* then you need to split the H20 into H2 and 02. So while it is a reversable change it costs energy each time.

      Its the 2nd Law of thermodynamics.

      --
      Erlang Developer and podcaster
    17. Re:Which Fuel? by Zachary+Kessin · · Score: 2

      It is a long way to getting a Fuel Cell Airliner. It sounds like they want it for an APU (to supply power on the ground etc) As it works out a 747 is rather Enviormentally friendly. The 777 more so. Yes they burn a lot of Jet-A but if you take the amount of Fuel per passenger mile or Kilogram mile its probably less than a lot of other forms of transport.

      --
      Erlang Developer and podcaster
    18. Re:Which Fuel? by redcliffe · · Score: 1

      Yeah, but it's gotta be a hell of a lot better than using batteries, or petrol in an ICE engine.

      David

    19. Re:Which Fuel? by squaretorus · · Score: 2

      As it works out a 747 is rather Enviormentally friendly

      I'm sorry, but this is untrue urban legend nonsense that rears its head whenever people think the green movement is trying to take away their right to fly.

      A single transatlantic flight is equivalent to 5 years of the average British commute by car (35 minutes a day in each direction). And that is the 'per person' figure.

      Then you factor in the ozone depletion, the various other high atmosphere problems high altitude jets cause, and the fact that those car journey we are comparing to are many times more polluting than bus/train commuting.

      747s are NOT environmentally friendly.

      If you want references try these:
      http://www.epa.gov/globalwarming/tools/ghg_calc. ht ml
      http://www.ans.neep.wisc.edu/~eic/personal.impac t. html
      http://www.rides.org/main/environmentalcalculato r. htm
      http://www.flightsciences.com/environ.htm
      http://www.climatechangesolutions.com/english/in di viduals/resources/default.htm
      http://ottawa2000.commuterchallenge.net/pollutio n. phtml

  6. Building a Hydrogren Fuel Cell? Semi-OT by redcliffe · · Score: 2, Interesting

    I'm about to begin constructing an electric car, and instead of using batteries which are heavy and expensive, I've been thinking about building a hydrogen fuel cell. Anyone know of some good web pages about that? Thanks,

    David

    1. Re:Building a Hydrogren Fuel Cell? Semi-OT by redcliffe · · Score: 1

      Um, no. That would be a methane fuel cell system. :-P

  7. Electric? by Komarosu · · Score: 3, Funny

    Eletric plane? what about a power drop? it needs a UPS i tell you :)

    --

    "What do you mean you have no ice? Do you expect me to drink this coffee hot?" - Random Customer, Clerks
    1. Re:Electric? by Anonymous Coward · · Score: 0

      >Eletric plane? what about a power drop? it needs a UPS i tell you :)

      What, so you'll have 15 minutes to land...or 15 minutes to kiss your butt goodbye.

    2. Re:Electric? by blazin · · Score: 1

      it needs a UPS i tell you :)


      Not to mention a really big-ass extension cord...

  8. boom? by Komarosu · · Score: 0, Flamebait

    Another thing...it gets hit by lightening and it will break the sound barrier :P

    --

    "What do you mean you have no ice? Do you expect me to drink this coffee hot?" - Random Customer, Clerks
  9. Hydrogen dangerous? by CheezWizFire · · Score: 4, Insightful

    Is hydrogen that dangerous? In a leak situation it quickly disperses and floats away right? As opposed to other fuels that will burn in an accident. I mean everyone dies in plan crashes anyways, I donlt think the survival record can get much worse. And if we all had secure hydrogen fuel tanks in a safe location in our cars and then I proposed that we instead carry around many gallons of flamable and explosive gasoline in thin tanks that rupture in accidents followed by the fuel spilling and flowing until it found a spark you would all call me crazy.

    -Steven

    1. Re:Hydrogen dangerous? by dido · · Score: 1

      Is hydrogen that dangerous? In a leak situation it quickly disperses and floats away right?

      Tell that to the passengers of the Hindenburg.

      --
      Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
    2. Re:Hydrogen dangerous? by rpjs · · Score: 0, Redundant

      IIRC the latest research suggests it was the flammable outer envelope of the Hindenburg that was primarily responsible for the disaster, rather than the hydrogen in the gasbags per se.

    3. Re:Hydrogen dangerous? by Captain+Pedantic · · Score: 1, Insightful

      It wasn't the hydrogen that burnt, it was the fabric of the skin. See here for details

      --

      None are more hopelessly enslaved than those who falsely believe they are free. Johann Wolfgang von Goethe.
    4. Re:Hydrogen dangerous? by Anonymous+DWord · · Score: 1, Redundant

      Why? It was the flammable fabric that burned.

      --
      "If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
    5. Re:Hydrogen dangerous? by DarenN · · Score: 2, Interesting

      I would like to point out that that fuek used is _liquid_ hydrogen, not gaseous like the hindenburg.

      It is extremely difficult to hangle due to the fact that it is stored at waaaaaaay below 0C. IIRC it isn't particularly flammable as it vapourises. Plus, the tanks it's stored in are pretty robust.

      --
      Rational thought is the only true freedom
    6. Re:Hydrogen dangerous? by Billly+Gates · · Score: 0, Flamebait
      If you look at the periodic table of elements, you will find hydrogen on the far upper left corner. If you remember from Highschool chemistry class, the further left and up you go, the more active the element is. Hydrogen is the most active element in the world. Its used ot make explosives because it can mix with almost anything and can make very unstable compounds that break easily. This makes a big explosion. Hydrogen also reacts with metal. This is bad because planes are made out of metal. Its just so reactive that it when it leaks it can react with just about anything and form explosive compounds. ALso by itself when its not in a compound it can explode quite nicely when heated up. Infact at my old highschool they put lye in the schools radiators. It turns out when natural acids in the water reacts with the metal, hydrogen gas can be created. Its so explosive that lye is added to prevent potential explosions from the boiler.

    7. Re:Hydrogen dangerous? by boltar · · Score: 0

      YOu need to go redo your chemistry because you're talking out of your rear end. Hydrogen isn't even
      close to being the most chemically active element in the world. Elements such as flourine and sodium
      are FAR more reactive. Hydrogen gas is only
      dangerous when mixed with oxygen and a source of
      ignition is present. If your argument was correct
      the outer gas planets would have exploded billions
      of years ago given that they're about 90% hydrogen
      each.

    8. Re:Hydrogen dangerous? by Grab · · Score: 2

      Keep up to date. 60 years back, in the investigation of the accident, they knew it wasn't the hydrogen that burned in the Hindenburg. Yet every time someone mentions hydrogen as a power source, some wazzock always brings up the Hindenburg as a reason not to do it. Just mark it down to "great urban legends of our time", I guess.

      Grab.

    9. Re:Hydrogen dangerous? by Grab · · Score: 2

      This post is entirely incorrect.

      In many chemical groups, the further _down_ the table you go, the more reactive an element is. So potassium is more reactive than sodium is more reactive than lithium. Nitrogen is top line and further left than oxygen, but nitrogen is significantly more stable than oxygen (drop lighted matches into tubs of oxygen and nitrogen, you'll find that the nitrogen one goes out while the oxygen one explodes). So don't trust Chemistry 101 to teach you everything you need to know about reactivity.

      Hydrogen is not particularly dangerous - no more so than any other flammable substance. The main problem is keeping it confined, since hydrogen molecules are very small and so hydrogen gas can migrate through slightly-less-than-perfect seals.

      Your problem in the school radiators is not due to it exploding due to ignition, but exploding due to pressure. You get a big build-up of gas in a sealed system, something's going to blow. Common sense, right?

      Oxygen also reacts with metal, and so do most other gases. But planes don't fall out of the sky bcos of this. And "creating explosive compounds" when reacting with the metal is just plain wrong.

      Grab.

    10. Re:Hydrogen dangerous? by Anonymous Coward · · Score: 0

      Kinda funny how the skin burned away faster than the hydrogen, and at a much different color than hydrogen burns too (yellowish orange, as opposed to hydrogen's blue flame). Maybe it's because the skin was covered with essentially solid rocket fuel (aluminum dust IIRC)? Will you trolls quit bring up the Hindenburg whenever someone mentions hydrogen? It's been disproved so many times its not even funny.

      Yes, hydrogen burns, but it's not C4, especially in liquid form. Aside from the currently expensive and heavy storage tanks, it's not much worse than gasoline.

    11. Re:Hydrogen dangerous? by mr100percent · · Score: 1

      Not everyone dies in plane crashes. Most of the recent fatalities seem to be Hijackings, small aircraft, and unexplained explosions on board.

  10. The airline industry wanted this for years by Billly+Gates · · Score: 5, Interesting
    This is definitely good news. Not for the technology or environment per say but for political stability in the middle east and terrorism. Ibet none of you have any idea of how much power the oil indistry has to suppress such research for years on in.

    The oil industry has such an effect in this country that its totally unbelievable (USA, for Europeans who hate American centered comments :-))! Basically they lobbied the FAA to make sure that fuel cell technologies for planes would never be approved. Boeing who is afraid of developing an engine that the energy-industry sponsored FAA would not allow them to sell, decided to only research fuel cell technology but not build any prototypes for obvious reasons.

    However the September 11 attacks changed this. I was within 2 or 3 blocks from the World Trade Center and it was not the plane attacks that brought the buildings down but over an hour of intense 2000F heat that melted the support beams. As much as 2 Olympic sized swimming pools of jet fuel went inside the 2 buildings. 200,000 gallons in total. I am amazed that the towers even stood for that long. I assume most of the 4,000 people who perished would of survived if it wasn't for the deadly fire and jet fuel. Many didn't make it out in time or the heat was so intense that the stairways actually melted where the fire was.

    Another problem we have is politics in the middle east. Americans have historically been strict isolationists. I would like it to stay that way. This all changed during both world wars and also during the rise of the oil industry. The 1991 gulf war was not about the suffering of those poor Kuwaiti's but for Exxon's, enrons, as well as Mobile's stock prices and profits. Bush senior received large amounts of money from the oil industry and we went to war to defend there interests and their cash. This is what started this whole Afghanistan mess we are in now. This is why China and the Arab world views Americans as empirialists. We represent more of the British empire in early America more then our original government. Our taxes now are actually much higher then before the American revolution! Believe or not. No wonder they view us as self serving empirialists. We actually are. Saudi Arabia is oppressive and the latest posts here on slashdot which state there intent to block internet access confirms this. We have no reason to support them other then for our energy interests. The sooner we lossen the oil industries grip the better. Also the Israeli's are being persecuted by terrorists groups funded by Arab's. I am aware the same can be said of the Palestinian persecution but when one group attacks another they both point fingers at each other and become more militant and oppresive. Before the 1950's the Arabs were all poor and lived in third world conditions. They ignored Israel before they had the money to fund Hummus. Thank oil for changing this. Anyway greed is bad and I am glad the government now is realizing that our dependence on foreign oil is bad. I believe fuel cell technology is the wave of the future for not only planes but cars as well.

    1. Re:The airline industry wanted this for years by Anonymous Coward · · Score: 0
      Anyway greed is bad

      yes. agreed.

      But the 10 minutes I used reading the rest of your post was a waste.

    2. Re:The airline industry wanted this for years by Rogerborg · · Score: 3, Insightful
      • The 1991 gulf war was not about the suffering of those poor Kuwaiti's

      Uh, the major cause of suffering for Kuwaitis has been the DUP's and unexploded ordinance dropped inside Kuwait by the good old US of A.

      I'm actually agreeing with your point, I'm just saying that there never was an ethical or moral motivation in the Gulf War. It was purely pragmatic: restore the regional balance of power, prop up a friendly dictatorship (sorry, "monarchy"), try out some new war toys, score a huge PR coup. And oil, oil, oil.

      --
      If you were blocking sigs, you wouldn't have to read this.
    3. Re:The airline industry wanted this for years by Anonymous Coward · · Score: 0
      Mod down. Not to label him as a troll or anything but for being over-rated. Just look at this guys spelling and grammer? Grrr. Where is the grammer nazi when you need him.

    4. Re:The airline industry wanted this for years by Monkeychunks · · Score: 0, Offtopic

      Ya. I thought Hummus was a dip made from chick peas ;)

      --
      "We kill to cure, with cures that kill" - Skinny Puppy
    5. Re:The airline industry wanted this for years by anshil · · Score: 1

      Look who is talking! First learn how to spell grammar :o)

      --

      --
      Karma 50, and all I got was this lousy T-Shirt.
    6. Re:The airline industry wanted this for years by boltar · · Score: 0

      I'd be pretty impressed if you could fit the
      entire contents of an olympic sized pool inside
      the wings of a 767. Unless they've borrowed
      technology from Dr Who's Tardis I think this is
      pretty unlikely don't you?

    7. Re:The airline industry wanted this for years by psychofox · · Score: 1
      200,000 gallons of fuel? Thats nearly one million litres! Or to put it another way approximately 1000 tonnes of fuel.

      I don't think so!

    8. Re:The airline industry wanted this for years by Billly+Gates · · Score: 2

      200,000 gallons /2 = 100,000 gallons. I got the numbers from a New York Times article. I use to clean swimming pools when I was a teenager. You could fit 80,000 gallons (average sized household pool) by a 50 foot by 15 feet with one half 2 feet deep and 8 at the other end. Thats around 3750 feet cubed.

      A 767 jet is a big plane. I guess several hundred feet long and I assume 15 feet wide with probably a 3 foot deep tank. Assuming the tank length is 200 feet that would equal 9000 feet cubed. Thats over twice the volume.

      I may know shit about airplanes but I believe its possible.A 767 is a big plane and I got my source from the the New York Times and CNN

      .

    9. Re:The airline industry wanted this for years by sunking2 · · Score: 2, Informative

      Well, you are a way off. Right off the Boeing web site there is a max fuel capacity of a little less than 24,000 gallons in all 767 models.

    10. Re:The airline industry wanted this for years by Anonymous Coward · · Score: 0

      That's 200,000 lbs (pounds)

    11. Re:The airline industry wanted this for years by Anonymous Coward · · Score: 0

      > They ignored Israel before they had the money to fund Hummus.

      I think you mean Hamas, Hummus is a middle eastern food made of chickpeas :)

    12. Re:The airline industry wanted this for years by Pyrosz · · Score: 1

      767's only hold 24,000 gallons of fuel (like others said), and all planes of that size store the fuel in tanks in the wings, not in the body of the plane.

      --

      An optimist believes we live in the best world possible; a pessimist fears this is true.
    13. Re:The airline industry wanted this for years by smithsb1 · · Score: 1

      I agree with most of what you said but you went a wee bit too far drawing links. Sure the arabs were fine with isreal in the 50's. But i think in the 60's when they were invaded by isreal that probably had more of an impact on fighting than oil money. The oil companies do control our daily lives but it's only cuz they pay for most of your presidents. If you want to stop this just ban fuel companies from making campaign donations and having lobby groups. (of course it's not the oil companies who are the greedy party, so that won't happen)

    14. Re:The airline industry wanted this for years by jpjma · · Score: 1

      "oil industry...lobbied the FAA to make sure that fuel cell technologies for planes would never be approved. Boeing is afraid of developing an engine that the energy-industry sponsored FAA would not allow them to sell"

      Where did you read such information? Could you please post sources? Those of us in the aviation industry find this a little shocking.

      "As much as 2 Olympic sized swimming pools of jet fuel went inside the 2 buildings. 200,000 gallons in total"

      Boeing 767 fuel capacity: 23,980 US gal
      156' x 56' regulation Olympic pool capacity: 485,000 US gal

      "I am amazed that the towers even stood for that long"

      The steel was insulated with a spray-on material, similar to concrete to survive a hot fire for one hour.

      "the stairways actually melted where the fire was"

      Where did you read this?

    15. Re:The airline industry wanted this for years by Anonymous Coward · · Score: 0

      Dammit! I meant what I said! They were too poor to afford chickpeas, much less weapons!

    16. Re:The airline industry wanted this for years by gutigre · · Score: 1
      Saudi Arabia is almost as repressive as the Taliban are/were, yet we call them an "ally" because we need their oil. About half our oil comes from the Middle East, and the percentage is expected to rise as environmentalists here block new drilling, for example, off the shore of Florida. If we weren't dependent on Middle-Eastern oil, we could try to create a few democracies there (in addition to Turkey and Israel) intead of supporting dictators.

      Fuel cells are not drastically more efficient than gasoline engines, and both require hydrocarbons at some point. The only way to slow the importing of Middle Eastern oil would be to adopt nuclear power on a large scale, and solar and hydroelectric power wherever possible. Maybe nuclear-powered cars and trucks aren't the answer, but there's no reason for us to be using oil or coal to power any device that can be plugged into the electric grid.

      Israel's issues have nothing to do with oil. Neither Israel nor any of the countries bordering it (Jordan, Lebanon, Syria, Egypt, or the Palestinians) contains more than a trickle of oil. The source of the conflict is, and was, that Arab governments blame all their social and economic problems on Israel instead of doing anything to fix them. The Arabs are STILL "all poor and [live] in third world conditions", but having failed time after time to destroy Israel in a real war, they choose terrorism, guerilla warfare, and the development of weapons of mass destruction as tools to destroy the "Zionist entity", as their leaders tell they arey are justified in doing.

      If any "imperialist country" is to blame for the state of the Arab world, though, it is the Ottomans. Until 1500 the Arabs possessed the world's most advanced society, but now all Arab countries are among the least developed, sometimes not far above sub-Saharan Africa. What exactly went wrong under the Turks is a matter for discussion, but Great Britain, France and the US have generally made thing better in most of the Middle East, except while supporting corrupt existing governments (as in Saudi Arabia now and in the Shah's Iran)... mainly to preserve our access to oil.

    17. Re:The airline industry wanted this for years by Trogre · · Score: 1

      I agree.
      Aside from the initial negative impact it would have on the current oil-centric economic infrastructure of the western world, it would be a huge benefit to be able to produce dead-dinosaur-free engines.

      Then we could tell the relatively few arabs that actually benefit from fossil fuel sales to go drink their oil.
      .
      .

      --
      "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
  11. Explosions & the environment by Master+Of+Ninja · · Score: 1, Interesting

    What about the risk of explosion in a fuel cell? Hydrogen is very volatile - you need a really good system that prevents tampering, leakage, electrical activity outside the plane, and can withstand crashes. I'm thinking about the Hindenburg airship disaster here when making comparison at the moment. I'm not an expert on these things so I would really like to know how the gas used in the auxiliary unit would "burn" in comparison to hydrogen in the event of a disaster. If it's just a safe (and maybe quieter) I wouldn't mind having it at as a power source - i mean it doesn't actually power the engines themselves so we should be quite safe.

    It's good to see that they are changing over to some environmentally friendly stuff. Most people have this stereotypical view that US companies are not very "green" - this might set them straight (although it's interesting that they've based the work in Europe...) Testing the fuel cell on cars would be a good idea as well - someone's probably already done this, but if hydrogen can be cheaply produced (cheaper than oil that is - nobody's going to change over to a new fuel source unless it is cheap) it should be an excellent fuel (practically no pollution).

    1. Re:Explosions & the environment by itarget · · Score: 1

      The amount of hydrogen in a fuel cell is a lot smaller than was in the huge bladders of the Hindenburg.

      It's also packed very tightly between "wafers" in the core of the cell. Leakage would take quite a bit of strucural damage; definately more than is required to puncture a conventional gas tank.

      I doubt it would survive a crash, but then I doubt any kind of large power source would survive a crash. I'd expect the fuel cell would flare up or jet fire, but not the roiling, plane-consuming fireball you usually get from conventional fuels.

      --

      "Where shall the word be found, where will the word resound? Not here, there is not enough silence." -T.S. Eliot
    2. Re:Explosions & the environment by nanojath · · Score: 2
      It would be nice if Slashdot had a memory, maybe we wouldn't have to have this damn "Hindenburg" conversation every time there's a story about fuel cells.


      So once again:


      1) A fuel cell does not necessarily mean a molecular-hydrogen based fuel cell. The Hydrogen - Oxygen to Water reaction is the most common but there are a huge range of potential molecular fuels.


      2) Even a molecular hydrogen based fuel cell need not rely on compressed gaseous hydrogen. There is tons of fruitful research going on to store hydrogen in solid substrates.


      3) Compressed hydrogen in tanks is not particularly dangerous compared to, say, liquid fuels. Mixture with oxygen tends to be a limiting factor in accidental combustion, and hydrogen disperses very quickly.


      4) Hydrogen was almost certainly not the cause of the Hindenburg explosion. Anyalysis of evidence makes a compelling case that the disaster was caused by the "doping" material used to treat the dirigible hull fabric, a combination of iron oxide, cellulose acetate and aluminum powder. A good brief article on the subject can be found at http://engineer.ea.ucla.edu/releases/blimp.htm


      5) Hydrogen as a fuel is not completely safe. Airplanes are not completely safe. Is it safe? No. Is it insurmountably and unacceptably more unsafe than conventional fuel vehicles? No. If it were, thousands of corporations would not be spending billions of dollars developing it. We call it common sense, people.

      --

      It Is the Nature of Information to Transgress Artificial Boundaries

  12. Tandential benefits. by karlm · · Score: 5, Interesting
    The biggest problem with fuel cells in airplanes should be the weight and bulk of the entire system. This is especially true for small aircraft. However, fuel cells provide many befets, especially compared to the piston engines used in sport aircraft.


    The article mentions that fuel cells are twice as efficient as heat engines. I thought the efficiency gap was larger. In any case, the laws of thermodynamics place an upper limit on the efficiency of a heat engine (such as a turbine or piston engine). This upper limit is known asw the Carnot efficiency. It is determined by the ambient temperature and the temperature of combustion. 30% is a decent estimate of the Carnot efficiency for a gasoline engine with the ambient temperature about room temperature. I thought fuel cells were about 80% efficient, but then again I'm on a coding break at 5 a.m.


    The MGM brushless DC motor developed at NTU in Australia has an efficiency around 99%.


    The main advantages of fuel cells for sport aviation are the extremely high efficiencies and the good reliability of the components. Electrical components and non-moving mechanical components have much higher reliability/cost ratio than their moving counterparts. I've held aircraft pistons with valves imbedded in them. Some people much prefer the Wankel rotary engine in aircraft for its simplicity. Turbines are much better in terms of reliability, but their cost is much higher. One should also consider maintenance costs. An aircraft piston engine typically needs to completely overhauled every 20,000 hours of operation to ensure reliability. Fuel cell inspection and overhaul involves many fewer parts and is probably much cheaper and probably needs to be done less frequently. The same should be true for electric motors.


    Another important factor in using electric motors is that the propellers can be designed more optimally if they don't have to deal with the large accelerations and decelerations that a 6-cylinder piston engine produces 3 times per revolution. Piston engines (even with flywheels) are very rough running, and propellers are beefed up so that they don't tear or shake appart under these loads. Any time you have to beef something up, you end up increasing the cost, weight, and/or innefiencies.


    Let's not forget that most sport aircraft require 110 octane "low lead" fuel that is expensive and releases polluting lead compounds into the environment.

    --
    Copyright Violation:"theft, piracy"::Anti-Trust Violation:"thermonuclear price terrorism"<-Overly dramatic language.
    1. Re:Tandential benefits. by FreeUser · · Score: 5, Informative

      An aircraft piston engine typically needs to completely overhauled every 20,000 hours of operation to ensure reliability.

      Very interesting post, but your decimal point is one off. My Lycombing O-360 (180 hp) engine has a TBO of 2000 hours, though I wish it were 20,000. :-) Airframes typically outlast multiple engines if they're well cared for, particularly if they're hangared (which mine is).

      When it comes time to overhaul or replace my engine I'd love to replace it with a hydrogen fuel cell system (which is far less explosive than 60 gallons of 100LL), assuming I could get comparable performance from it. Not likely, of course, but one can dream.

      --
      The Future of Human Evolution: Autonomy
    2. Re:Tandential benefits. by AnotherBlackHat · · Score: 1

      The article mentions that fuel cells are twice as efficient as heat engines. I thought the efficiency gap was larger.

      The article says they "can generate more than twice as much electricity with the same amount of fuel", however that's a bit misleading.
      Internal combustion engines produce mechanical energy. Fuel cells produce electrical energy.
      If the goal is to spin a propeller, then internal combustion engines have an advantage because they don't need a converter (the electric engine). If the goal is to produce electricy, then fuels cells have that advantage (no generator required.)

      Fuel cells also produce heat, which can sometimes be used, which is where those 80% effeciency claims come from. For example, if you're powering a home, then the heat from the fuel cell could be used to power the hot water heater (if it's a hydrogen fuel cell, you could vent the exhast directly into the hot water).
      If you don't use that waste heat, fuel cell effeciences are in the 40-60% range.

      Cars that run on ethanol fuel cells claim about 1.7 times the volume to power effecieny. Weight
      to power ratios are slightly higher. I'd expect a similar savings in aircraft, which means that a fuel cell airplane could travel a little under twice the distance with a full tank. Also, the fuel is cheaper, but as far as I know, the savings still are insufficient to overcome the enourmous costs of the fuel cells. This has improved a lot in the past ten years, but there still needs to be about another factor of 2 reduction in cost before they can compete.

    3. Re:Tandential benefits. by Anonymous Coward · · Score: 0

      20,000 hours what the hell kinda engine are you using. Its more like 2,000 hours TBO(Time Between Overhauls)

    4. Re:Tandential benefits. by smannell · · Score: 1

      As a pilot, I'd like to offer a few corrections. First of all, most piston aircraft engines need overhauls every 2,000 hours, not 20,000. While everone hopes fuel cells would last much longer than this, it is still difficult to say because there is very little real world data. Second, you are correct that propellers are heavier than they need to be, but it is my understanding that the main reason propellers are beefy is because they are also acting as a flywheel for the piston engine. Finally, although 100LL is still a very popular fuel; more and more people are using 90 octane mogas because it is cheaper. Most modern aircraft piston engines are capable of burning this fuel with little or no modifications.

    5. Re:Tandential benefits. by CodeShark · · Score: 1
      Several notes from an aircraft engine enthusiast in response to your points....

      In terms of weight and bulk, there are existing studies for aircraft designs that use fuel cells as the nighttime power source for high altitude unmanned missions during the night, with the hydrogen being provided from surplace PV electricity generated during daylight hours. Interestingly enough, PV efficiency was less critical to aircraft size and mission profiles than fuel cell weight, as you noted.

      The article mentions that fuel cells are twice as efficient as heat engines.

      Well, sort of. From what I have read, the top fuel cells are between 60% and 70% efficient when used in with a bottoming cycle to use the excess heat produced by the cell. Top (big) diesel engines are between 40% and 50%, turbines (jet fuel is similar to diesel and kerosene) can be anywhere from horrible up to nearly 60% (bigger newer = better efficiency). I have yet to read the specs for a gasoline fired production engine getting much more than 30%-35%, so a higher capacity fuel cell does pretty darn good compared.

      The critical thing to consider in terms of weight is that (depending on mission profile), if the engine is twice as efficient, you can carry half as much fuel. So even if the engine system weighs 60 pounds more (which would be make most general aviation engine designers shudder) for most general purpose aviation engines up to around 300-400 hp, for any flights requiring more than about 10 gallons of fuel, the overall aircraft weight would go down.

      As far as propellers, designs are pretty much optimizable already because the aerodynamic shape isn't generally affected by the engine pulses. What is being lost between pulses is a slight amount of rotational speed in the blade, so an electrical prop wth the exact same aerodynamic design should have a very slight performance advantage over a piston driven prop... provided that the electrical system doesn't add so much weight that the drag induced by the added weight doesn't actually increase the power requirements for the aircraft. Props are actually pretty good at turning shaft energy into thrust, btw, with a good prop providing about 85-90% of the shaft horsepower as thrust.

      Just my 2 cents worth. If I am wrong about any facts or figures, jump in and let me know... :-)

      --
      ...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
    6. Re:Tandential benefits. by bucky0 · · Score: 1

      Correct me if I'm wrong, but I thought that Carnot effiency had to do with Carnot engines, not just all heat-based engines.

      --

      -Bucky
  13. I meant tangential benefits by karlm · · Score: 1

    Hehe... forgot to proof read the subject line. It's 5 a.m. give me a break.

    --
    Copyright Violation:"theft, piracy"::Anti-Trust Violation:"thermonuclear price terrorism"<-Overly dramatic language.
  14. A couple... by itarget · · Score: 4, Informative

    ecosoul sells a fuel cell kit, and there are instructions (pdf) from homepower mag about how to construct one.

    --

    "Where shall the word be found, where will the word resound? Not here, there is not enough silence." -T.S. Eliot
  15. Zeppelin meets WTC by dirtyhippie · · Score: 0, Troll



    Hydrogen fuel in airplanes. Zeppelin meets WTC attacks. Great idea.

    Ha ha only serious.

    -DH

    1. Re:Zeppelin meets WTC by Billly+Gates · · Score: 2, Insightful

      Actually the wtc would survive. It was the intense heat of the jet fuel and not the explosion which brought it down. This is why alternative fuel cell technology is bieng developed. Also not all fuel cells use hydrogen.

    2. Re:Zeppelin meets WTC by maroberts · · Score: 2

      The Hindenburg was erroneously responsible for the end of the use of hydrogen as a means of propulsion or lighter than air vehicles for a long time.

      It is only recently [last 15 yrs?] that it has been realised that the main cause of fire on the Hindenburg was the coating on the fabric, which contained powdered aluminium amongst other things, and was remarkably similar to rocket fuel and thermite explosives!

      The hydrogen fuel in the Hindenburg simply burnt and escaped upwards and was not really responsible for any deaths in the incident. Even so IIRC about 2/3 of the people escaped, which is more than be said for current day aircraft incidents.

      If such a craft did ram a large building, the fuel would burn off/escape quickly and be unlikely to generate the intense fires generated by aviation fuel in the WTC attack. Even better, the burning fuel would not run down inside the building, setting fire to multiple floors.

      --

      Donte Alistair Anderson Roberts - hi son!
      Karma: Chameleon

    3. Re:Zeppelin meets WTC by shogun · · Score: 1

      If such a craft did ram a large building

      Wouldn't it just bounce off anyway? *has images of hijacked zeppelins richoetting off various buildings in NYC*

    4. Re:Zeppelin meets WTC by maroberts · · Score: 1

      Lighter than air craft can have solid skins either in total or in part, and even if it didn't if the craft exploded right next to the building it could cause damage. Anyway I think even a soft skinned vehicle wouldn't bounce if it was going fast enough.

      Anyway I think the original poster was also considering the possibility of heavier than air hydrogen powered craft too.

      --

      Donte Alistair Anderson Roberts - hi son!
      Karma: Chameleon

    5. Re:Zeppelin meets WTC by Anonymous Coward · · Score: 0

      Beep beep beep!

      Faulty sense of humor detected!

      Report to your nearest maintenance center to have the stick pulled out of your ass!

      Beep beep beep!

    6. Re:Zeppelin meets WTC by mikerich · · Score: 1
      Ummm...

      The Addison Bain theory for the burning of HINDENBURG is in no way proven. Whilst it makes a convincing case when read alone, it is less good when considered in context.

      Firstly, the aluminium powder was not novel, it had been used in the dope of airships by the British in 1911 and had been included in most airships since the end of World War II - including on GRAF ZEPPELIN and all the US Navy airships. It was never linked to the destruction of any ship.

      Secondly, the operators of HINDENBURG were quite familiar with the properties of the cover. The ship used heavy diesel engines which had a habit of spitting out large chunks of hot carbon that had accumulated in the exhaust. The carbon would scorch or even burn through the cover - but it never ignited.

      Bain was right the ship would have burned long before she did.

      At the end of the day, the peculiar characteristics of the disaster make it most likely that HINDENBURG was destroyed by sabotage. After all, it's hardly as if she was coming from a popular country and threats had been made against her in the past.

      Best wishes,

      Mike.

    7. Re:Zeppelin meets WTC by mikerich · · Score: 1
      Oops - overediting.

      Should read:

      If Bain was right the ship would have burned long before she did.

      Apologies.

      Mike.

    8. Re:Zeppelin meets WTC by maroberts · · Score: 1

      Nope, it's a semi serious question asked by someone with a low userid number. Anyway, the whole thread has a sense of baclk humour in it, so why should answering this one be any different?

      --

      Donte Alistair Anderson Roberts - hi son!
      Karma: Chameleon

  16. Gasoline Fuel Cells by Vidmaster_Steve · · Score: 1
    I remember reading somewhere some six months ago (maybe SciAm, maybe /., can't readily remember) an article that stated that a gasoline-powered fuel cell would be far more efficient than those that derived their power from water/distilled hydrogen.

    Now, I can see how a gasoline fuel cell could prove more effective than one that runs off of water/hydrogen/methanol. Pound-for-pound, gasoline produces far more energy than hydrogen, and is more cost effective than methanol.

    But... I'm not exactly certain on the intricate workings of the fuel cell, so I'm not certain if the gasoline fuel cell is feasable, or if it's just a scam perpetrated by the oil companies to perpetuate their stranglehold on the transportation industry?

    Now I can totally not wait for little tiny nuclear reactors under the hood... mmmm, efficient electric cars... Too bad it'll never happen though...

    --
    Why is it when I hit ^R that ZSH calls me a cocksucker?
    1. Re:Gasoline Fuel Cells by redcliffe · · Score: 1

      Is there any fuel that can be used in a closed loop that has a better efficiency than hydrogen and oxygen? I want to be able to plug my car into a power point to charge it up, not fill it with gas. Thanks,

      David

    2. Re:Gasoline Fuel Cells by ebichete · · Score: 1

      Now, I can see how a gasoline fuel cell could prove more effective than one that runs off of water/hydrogen/ methanol. Pound-for-pound, gasoline produces far more energy than hydrogen, and is more cost effective than methanol.

      "Pound-for-pound" ??
      Are you sure you don't mean "Litre-for-litre-at-room-temperature-pressurized-t o-atmospheric-at-sea-level"? Hydrogen compresses significantly with ease. This gives it a "Pound-for-pound" greater than most fuels.

    3. Re:Gasoline Fuel Cells by Anonymous Coward · · Score: 2, Informative


      Now, I can see how a gasoline fuel cell could prove more effective than one that runs off of water/hydrogen/methanol. Pound-for-pound, gasoline produces far more energy than hydrogen, and is more cost effective than methanol.


      No no. Liquid hydrocarbon fuel (gasoline) holds 45 Megajoules of energy per kilogram. Hydrogen packs 129 Megajoules with the same weight. It is also much more efficient to burn. The problem is hydrogen is gaseous so it takes a lot of space. You need to build a strong storage unit and enormous amount of energy to compress em.

      Gasoline molecule does not work on proton-exchange membrane (PEM) so gasoline powered fuel cell is a misnomer. What they might be saying is extract the hydrogen from the gasoline using a reformer. The hydrogen is then used in the fuel cell unit. So you actual need to separate units, the fuel cell and the reformer.

      Ford is currently building a fuel cell vehicle. Right now we could not find a supplier who build an efficient reformer so we opt for direct hydrogen. Once somebody comes out with a good reformer and a good fuel cell, we'll all be using fuel cell technology.

      Later,

      A guy working at Ford.

    4. Re:Gasoline Fuel Cells by Dyolf+Knip · · Score: 2

      "Pound-for-pound" ??
      Are you sure you don't mean "Litre-for-litre-at-room-temperature-pressurized-t o-atmospheric-at-sea-level"? Hydrogen compresses significantly with ease. This gives it a "Pound-for-pound" greater than most fuels.


      He meant pound for pound. The mass doesn't change with temperature, pressure, altitude, or zodiac sign. How well it compresses has nothing to do with it's energy density by unit mass.

      And no, H2 doesn't compress easily, at least not to anything really useful. The parent was right, pound for pound hydrogen has 3 times the energy density of gasoline. But it can't be compressed to anything like the mass density of gasoline. Even as a liquid it's only 1/10th as dense. And liquifying it is no answer, it takes several times the energy you get from combusting it to cool it to that point.

      --
      Dyolf Knip
  17. Electric powered aircraft by mactom · · Score: 5, Informative

    Hi,

    There are already several electrically powered aircraft flying. Ok, most of them are gliders that use the engine for take off and then retract it and continue flying, gliding and gaining altitude in thermals. But there is already a powered glider, the icare, which uses solarcells to power an electric motor for take off and sustained cruise.

    Take a look at the following websites:

    Lange Flugzeugbau
    Icare
    Silent AE1

    Conventional self launching gliders are already very sophisticated, but the engines they use, require a lot of maintenance and are sometimes not as reliable as you might wish. Well anyway, if the engine fails I land on a field, no problem there, ... that is if a field is in range. Electric engines should increase reliability quite a lot. Hopefully they are available soon.

    Regards, Thomas.

    1. Re:Electric powered aircraft by kryzx · · Score: 2

      There is also Helios, a high altitude unmanned aircraft powered by solar and fuel cell and designed to stay in flight for days or months. Could be used as an "atmospheric satelite."

      --
      "I don't know half of you half as well as I should like, and I like less than half of you half as well as you deserve."
  18. first plane then elec. Re:Tandential benefits. by leuk_he · · Score: 1

    ``Our ultimate goal is to replace the auxiliary power unit,'' said Dave Daggett, associate technical fellow in the environmental performance strategy group. ``But first, we're going to learn more about fuel cells by powering a small airplane

    I think it is a strange route they take. To have it for the power unit (i suppose the electrical generator) they first power a plane with it.

  19. Brief Lesson On Hydrogen Safety by Self+Bias+Resistor · · Score: 5, Informative

    What about the risk of explosion in a fuel cell? Hydrogen is very volatile - you need a really good system that prevents tampering, leakage, electrical activity outside the plane, and can withstand crashes. I'm thinking about the Hindenburg airship disaster here when making comparison at the moment. I'm not an expert on these things so I would really like to know how the gas used in the auxiliary unit would "burn" in comparison to hydrogen in the event of a disaster.

    Flammable fuels are only explosive when it has mixed with air in a sufficient quantity to form a fuel-air mixture. This is different from volatility, which is a measure of how easily a compound turns into gaseous form (petrol/gasoline, for example, is quite volatile, as is ethanol). The fact is that Hydrogen is the lightest element on the periodic table and hence diffuses through leaks and openings much more quickly than, say volatile fumes from regular petrol or JP9 jet fuel (where the fumes consist of multiple gaseous hydrocarbons, which have greater molecular weights and are hence much heavier). This is why there is no gaseous Hydrogen in the Earth's atmosphere. The Hydrogen simply floats away into space.

    If you were to be involved in an accident involving an aircraft equipped with a Hydrogen fuel cell, you'd find that the chief cause will not have been the Hydrogen. The combustion of the fuel used in the aircraft's engines (remembering that the Hydrogen fuel cell will be used as a backup device to generate air and power for the aircraft and not as a means of propulsion) would have caused the lion's share of the damage. The only noticeable effect the Hydrogen would have on the acccident is to perhaps allow the fire to burn a little longer (assuming that enough of the Hydrogen is still contained in the air and has not diffused into the atmosphere). When being used in fuel cells, Hydrogen chiefly stored as a compressed, possibly liquefied gas. Hydrogen can also be stored in certain metallic compounds (known as metallic hydrides, which hold the Hydrogen atoms in a similar way to amalgum containing Mercury) to increase energy densities. In the first case, the rapid diffusion of the Hydrogen gas would not cause a fire for the reasons outlined above. In the second case, the Hydrogen would not be released because it is still bound to the metallic hydrides. In either case, it is unlikely that the cause of the accident will be the Hydrogen fuel. Hydrogen has, in fact, been proven to be a safer fuel to handle than gasoline. The byproduct of the fuel cell is water vapour, so it's also much better for the environment.

    Your comparison to the Hindenburg disaster is not really applicable in this case, as it was conclusively demonstrated that it was the Aluminium compounds in the paint on the Hindenburg that caused it to burst into flames and not the Hydrogen gas. The Hydrogen ignited later, burning much more slowly and for a lot longer and hence actually acted as a fuel that sustained the fire, as opposed to the agent that caused the ship to burst into flames in the first place (remembering that the ship still burned even though the outer material had been completely destroyed).

    --

    ----------
    When the pin is pulled, Mr. Grenade is no longer our friend.

  20. Duh by autopr0n · · Score: 1

    Storing solar power in the form of brown's gas (hydrogen oxygen mix 2:1 mix) is moronic. Just use a battery; you're not going to get that much energy from the sun. Electrolysis and combustion (even chemical with a fuel cell) is going to be really inefficient.

    --
    autopr0n is like, down and stuff.
    1. Re:Duh by Grab · · Score: 2

      Duh-squared. Who mentioned getting energy from the sun? Say it with me again, "Fuel. Cell." Hydrogen is stored in tanks, ready for use. Solar panels are completely absent.

      Grab.

    2. Re:Duh by Drakin · · Score: 1

      Exaclly. There was no mention of the use of Solar pannels in the story.

      So why do people think of enviromentaly friendly technologies have to all rely on Solar Panels?

      Do you have to invest energy to create Hydrogen and Oxygen? Yes. Does it have to be Solar? No, not really. We also can produce electricity through tidal power, and wind power. True these sources aren't entirely relyable (unless you happen to be in a nation's capital, wind and hot air is always in excess there) but they'd do the trick, expecially if there were more advances made in those areas.

    3. Re:Duh by Dyolf+Knip · · Score: 2

      Electrolysis and combustion (even chemical with a fuel cell) is going to be really inefficient.

      And ordinary chemical batteries are the pinnacle of efficiency? You're lucky if you get a tiny fraction of what you put into them back out. Not to mention they are usually highly toxic and have to be thrown out every few years. Using H2 to store energy has the potential to be much more efficient, resuable, clean, and lightweight than a corresponding set of chemical batteries. It's not right now, mostly due to problems with storing the H2, but so what? Our solar cells suck too, does that mean they'll never be any good?

      --
      Dyolf Knip
  21. Thats not what he was talking about by autopr0n · · Score: 2, Insightful

    He said the Cells were dangerous. Not the fuel itself. That's like asking if an IC engine design is 'safe' and we know it is, since we can regulate the flow well. When was the last time a car engine (not gas tank) just blew up?

    --
    autopr0n is like, down and stuff.
    1. Re:Thats not what he was talking about by Anonymous Coward · · Score: 0

      Last month. Car blew a cylendar right through the hood.

  22. Environment Friendly Flying by dhart · · Score: 3, Interesting

    This is Fantastic!

    I fly regularly between Australia and the US. I would gladly extend the duration of the already long trip (14 hours) for the trade offs:

    o Environmentally Friendly (by a large degree)
    o Quieter

    With longer fight times and lower fuel carrying requirements, hopefully these new planes would become more passenger friendly as well (no more deep vein thrombosis). If there's a bar and a free Internet connection, I have no problem spending 24 hours on a plane!

    1. Re:Environment Friendly Flying by Iamthefallen · · Score: 1
      I have no problem spending 24 hours on a plane!

      I do, sooner or later night falls, that's a bad time to be in a solar powered airplane 10k ft over the pacific

      --
      Wax-Museum Fire Results In Hundreds Of New Danny DeVito Statues
    2. Re:Environment Friendly Flying by Lord+Hugh+Toppingham · · Score: 0
      But surely the thing will have rechargable batteries on board to store the solar energy during the day, to release it at night ?

      -- Are you a Linux Zealot ?

    3. Re:Environment Friendly Flying by rfreynol · · Score: 1

      Quiter is definitely better - you don't want noise pollution from a plane at 35k feet disturbing the fish in the Pacific ocean.

      :)

    4. Re:Environment Friendly Flying by Anonymous Coward · · Score: 0

      You stupid fuck, it's a fuel-cell powered plane, not solar-powered.

  23. Noise Reduction the Really Big Gain by Anonymous Coward · · Score: 0

    Folks living near Chicago O'Hare have been noticing that they don't hear the airport since September 11th. Why? The local airlines have mothballed their oldest planes, namely the 727's, which are the noisiest, even with the new "hush" kits installed.

    During the summer, my home is continually harassed by light plane enthusiasts who have old, completely unmuffled piston engines.

    I won't be sad to not hear airplane traffic. Can't come soon enough for me.

  24. Hydrogen doesn't explode � by Selur_Natas · · Score: 2, Informative

    The heisenburg exploded because it was painted with reactive metal paint.
    Static discharge in the atmosphere caused the explosion with flames you can see.

    Hydrogen burns in UV frequencies, you can't see it.

    --
    . Mankind evolved from apes, JonKatz is still a baboon.
    1. Re:Hydrogen doesn't explode � by steve_bryan · · Score: 2, Funny

      We're still uncertain if the Heisenberg exploded. On the other hand the Hindenberg did have an explosive demise.

  25. New Fuel Cell Applications Good by cyberlync · · Score: 2, Insightful


    Good Lord people, stop talking about how impossible it is an welcome it as a good thinng. If nothing else then it will, at the very least, foster some additional research into a promising area of clean, renewable energy sources. At the best they come up with a light, clean, cheap, powerfull fuel cell that could have applications in many other areas. Its a win win situation for everyon except boing (if it fails it could lose money). Any way even if it is impossible that just makes it more attractive. Since when did progress rely only on what was possible?

    --
    I'm a programmer, I don't have to spell correctly; I just have to spell consistently
  26. Did ANYONE bother to read the article? by John+Harrison · · Score: 5, Informative
    From the article:

    Fuel cells and electric motors will not replace jet engines on commercial transports, but they could one day replace gas turbine auxiliary power units. Auxiliary power units, which typically are located in the rear fuselage with exhaust ports through the tail, are coupled to generators and compressors to produce electricity and air for airplane systems while on the ground and for backup use in flight.

    Let me repeat, they are NOT trying to use fuel cells to replace the jet engines. They are going to use them to replace auxilary power units, which simply produce electricity.

    So basically, this entire discussion here on /. is about the wrong thing! Not only is it about the wrong thing, but the thing that has been announced isn't that big of a deal. These are not electric aircraft that they are producing!

    So move along now, the really is nothing to see here.

    1. Re:Did ANYONE bother to read the article? by Wyatt+Earp · · Score: 3, Informative

      Fuel Cells to replace APUs would be a Good Thing for civil and military aviation.

      Some of the APUs for aerospace use nasty chemicals like Hydrazine. Replacing those APUs with a fuel cell (The Shuttle uses a combination of APUs and Fuel Cells) would make the planes alot safer for mainatance people.

    2. Re:Did ANYONE bother to read the article? by DaoudaW · · Score: 3, Insightful

      Of course I RTFA! And I almost wrote a comment like yours, but

      Boeing Commercial Airplanes will develop and test an electrically powered demonstrator airplane,

      so they are building a plane. It looks to me like they are setting the bar low. No, I don't expect them to come out with a fuel-cell powered business jet, that wouldn't be possible would it, but they are exploring environmentally friendly fuel cell technology for future Boeing products. Note the plural.

      The exciting thing about this announcement is that a sector which uses huge amounts of fossil fuel is looking into environmentally sound alternatives!

    3. Re:Did ANYONE bother to read the article? by John+Harrison · · Score: 2
      You selected the most misleading sentence of the whole article:

      Boeing Commercial Airplanes will develop and test an electrically powered demonstrator airplane, They are making a demonstration plane that has a propeller that is powered by fuel cells. However, this NOT the goal of their project. And as you stated this is not going to lead to fuel-cell powered jumbo-jets. Once again from the article:

      ``Our ultimate goal is to replace the auxiliary power unit,''

      and

      ``Fuel cells show the promise of one day providing efficient, essentially pollution-free electrical power for commercial airplane primary electrical power needs,''

      Now I agree that this is great, but everyone seems to be running around thinking it is something that it isn't.

  27. congrats Boeing, you're SECOND by mr.ska · · Score: 5, Interesting
    A fuel cell-powered airplane is being worked on. Admittedly, it's not an airliner, but it's still the same problems, just on a smaller scale.

    EVWorld.com has the two-part story and interview with the plane's builder here (1) and here (2).

    --

    Mr. Ska

    1. Re:congrats Boeing, you're SECOND by waltal · · Score: 1

      You know, don't you, that the aircraft industry invented vaporware first? The EVWorld article contains plenty of information to reveal that fact. I am still looking for a 180 HP electric motor that doesn't require a crane to pick up.

      On the other hand, I've held a compressed-air motor in one hand that produced 200 HP. I wonder why nobody is looking into compressed-air power?

      Could it be that you have to lift the whole system in your airplane?

    2. Re:congrats Boeing, you're SECOND by sysadmn · · Score: 1

      A fuel cell-powered airplane is being worked on. Admittedly, it's not an airliner, but it's still the same problems, just on a smaller scale.

      Size matters. Even if it worked perfectly for a small aircraft, it wouldn't be right for an airliner. The article discusses a 10-15kW fuel cell; a low-to-mid range jet engine is in the 20-40MW range. Even assuming you could scale up the fuel cell 400-fold, could you do it without scaling up the weight of the system (and fuel storage system) 400-fold? As an APU, this would be wonderful, especially if it's the electricity you're looking for. As a propulsive force, especially for a large aircraft, you're pretty limited (i.e., subsonic speeds, prop noise, duration, etc).
      --
      Envy my 5 digit Slashdot User ID!
  28. In Principle, yes... by hotgrits · · Score: 0, Offtopic
    The heisenburg exploded because it was painted with reactive metal paint.

    I'm a little uncertain that you've got the right name here.

    1. Re:In Principle, yes... by hotgrits · · Score: 2, Funny

      Offtopic? Sheesh. Make a joke and it goes over like a lead zeppelin.

    2. Re:In Principle, yes... by Anonymous Coward · · Score: 0

      Holy crap, stupid moderators... +1 Funny should be stacking up on this post, not a bloody -1: Offtopic.

      Pull your heads out of your asses and recognize a great joke when you see one!

  29. Ka-BOOM! by tenzig_112 · · Score: 0, Flamebait

    The Hindenberg disaster meets 9/11- that's what we may very well get when we combine hydrogen-based fuel cells with air travel. Only this time it won't be terrorism but some minor maintenance foul-up that kills thousands of people.

    Why not put wings on nuclear submarines?

    Fuel cells, high-def TV, Linux: they all make so much sense, if only we could manufacture enough consumer interest...

    1. Re:Ka-BOOM! by zephc · · Score: 1, Offtopic

      C'mon, are you trolling?

      The Hindenburg burned so well because it was painted with a paint that is very similar to rocket fuel.

      Airplane fuel is also much more dangerous than the Hindenburg was (as we have seen).

      --
      "I would say that 99 per cent of what my father has written about his own life is false." - L. Ron Hubbard Jr.
    2. Re:Ka-BOOM! by zephc · · Score: 2


      Offtopic, me? Suh, I DEMAYAND satisfaction! O at least that you READ what I wrote!
      Yo' trollin' and flaaaamebaitin' has dragged MAH own kahmah down with YOWAHS!
      <slaps-with-glove/>
      </southern-gentlemans-voice>

      --
      "I would say that 99 per cent of what my father has written about his own life is false." - L. Ron Hubbard Jr.
  30. Solar Cells by Spudley · · Score: 5, Insightful

    I've always thought that aircraft wings are one of the most obvious places to put solar cells. On a day-time flight, you're practically garuanteed maximum sunshine for the whole duration.

    Even if you don't use it directly to power the engines, there's still plenty of electronics on your average aircraft that could use it.

    --
    (Spudley Strikes Again!)
    1. Re:Solar Cells by Wyatt+Earp · · Score: 1

      On a small civil air craft like the story is talking about, you're not always going to get sunshine for the whole flight.

      It's much more efficent to power your avionics with a wind driven turbine that hangs outside the plane (like the jammer EA-6 use) or from an alternator off the engine.

    2. Re:Solar Cells by rfreynol · · Score: 1

      Except that on commerical airliners, the wings also contain 100K+ gallons of fuel. Do you really want to put an electrical generating system in such a close proximity to all that jet-a?

      Also, if you deduct the area of the wing that is comprised of moveable surfaces (ailerons, flaps, air brakes, slats) the top surface of the wing is relatively small. The top of the fuselage would be a better place to put solar panels.

      I would guess that a air powered turbine would produce more electricity than solor panels; it it would induce some drag, but as long as the plane is flying, it works - unlike solar panels which won't work at night, on overcast days or when flying IFR.

    3. Re:Solar Cells by Anonymous Coward · · Score: 0

      The problem is that the surface of the wing has to do the lifting. The solar cell either has to be smooth enough and strong enough to produce and sustain the lift required to keep the airplane aloft, or it has to be small enough not to interfere with the production of said lift by a more conventional material.

    4. Re:Solar Cells by Anonymous Coward · · Score: 0

      "Do you really want to put spark plug wires in your car near all that gas? it may explode."

      It amazes me the stupidity of people on this site. Especially you. You need shot.

    5. Re:Solar Cells by BigBir3d · · Score: 1

      "Lifting" as you call it, is a stress on the underside of the wing, and the on airframe where the wing joins the fuelselage. The biggest worry for the solar cells on top of a wing is air turbulence. The suction of air above the wing, as well as wind shear (winds that are not in parallel to the direction of travel.

      It is really just a matter of adhering them to the wing, making them aerodynamic, and keeping them clean.

    6. Re:Solar Cells by CodeShark · · Score: 1
      I thought so to. Until I realized that when you consider the efficiecy of the PV cells, it takes a great big set of wings to generate even the equivalent of 10 horsepower/hr. During the day. During the summer. (unless you can afford the best ones -- which are worth well more than their weight in gold...)

      By the time a non -charged piston engine is up to about 8000 feet, it's lost about 20%-30% of its original sea level power, IIRC, so about the best use I've come up with for PV cell power so far would probably be for turbo and or light supercharging so that the damn fuel hogging engine up front gets more O2 to burn as the aircraft goes higher. Since drag goes down as the plane goes up, this would be a good thing in terms of fuel economizing. Still leaving more than enough extra extra engine power for the instruments, I think.

      Thoughts anyone?

      --
      ...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
  31. Personal Air Crafts by zephc · · Score: 2

    I've been playing around with the idea of a Moller Skycar-like personal aircraft with super-simple computer-aided controls (accel, decel, left, right, up, and down, plus GPS assistance), and it occured to me that a fuel-cell powered propultion system would be VERY sweet, but maybe not practical for a few years (a few very short years, based on their swift progress! =])

    --
    "I would say that 99 per cent of what my father has written about his own life is false." - L. Ron Hubbard Jr.
  32. The question is... by Hellen+Back · · Score: 1
    "The question is can a fuel cell deliver enough energy for a flight long enough to be practical."
    The question is will you be able to recharge with California's energy problems?
  33. You are just plain loony by Benjamin+Shniper · · Score: 1

    1. Fuel cell technology won't do much to change our dependance on oil. Oil is the major source of combustable carbon and hydrogen, which are used in Fuel cells.

    2. Fuel cells have been off the market because of expense, expense, and expense. Only recently has the price gone down.

    3. Greed is good.

    4. Isolationism helped cause World War II and the great depression (see the trade barriers put up the week before the market crashed), and kept the United States from interfering in a war which threatened all our allies and ourselves as well.

    -Ben

  34. *groan* by Anonymous Coward · · Score: 0

    that was bad, really bad.

  35. Different types of Fuel Cells by ArhcAngel · · Score: 3, Interesting

    Many of the posts alude to the potential of a hindenburg type explosion on a plane that used such a fuel cell system because of the Hydrogen involved. According to the article Boeing is looking at using fuel cells but it doesn't specifically mention hydrogen fuel cells except to say one was seen used in an automotive demonstration. There are many different types of fuel cells http://www.fuelcells.org/fctypes.htm each having it's pros and cons. I do see a move to "alternative" types of fuel but, as always, economics will drive the shift as much as anything else. Right now energy companies are scrambling to figure out how to profit long term on systems that are so efficient. Anyone old enough to remember when an automobile wouldn't go over 75,000-100,000 miles without a MAJOR overhaul? It wasn't because they couldn't be more reliable but becaue the big 3 made $$$ off of the repair parts as well as new car sales. If the Japanese companies hadn't offered more efficient/reliable products in the 70's we might still be seeing the trend.
    OK, I think I sufficiently wandered off topic

    --
    "A person is smart. People are dumb, panicky dangerous animals and you know it." - K
  36. Energy density problems? by michael_cain · · Score: 3, Informative
    Early in October the subject of hydrogen-powered airliners was discussed. The primary problem pointed out was not explosion, but the low energy density of even liquified hydrogen. I believe someone worked it out and that a New York to LA flight required filling the entire interior of the plane -- cargo space, passenger cabin, etc -- with liquid hydrogen to have enough fuel for the flight. Assuming fuel cells to produce electricity to drive efficient motors to drive big props are twice as efficient as just burning the hydrogen in a jet, low energy density is still a serious problem.

    As others have suggested, if I could just invent a fuel cell that dealt handily with carbon- and nitrogen-rich fuels, I could help the environment and get rich.

  37. Great Bang! by Anonymous Coward · · Score: 0


    Fuel cells are cool. Just imagine how big the ball of WTC fire would have been if it was hydrogen instead of jet fuel...

    Crispy, crispy, crispy.

  38. Re:hydrogen must be stored at large pressure by guybarr · · Score: 1

    IAN an Aircraft Engineer but IIRC, for high energy density you need to store the hydrogen gas at very high pressures (a gas at the density of a liquid), which causes an immediate explosion once you have any sort of crack.
    This is not so in other fuels, which are liquids and so are very dense at normal atmospheric pressure. A leak in such a container is still dangerous, but after some time, when fuel vapours ignite.
    Oh, and BTW, for an aeroplane you need much higher MTBF (Mean Time Between Failure) than for a space mission; there are a lot more air flights than space ones.

    --
    Working for necessity's mother.
  39. WTF are you talking about? by autopr0n · · Score: 0, Flamebait

    The FUEL exploded not the fucking engines!

    It dosn't matter what method of extracting energy was used, what matters is how it's stored.

    --
    autopr0n is like, down and stuff.
  40. Enough with flying already. by kiddailey · · Score: 1

    When are we going to start seeing more R&D of teleportation? Let's break some laws already!

  41. Makes a lot of sense by AJWM · · Score: 3, Informative

    The question is can a fuel cell deliver enough energy for a flight long enough to be practical.

    The answer is, "yes".

    Fuel cells are very efficient at converting chemical to electrical energy -- the cells NASA has been using on manned spacecraft since the 1960s run at about 75% efficient -- compare that to the roughly 30% efficiency of a combustion engine. (Although for a proper comparison we'd also need to factor in the efficiency of the electric motor. At 85%-90% (numbers I've seen quoted) that gives a net chemical-to-mechanical efficency of about 64%-67%.)

    As far as safety goes -- well, NASA has been running H2-O2 fuel cells on manned spacecraft since Gemini, and the only problem they've ever had with that system was due to a combination of spec changes and improper procedures causing an O2 tank to explode (Apollo XIII).

    --
    -- Alastair
    1. Re:Makes a lot of sense by Weaselmancer · · Score: 1

      ...and it's worth noting that ALL of the Apollo XIII astronauts made it home safely after the explosion. And the astronauts were sitting on top of pretty much the most dangerous fuel cell you can make, high-pressure liquid oxygen and liquid hydrogen. In a vacuum. In zero G. Not only did they live, but the system still partially functioned!

      Just a small something for all of the WTC/Hindenburg/Hydrogen-is-dangerous posters to think about.

      --
      Weaselmancer
      rediculous.
  42. Modern fuel cells use alcohol to produce hydrogen by SysKoll · · Score: 3, Interesting

    Everyone here is assuming that the fuel cell based auxiliary generator discussed in the article will be using hydrogen.

    Actually, a lot of work is being done on fuel cells burning alcohol (ethanol). Either you use a cracking step to produce hydrogen on-the-fly by decomposing the alcohol molecule with a catalytic grid, or you use a pretty fancy membrane to rip the hydrogen directly from the alcohol molecule.

    Either way, you don't need to carry a hydrogen tank. So save the Hindenburg references for a more appropriate topic.

    Since alcohol is actually less energetic per kilogram than kerosen, I don't see why it would be dangerous. The only problem is that it's one more fluid to carry in airports, and that would probably require even more work and red tape than getting an alcohol-burning fuel cell approved by the FAA.

    The residue of such a fuel cell is alcohol remains mixed with water and various catalytic by-products. In other terms, watered-down alcohol with metalic salt traces and a few moderately toxic molecules. Not very dangerous either. Heck, with a bit of luck, airlines will decide to tap this residue and sell it to passengers in lieue of the horrible Californian el cheapo wine they serve with meals. :-)

    --SysKoll
    --

    --
    Mad science! Robots! Underwear! Cute girls! Full comic online! http://www.girlgeniusonline.com/

  43. petroleum dependency by oomcow · · Score: 1

    saw some article on tv stating that the u.s. actually only gets 10% of its oil from the middle east anyways (like 50% domestic, 10% mexico, 10% canada, 10% venezuela, 10% other, 10% middle east or something like that.). the television article pointed out that our buddies europe and japan get much more of their oil from the middle east, so that's sort of why we end up sticking our noses into the middle east conflicts.

    as for that comment about our taxes being higher than before the american revolution, our current taxes are still lower than the current taxes in britain (as time has progressed, both governments have begun to provide more services). =)

    1. Re:petroleum dependency by sonic2 · · Score: 1

      I believe that was on Nightline about a week ago, and your percents look right. Japan was quoted at 60+% and Europe at 35+% dependence on Middle East oil.

      On NPR I heard a quote stating that we get about 20% from the Middle East, and in another article [can't remember which periodical], I heard as high as 30%. Anyone know of a reliable source for this information, or does one even exist?

      As to the argument that US Middle East policy is to assist its allies' oil interests moreso than its own, some analysts would argue it's not that simple. They theorize that since oil is a commodity that has its price set by the world market, any significant disruption in oil production is bad. Even if the US could absorb the loss of 10% oil production, the impact of that reduction in Middle East output could force the world's other consumers, dependent on Middle East oil, to hit suppliers used by the US, increasing demand and driving up prices. So as the argument goes, the US is acting in its own interests, not just as favor to its allies. This is without looking at the economic impact it might have on those nations, and therefor world trade.

      However, by way of reference, as of 1999 10% is about 2 million barrels a day for the U.S., 60% is over 3 million barrels a day for Japan, and 35% is over 5 million barrels a day for Western Europe. This is based on statistics at http://www.eia.doe.gov/pub/international/ieapdf/t0 1_02.pdf

      Does this all mean that the airline industry wanted to use fuel cells for years or that the oil industry lobbied the FAA against it? In my opinion and experience that statement would be a little far fetched, however if you disagree, I'd love to see some data/reports showing otherwise, as I'm always curious about the data behind the conspiracy. . .

  44. Reality Check by Anonymous Coward · · Score: 0

    I have noticed that many of you would like to see a pure H2 system. It will not happen for quite some time. The actual change to an electrical set-up is expensive. New Fuel distro (be it at airports or automobile stations), all new Mechanics, and new manufactuering. It is almost certain that the first round of fuel cell technolocies will have to work with our current systems. That means for homes it will be natural gas and perhaps propane. For Automobiles, it will have to be gasoline. Finally for the APU of a commercial aircraft, it would be best if it worked with jef fuel/kerosine. Not likely, but using gasoline would be possible.

    For those of you who think that this will kill the oil company you are kidding youselves. By trying to use a disruptive technology in a system which is built on another, it will not be easily changed. HDTV is much better, yet goes slowly. Linux kills M$ on all fronts of the server yet is is just really starting to me accepted. For this to be really accepted it will have to use current delivery systems and then over time, be switched.

  45. To be pedantic... by sysadmn · · Score: 1

    Actually, jet fuel can explode, but it's damned hard to do it. You've got to vaporize the fuel and mix it thoroughly, then ignite it. Gaseous H2 is way more explosive.

    --
    Envy my 5 digit Slashdot User ID!
  46. Quite right by rebelcool · · Score: 2
    Considering there is no hydrogen infrastructure anywhere, it will be a long time before the world converts to such things.

    For h2 in cars to work, you need hydrogen stations. Converting gasoline into hydrogen for a few years while gas stations add hydrogen pumps is the way to go.

    And the oil companies are crafty. Indeed, there is no such thing as an 'oil' company today. They refer to themselves as 'energy' companies for a reason - they deal with more than oil. You can bet you'll be getting your hydrogen from texaco and chevron's offspring in 25 years.

    --

    -

  47. Wrong. Jet Fuel far, far worse than hydrogen. by rebelcool · · Score: 2

    were the planes powered by hydrogen, the buildings would still be there. Jet fuel burns nastily and is extremely flammable. It puts hydrogen to shame. The whole reason that they dont use hydrogen in cars and planes to date is because it contains much less energy per pound (which means you need HUGE amounts of it)

    --

    -

    1. Re:Wrong. Jet Fuel far, far worse than hydrogen. by Anonymous Coward · · Score: 0

      so you are saying we should replace the hydrogen in fusion bombs with jet fuel and step back?

  48. Screw fuel cells. Use fission instead. by trenton · · Score: 2
    I don't know why people are going on and on about fuel cells. They're great for space vehicles, where weight is the #1 concern. But for aircraft, why not use nuclear power. Nice and clean. No emissions. And it's a technology that's been used for 50 years.

    Here's a great picture of a prototype. Note the concept plane at the bottom. The flight deck "could be detached in cases of emergency." What more safety could anyone ask for?

    --
    Too big to fail? Does that make me to small to succeed?
    1. Re:Screw fuel cells. Use fission instead. by The+Cookie+Monster · · Score: 1

      Nuclear isn't a renewable energy source, and I assume your trolling when you say nice and clean - "venting the exhaust" into underground dumps instead of the atmosphere doesn't mean it's clean.

      Fuel cells are also extremely efficient, nuclear reactors are very inefficient.

      Geeks love fuel cells because you just don't get more elegant, fission reactors are such an ugly hack.

    2. Re:Screw fuel cells. Use fission instead. by Pravada · · Score: 1

      The army actually worked on this in the fifties (the glorious nuclear age). There were a couple of problems. One was that containment is VERY heavy, especially when you're talking about a something hurtling along at five hundred miles an hour. The second was that there's only so far a pilot can fly. nuclear power in a plane was overkill by several orders of magnitude.

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      --- On the other hand, you have five fingers.
  49. WTC impact by loosenut · · Score: 2

    Another advantage, which no one seems to have mentioned, is that fuel cells make aircraft far less *explosive*. Without gasoline, they are no longer flying bombs. Aircraft security issues are returned to pre-9/11 status.

    1. Re:WTC impact by The+Cookie+Monster · · Score: 1

      Fuel cells are most efficient when running on straight hydrogen, which may have it's own safety issues.

    2. Re:WTC impact by rew · · Score: 1

      Another advantage, which no one seems to have mentioned, is that fuel cells make aircraft far less *explosive*.

      Bullshit. They need to carry the same amount of energy stored in "chemicals", as planes previously did.

      However, they might fly on "methane" instead of airplane fuel, as that works better in fuel cells.... Catch my drift?

      Roger.

    3. Re:WTC impact by loosenut · · Score: 1

      The potential energy is the same, but the way the fuel behaves when it crashes into a building is different for each chemical.

      By your argument, I could be an olympic athlete in training, and the day before the big event, I could either eat a 2000 calorie salad for dinner, or I could eat 2000 calories of Snicker's bars. The amount of chemical energy is the same, right?

      I heard some guy from the Phoenix Project on NPR the other day, and he was talking about how the jet fuel in the WTC attack was really heavy and dense, and just stuck to everything. On the other hand, hydrogen is light, and if it were being used as fuel in the attacks, it would have pretty much just floated away. Of course, some damage would have been done, but not anywhere near as much.

    4. Re:WTC impact by rew · · Score: 1

      By your argument, I could be an olympic athlete in training, and the day before the big event, I could either eat a 2000 calorie salad for dinner, or I could eat 2000 calories of Snicker's bars.

      If you run a marathon, eating 2000 calories of snickers is a good thing, about half an hour before the start of the run: Snickers have a mix of glucose (active 15-30 minutes after ingestion), sacharose (active 20-60 minutes after ingestion) and starch (active 45 to 120 minutes after ingestion). And then there are fats which you end up burning a few of near the end of a marathon too. I'm not sure wether fats are "ready for burning" if you didn't eat them weeks before. So the calories contained in the fat in the snickers may be wasted on the marathon runner.

      Salad is "good" because it contains fibers and stuff. The day before the "big event" that's no longer going to help you. 2000 calories of Salad is "bad" because a pure vegetable salad is almost calorie free. Thus you'd have to overeat A LOT before you get 2000 calories.

      If a hydrogen-burning airplane would've hit the WTC, there would have been a much more fierce explosion at impact. And a Humoungous fireball for the one or two minutes after that. And no more WTC after 3 minutes. (You get an explosion limited by the amount of oxygen that can be provided...)

      I think that the impact blast would've been powerful enough to collapse the buildings like now happened after 50-80 minutes.

      If the fuel cells would run on say methane, similar things happen. Methane burns cooler. Less violent explosions. But still orders of magnitude more violent than airplane fuel.

      If you have a wooden bar, and hit it with a hammer, trying to break it, there is a certain amount of energy required before it will break. If you slowly push it using a jack, you will find that you need almost the same amount of energy to break it.

      Breaking the WTC took a certain amount of energy. The airplanes contained that amount of energy, not in their kinetic energy, but combined with their fuel-supply they HAVE the required energy to "break" the WTC in two. Complete destruction was then due to the energy contained in "20 stories of WTC falling down".

      An airplane fuelled up for a 10 hour flight simply has enough energy to bring down the WTC.

      Roger.

  50. Enegizer bunny by Anonymous Coward · · Score: 0

    Without reading the article...

    you better hope that rabbit is *still* going...

  51. Re:hydrogen must be stored at large pressure by Anonymous Coward · · Score: 0

    Actually the hydrogen doesn't necessarily need to be stored at an extremely high pressure. I read an article somewhere that told that fuel cell researchers have actually been able to store more hydrogen by imbedding it into a metal such as magnesium or graphite rather than at high pressures in a liquid form. I believe it was something like 30 litres of hydrogen could be stored in a single gram of graphite. I'll post the url if I can find the article again.

  52. Since when do airliners use fusion? by rebelcool · · Score: 2
    That is entirely irrelevant.

    Now if you were able to fuse the various atoms that make up jet fuel (is such a thing possible? Not even stars fuse much more than hydrogen..) then yes, I would step back.

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    1. Re:Since when do airliners use fusion? by Anonymous Coward · · Score: 0

      Not to just pick on you, but I would like to see some scientific facts before blanket statements such as The whole reason that they dont use hydrogen in cars and planes to date is because it contains much less energy per pound.
      As far as oxidation goes, it would be impossible to get any element or compound to weigh less than hydrogen and oxidize it. How much energy is released from oxidizing one molecule of hydrogen? How much energy is released from oxidizing one molecule of jet fuel? The state of the matter and handling characteristics would be more important in airplanes and cars as most people don't want to handle liquid hydrogen.

  53. Metal Hydride storage by sandgroper · · Score: 1
    The H is stored as interstitials in the crystal lattice of the metal. The rate of leakage is determined by the diffusivity of the H through the interstitial "lattice", which means that it is thermally controlled. H discharging from a metal hydride cools the metal (so much so, that it might be useful as a source of "coolth" co-generation). Implication: the discharge rate slows down when leaks happen. Oh, and the energy density can be much higher that that of liquid H.


    Any Questions? (This will be on the test.)

  54. "SECOND" to something _being worked on_??! -NT by Anonymous Coward · · Score: 0

    NT

  55. Nuclear reactors under the hood? by Anonymous Coward · · Score: 0

    Sure, if you can survive the irradiation you'll get. Without adequate shielding, it'll be the first and last atomic car you'll drive.

    Realistically, we'd use stationary atomic reactors to make hydrogen, and you'd "burn" the hydrogen in your car.

    Gasoline is a fossil fuel, and there are finite quantities of it. Once it's gone, it'll be another 200 million years before nature gets around to recycling it back into fossil fuels.

  56. the real danger... by Anonymous Coward · · Score: 0

    It's a known fact that we're going to run out of fossil fuels in the near future ... what happens when planes start running out of gas and falling from the sky?

  57. compressed air by mr.ska · · Score: 2
    You show me an electric motor over 50hp that doesn't require a crane to pick up. Being essentially complex hunks of steel and copper, electric motors are HEAVY.

    Having said that, yes, a compressed air motor would be more powerful. But how do you propose to compress that air? Store it on-board? Great - if you're lucky you'll have enough to taxi down the runway before you run out. Compressed air as an energy storage medium is HORRID.

    If you think you'll just compress it on-board, how are you going to do that? You'll need a 225HP compressor motor (allowing for losses)!! So you're better off going for pure electric right off the bat.

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    Mr. Ska