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Hydrogen Powered Cars 219

ErrantKbd writes: "CNN's science section features this article about BMW's recent tinkerings with hydrogen-powered cars. It has some interesting information about safety issues, which are understandably a major concern for cars no less than for zeppelins. Hopefully other manufacturers will adopt the same attitude as BMW, so the rest of us can afford these if they should ever emerge on the market." For now these cars have a limited range and one (1) fueling spot, which is fine if you commute to and from the Munich airport. One day, though, it'd be great for the rooftop solar collector to be separating fuel for the next day's commute ...

Hydrogen Powered Cars

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  • by Anonymous Coward
    It's not a myth. Observe what happened to hemp in 1937 when something invented a process to make better and cheaper paper than that from trees.

    The Original Threat to the Petro-Chemical Industry []
  • by Anonymous Coward
    March 17, 2005

    It seems that the long touted "clean fuel" of the 21 Century had some unfortunate and unexpected consequences today when the massive amounts of H2O converted to car fuel finally caused the ocean to sink (The process of the surface of the ocean passing below the rising continents) due to the demand for hydrogen created by urban commuters.

    "We were really caught off-guard on this one," says John Shepley, an engineer at the BMW Deep Valley Station, one of the three man made structures still with a beach front. "Everyone knows that the coasts have been crawling farther and farther for years. The granola eater types really started complaining when California lost its coast, but we figured all that liberal spouting was just hyperbole. I guess we were wrong."

    The engineers have been working for some time on further innovations that may make the world inhabitable once again. "Yeah. We can make a machine that uses combustion to turn H2 and O2 molecules back into water, but the only design we could come up with didn't use fossil fuels. We figured, no, we'll stay away from that. Not using fossil fuels would be a blow to our economy."

  • by Anonymous Coward

    How does a solar collector work for the "next day's commute"? Would that be a solar collector that takes in starlight, moonlight, or city lights reflected by clouds? Have you any idea how much energy it takes to separate hydrogen out of water?

  • I hope for alternative fuel sources, whatever they may be; however, for the future the real answer IMO would be new forms of "public" transportation. Cars have always symbolized a freedom. You can go when-ever/where-ever you please.

    As the lands become tightly packed making the world appear as one giant city, there will be a network of tubes. With shuttles travelling at incredible speeds taking you where you tell them to. Private transportation will be no more than an upper-class luxury rather than a mode of transportation.

    Ok, to that's a little too far into the future.

    As long as we're able to enjoy the pleasure of being in full control of our modes of transportation, it would certainly be nice to enjoy clean air at the same time.

    Sorry if this is somewhat off topic.
  • From:

    Zeppelins are still what people most associate with hydrogen, and the Hindenburg disaster is probably the most well-known event involving hydrogen. The Hindenburg's association to hydrogen has created a negative public image of the gas, and has perpetuated the myth that hydrogen is extremely dangerous. The Hindenburg was actually designed to use helium as the bouyant. At the time of the ill-fated journey to New Jersey, helium was extremely hard to come by due to U.S. trade embargoes. They used hydrogen, the next best thing, but the ship was not equipped with the necessary safety features required to deal with the flammable gas. The explosion was well covered by the media at the time. Little known is the fact that most of the deaths (there were thirty six casualties) were not attributed to the actual explosion, but occured when many tried to jump to safety and died on landing. It is now established that hydrogen is, in fact, less dangerous than most fuels used today.
  • (Yes, I'm replying to myself!)

    A better link is available here []

  • Price has nothing to do with it, the context [] was the allegation that hydrogen cars aren't clean because of the electricy involved in creating hydrogen.

    Please read the whole thread before responding to the middle of it.
  • Electricity is needed to extract oil too, y'know. And as many have already pointed out, hydrogen is no more dangerous in cars than gasoline. In fact, it could be argued that it's less dangerous.

    It's a "clean energy" because the car itself isn't polluting much. Of course, this argument has the same flaw that electric-powered cars do, which you pointed out. No matter how egological the car itself is, the power it uses has to come from somewhere, and in most of the US, that means coal-burning plants.

    And from what I understand of the CA situation, coal plants are the only new source of power being seriously considered down there, because they're simple and cheap to build. Sigh. As if we didn't have enough rampant pollution already.

    Me, I want a fuel cell car. I won't drive an electric car, though, since so much of the electricity to charge it gets lost in transit over the power lines.
  • I'm confused. You spent all that time explaining why hydrogen isn't really efficient, it just moves the pollution.

    And the you say to use electric cars? Can you please go back and read your argument again, and tell me why electric cars are any better of a solution?
  • It's always nice to be jumped on for being in the US. I do appreciate your uninformed assumption, even if it is true. Please, continue to believe all Americans are completely unaware of the world beyond their borders. It really is a healty attitude.

    As a side note, I'll mention the area I live on is powered exclusively by hydro power. Yes, we're fortunate to be able to do that, since much of the country is too entrenched in fossil fuels to adopt other means.

    The problem with cleaner sources of power is that they just don't meet the demand. Solar is fine, but it swallows up massive quantities of land (Yes, I realize the irony in an American griping about using up land). Same with wind power. Hydro is a good option for areas that can employ it, and it's my favored source of energy. But what else is there? Well, there's global warming. At some point that reality is going to kick the US government in the ass and get them to actually act, and push industry to find better ways to generate power. In the mean time, politics prevents any progress from being made over here.
  • Actualy, most people being stupid, don't think to consider several factors that lead to the myth of hydrogen being dangerous.

    #1: people survived the crash of the hindenburg. when was the last time someone survived a crashed 747?

    why? because hydrogen is lighter than air, and moves upward while it burns. jet's use a liquid fuel, which sticks to everything, and causes much more damage. it goes the same for cars, gasoline is just as volitile as hydrogen, actualy it's more volitile, because it has a higher energy density than hydrogen. it takes a supercharged diesel to produce similar engine preformance to a gasoline engine of the same displacement with hydrogen. Hydrogen is not an optimal fuel when it comes to energy density.

    an auto accident with a hydrogen vehicle would be similar to an accident with an LP gas based vehilce. unless the tank is punctured, there isn't much of a problem.

    the thing that makes hydrogen a slightly more dangerous fuel is the fact that it must be stored presurized at cold temps to get any kind of sufficent quantity of the stuff stored in the same space as gasoline.

    this is why I'm still an EV fan. batteries somewhat safer than combusting fuels. they only have the major drawback that current batteries have really nasty chemicals inside, lead, hydrochloric acid, lithium, Nickle. I can't wait for polymer batteries. :)
  • Posted by mcarp:

    Ok, I pretty much read most of these replies and it was pretty tuff to decide where to stick a comment. I've spent a great many man hours reading about alternative fuel and I have to say that most of what is addressed here is not new. Solar takes a long time to make very much useful electricty, uses up too many raw materials to manufacture collectors and the payback is long term with the collecting systems being expensive and large. Electricity can indeed by produced in what is now a well thought out and large scale industry but increased demand would be hugely more than we can muster and what about the batteries? Think about the waste byproducts from batteries, spent acid, lots of used up zink. Where are we going to put all those spent battery components? Will it cost too much to recycle such large quantities of batteries? Aren't vehicle batteries already a big mess? Multiply that by at least 10. Hydrogen from natural gas? Please, just burn the the gas as is. And i have tons of other discrepencies with the other alt sources mentioned. But here is the #1 question I ask all of you since no one has seemed to think about it. Where is all that water going to come from? Fresh water is cheep yes, but will it be cheep after its demand is doubled or worse? Some areas already have rain deficits, low water reserves and its still cheep water but how long will it be if we burn it all? The exhaust water vapour will be more than the exaust liquid so most of it will be evaproated away...ok so are we counting on it to rain more after we start using water as a fuel? Is that enough? Ok so what about using sea water? Pipe it in? Locate refineries and H2 plants on shores? Maybe... but at what expense? If we pipe it how much does that cost? Fresh water we cant afford to burn, sea water we cant afford to pipe or even refine. No sir. Hydrogen fuel is a long LONG way from being a useful alt fuel.
  • Posted by damiam:

    I think what some people here are missing is that hydrogen has energy in and of itself. When you burn hydrogen, you don't just get back the energy it took to electrolyze it, you get back the chemical energy in the hydrogen itself, which is usually much greater.
  • Posted by duke of W:

    Lets see now .Solar collectors on car make hydrogen then hydrogen is fuel, that runs car. At night these solar cells can catch up on the inefficiencies of this system. I gotta goe, the white jackets want me back....
  • Solar is fine, but it swallows up massive quantities of land

    This is a misleading statement. Solar "fields" take up more space than an equivalent coal-fired and/or oil-fired station but the argument doesn't take into account the land occupied by mines or rigs, tailing dams, fuel refineries, shipping ports, waste storage, etc. The argument also neglects to account for the land occupied by supporting industries.

    Also fossil fuel plants cast pollutants into the air and waste heat into the rivers and lakes, so their actual "space usage" is actually much higher than land occupation.

    You can also put solar cell/trough/mirrors on top of house-roofing: something you can't easily do with conventional fossil fuel plants. The roof space is typically unused and is a perfect point for collecting solar energy. So land requirement are even lower for solar energy than you might imagine.


    Exactly. Many countries have vast tracts of unused, unusable land. Australia and the USA are perfect candidates for wholesale conversion to solar power, if they can ever get the costs down.


    The Australian Snowy Mountain Hydro-Electric Scheme is an extensive hydro power source but sadly it may have been a minor disaster. The damming of the rivers has caused significant ecological and environmental damage downstream. They will be cutting back energy production in the near future to let the land recover. It has soured my opinion of hydro: the damage to the environment is still there albeit a different (less obvious) form.

  • If you are assuming that you are going to take compressed hydrogen gas and burn it to make H20, then you have a real problem. The energy to split H20 to make Hydrogen gas is greater than the energy you get out when you later burn the gas. Its that pesky second law of thermodynamics again.

    Ofcourse the energy required to create oil is greater than what we get out of it too. Its just that that energy was put in by biological proccess when the oil was created. (Could be petrol or olive oil)
  • Die antwort ist.... füllen Sie sie herauf
  • As several people have already mentioned, use solar power. Electrolysis doesn't take much energy, so you could use solar power to seperate large vats of dihydrogen monoxide.
    Hell, get your ass on a converted exercise bike and earn the gas you'll be using the next day. Kill two birds with one stone.
  • For now these cars have a limited range and one (1) fueling spot,

    I couldn't find the man page for one(1). This doesn't seem to exist:
    $ man 1 one
    No entry for one in section 1 of the manual

    In fact, there isn't an entry for 'one' in any section:
    $ man one
    No manual entry for one

    Perhaps you meant zero(4)? (Sorry, couldn't resist.) :)

  • I love how BP, Texaco, Mobil, et. al. are evil because they produce gasoline.

    I mean, wow -- Texaco is evil? What's Texaco? Well, it's your grandmother, for one. Your parents, possibly you, your sainted aunt and thousands of widows and orphans who depend on Texaco's profits in order to eat

    Point one: Texaco is a corporation. Anthropomorphizing Texaco by calling it evil is just plain silly.

    Point two: Texaco deals in petrochemical by-products, only one of which is gasoline. To say that Texaco will suppress a hydrogen powered car because they won't be able to sell gasoline is asinine. It's the same as saying that your local drug store will suppress the planting of willow trees because it will impact their sales of aspirin. (willow bark contains aspirin-like chemicals and can be chewed to release the chemicals)

    Texaco will continue to provide oil to people who make Vasaline, lipstick, WD-40... so they stop selling gas? Big deal -- they're still needed for home heating oil, kerosene, Castrol, you name it.

  • You are assuming hydrogen combustion. The much more interesting work in that regard is on hydrogen fuel cells, which produce electricity from hydrogen and oxygen from the air via catalytic reaction. From what I've read, they are extremely clean, nearly distilled-grade water as the exhaust. "mmm thirsty, need to drive somewhere..." 8-)

  • You are a bit pessemistic with those values. Most NA (Naturally Aspirated) engines have a BSFC (Brake Specific Fuel Conspumption) of .5, turbo and super, .6. What this means is that they are only 50% efficient, and 40%, respectively. Then there is VE (Volumetric Efficiency), which is the relative performance efficiency of an engine with respect to it's displacement.

    But the rule of thumb is that it generally takes the same amount of fuel to produce the same amount of horsepower. This rule is only upset when you have ultra efficient engines with a BSFC of < .4 or VE of .8 or greater.

    I can tell you right now that the 750hl motor is the least efficient motor to use. It has an average of 12MPG with only 300hp produced, so it's BSFC and VE numbers are way off. However if you look at it's CR (Compression Ratio), you'll understand; it's 8.5:1, very low by today's standards. However this enables you to run low octane fuel in it, or add a power-adder (Nitrous, Super and Turbo charging) without making any mechanical changes to the motor. BMW probably thought that a street driven 500hp motor in their luxury car was pushing it a bit, because that's what you'd get if you ran 10:1 CR. That's what many cars today use, some higher when small displacement, and some lower when large displacement.

    Great sig. In the good old days, this sig would cause many fights. It seems that some stupid terminal programs would see this in people's sigs and proceed to reset the modem for a redial. It was a pretty good prank.
  • What would you rather have? A tank of hydrogen in a 1/2 inch thick steel bottle, or a tank of gasoline (with just as much energy) in a tank made of *plastic*?

    I'll take the hydrogen.
  • The rusted metal gas tank is also mighty thin. Especially in Pintos.
  • Potatoes then. You can ferment anything with sugar in it to get alcohol. You could probably ferment a possum if you ran out of juice miles from an alcohol station.

  • by PD (9577) <> on Saturday March 17, 2001 @08:33PM (#356704) Homepage Journal
    Toilet cleaner (with HCl) and aluminum foil work well too.

    I'd like to see alcohol become a widely used fuel. The corn gets carbons from the air, so when it is burned, the carbons go back to the air. It would solve a big problem with CO2.

  • Actually, what the Zeppelin company used was a combination of aluminum powder and nitrocellulose as a doping compound for the canvas covering of the Hindenburg, which was supposed to reflect heat.

    Unfortunately, the Zeppelin people didn't know the doping compound was extremely explosive. It was research by a NASA scientist who managed to get a sample of the outer skin covering from the Hindenburg and looked at its chemical composition that he noted it had almost exactly the same properties as the solid rocket fuel used on the Space Shuttle SRB's. He came to the conclusion the ignition of one of the canvas covers possibly set off the hydrogen gas.

    In fact, a secret Zeppelin internal report done in 1938 also noted the penchant of the doping compound to burn extremely rapidly, but that report was squelched by the Nazi authorities for propaganda reasons.
  • No, batteries just have issues with

    A. Amount of energy vs weight (yes, that energy can be replenished over and over, but one charging of 1 kilo [or choose your preferred measure of mass] of battery is less than 1 kilo of any reasonable fuel) You also have to carry dead weight around as the battery is drained -- 'dead' fuel is burned and is not carried by your vehical.
    B. Recharging -- granted, part of this is a social problem and can be dealt with (by having recharging stations) but even your corner recharging station isn't going to help the fact that it takes far longer to recharge a battery than to fill a fuel tank. And if you happen to be going somewhere without stations of the appropriate type, it's more efficient to carry containers of fuel than fuel + generator.
    C. Hydrogen (in particular) is far less polluting than Lead Acid batteries -- in generation and in getting rid of it at the end of it's useful life. (Yes, recycling is good. however, I'm not seeing americans recycle -- in fact, I'm beginning to see backlash -- recycling is *not* cool -- I don't believe that, but my belief doesn't change the fact that many do believe that)

    And leaking gasoline isn't half so dangerous as an exploding gas tank on your standard sized car. Think of the blaze if the hindenburg had been filled with gasoline (that's a lot of volume there).

    Oh, and the original poster was at least sort of []

    Specifically, the bit about the fire not being consitant with a hydrogen fire/explosion.

  • The solution to the fueling infrastructure problem is obvious. Not simple, but obvious.

    Let the consumer buy their own filling device.

    Like timothy said, someday they oughta be built into the car, with solar panels on the roof providing the energy to seperate the water by products back into hydrogen....

    But in the meanwhile, they oughta be able to come up with something the size of a wardrobe or two that you can stick in your garage and use....

    (powered, of course, by the solar panels on your roof and windmills in your yard)

  • So if a drunk driver's breaks fail, then it's okay to drive drunk, because driving drunk didn't cause the accident?

    Hydrogen is still dangerous, Hindenberg anecdote or not. If Challenger wasn't sitting on a tank of liquid Hydrogen and another tank of liquid Oxygen, the challenger disaster would have looked very different, and might not have even happened, despite the fact that Hydrogen wasn't responsible for the failed o-ring.

    Hydrogen isn't safe. Not that gasolene is particularly safe, but the logic in the parent post is pretty contrived and false.

    Kevin Fox
  • You're right. It is all about comparative risks, and I wasn't making the point that Hydrogen is a a bad fuel, just that it's not a SAFE fuel. In response to your assertion that you have to have a fuel, and therefore an unsafe fuel, for locomotion, be it spacecraft or car, I'd point out that lead-acid bateries don't tend to be as explosive as gasolene or hydrogen.

    Also, in response to those who point out that leaking hydrogen floats upwards out of harms way, this is a good poiont. Leaking hydrogen isn't half so dangerous as an explosive release of pressuraized gas (flammable or not) that a hydrogen-powered car carries around.

    Kevin Fox
  • Here's [] a nice article posted more than a year ago on slashdot about producing Hydrogen in Algae filled ponds. Sadly the link is broken, but search on most search engines and you'll find what you need to know. Apparently the aparatus is fairly simple. It might even become a backyard industry. Imagine growing and cultivating your own fuel for your car. Being a commuter, I know if I could supply my own fuel I'd have probably another $100 a month to use. Over 3 or four years the savings would more than be paid back.

    Who knows, pipe dream or whatever, it's a nice one.
  • As optimistic as I am about alternative-powered cars, I always fear that the multi-billionaire oil companies will just step in and squash whatever idea people have about alternative fuel.

    Maybe it's just a myth, but if I were some huge rich cigar-smoking king-of-cash, I'd want to trample whatever threatened my empire. Kinda like Microsoft :)

  • If you're going to base your argument on energy density, you might note that all current and prospective battery technologies are absolutely horrible by comparison to any combustible fuel. Battery power per unit mass is several orders of magnitude lower than, say, gasoline.
  • Humidity isn't helping you, but cooler, denser air is. The main advantage of ram air systems like on your Camaro is not the increased pressure of the air cramming into the intake at 70mph, but the fact that that air is from the cool outside, rather than from the hot engine bay. I'm not familiar with the particulars of the Camaro's system, but I know that cold air induction kits for Miatas are good for about 5-10% increase in horsepower.
  • OPEC is the Organization of Petroleum Exporting Countries, consisting primarily of Persian Gulf area countries who produce the vast majority of cheap oil on Earth. There's plenty of oil outside the Persian Gulf's just very difficult and expensive to locate and extract it. So, since getting oil around the PG is pretty simple and inexpensive, those nations have a very strong bargaining perspective WRT the oil companies who want access to their fields.
  • Also, ``no one was directly killed by the hydrogen fire in the 1937 Hindenburg disaster. Some died in a diesel-oil fire or by jumping out of the airship, but all sixty-two passengers who rode the flaming dirigible back to earth, as the clear hydrogen flames swirled upward above them, escaped unharmed.'' (Natural Capitilism, p. 35)

    Note that, as this quote mentions, hydrogen flames are basicly transparent. The big fireballs in the Hindnburg footage were not burining hydrogen. Also, hydrogen needs a ritcher mixture than gasoline, and it disipates up rater than sticking to things like gasoline.


  • Hydrogen power is great for cars. I'm all in favor of it. Assuming that all the engineering aspects are worked out, and the oil companies don't block anything (which is assuming a lot) there is still a problem-supply of hydrogen. You can't just go and pick it up off the street. Electrolysis of water is expensive and time-consuming. One of the solutions to this problem was using natural gas plants to produce hydrogen during the non-peak hours. This was a great idea until natural gas prices skyrocketed. So this probably won't be a viable method. However, some of you may remember a story on slashdot a year ago about how algae can produce hydrogen. I'm placing a lot of hope in this. Maybe, in the not too distant future, people can have little algae ponds outside their houses that will produce hydrogen to fuel their cars. Other than these three methods-algae, power plants, and electrolysis, I don't know of any other ways to really make hydrogen for fuel cells. And none of them is that practical right now. Just something to consider in the hydrogen fuel cell debate.

    Colin Winters
  • Has anyone here really stopped and considered that millions of people driving personal trasportation devices is just going to be bad for the environment regardless of how they are powered? Sure, switching to a cleaner energy source will clear up alot of the pollution from emmisions, but what about the 'other' emmisions?

    For instance, how often do you replace the tires on your vehicle? Once aevery year or so... and where do you think all that tread is going?

    Wiper fluid... lubricants... turtlewax... it all adds up, you know? Maybe we should focus on ways to scrub our environment instead of just limiting what millions of people release into the world every day.
  • Given the choice between petrol and hydrogen on grounds of safety, Hydrogen has one very significant advantage.

    It's really, really light. If it leaks out of its controlled environment it goes straight up, extremely quickly. As opposed to the petrol, sitting in pools underneath the leak.

    Really, it's nowhere near as bad as its reputation. Quite good, in fact.
  • Takes too much land to produce enough fuel to run enough vehicles.

    It's a lovely idea but is only workable on a large scale when there's a really, really big surplus of agricultural land.

    There was one interesting idea which I heard about a while back, though - mutant algae producing hydeogen. Wonder what's happening on that one?
  • Stationary pollution is easier to deal with. Plus, nuclear plants don't contribute to global warming, don't emit ordinary pollutants, and are cheaper than any other technology when all costs are accounted for. And yes, the risk of a nuclear power plant has been socialized. Then again, so has the pollution from a coal plant, or the pollution from producing solar panels.

    But rather than argue about it, we should just make sure that each technology has to pay the full cost of its operation. Then we let the free market choose.
  • The Hindenburg dident blow up because itw as full of hydrogen, it blew up because it was coated in the same stuff the Solid rocket boosters on the Space shuttle use for fuel, or at least something verry similar

    It also carried a large amount of Diesel fuel...
    Had it been a hydrogen fire it would have not shown so many flames and been over in seconds
  • Gasoline has been deemed by society to be 'safe enough'. Hydrogen is about as safe/dangerous as gasoline. Therefore, hydrogen is also 'safe enough'.

    Except that since hydrogen is lighter than air it is less likely cause explosions in underground structures. Which is a big risk with fuels which are heavier than air (including methane.)
  • Yeah, that stuff they coated the hindenburg with was just ground aluminum.
    Look at your beer can. It is hard to believe that ground and processed right it would make a very nice bomb.

    Aluminium is actually about as reactive as sodium or magnesium. What makes it stable is that under most conditions in contact with oxygen (or water) it will form an inert oxide which prevents further reaction.
  • Several countries already blend their petrol with ethanol and it is not much of a step to make an engine that will be happy running on pure alcohol.

    Ethanol has a long history of being used as an "anti-knock" additive. Though TEL ended up being used for a long time, apparently more for political reasons than anything else.

    In fact I saw a bus at my local shopping centre yesterday that runs on pure ethanol.

    A fuel injected engine with load of electronic hung on should be less fussy about its fuel than a 100 year old design. At least in theory.
  • One of the major problems, is that the plant-based diesel fuels tend to come from seed oils. Most of the plant is not the seed, so you get relativly little return on the total biomass.

    Assuming the rest of the plant cannot form a commercially useful crop. Problem is one of the best candidate plants has been made illegal due to it's alkaloids. (Anyway plenty of plants are already grown commercially for only their fruit or seeds.)
  • Sodium hydroxide (NaOH) plus aluminium is the usual "recipe" for making hydrogen in chemistry textbooks: 2Al + 2NaOH + 6H2O -> 2Na(Al)(OH)4 + 3H2

    Remember that the aluminium was produced by electrolysis in the first place. Probably taking more electricity than the electrolysis of water...
  • Your idea, my implementation idea, hopefully will show prior art when someone tries to patent it.


    Imagine if the "tarp" was made with black colored Tyvek, and on the roll were two layers (like toilet paper), however, along the length of the roll the Tyvek is "bonded" (however they do this process - heat?) in a wavy back-and-forth across the length, so that a "tube" is formed. Cut at the right place, and you have an inlet and outlet for the water. Hook up the water system and go...

    Of course, all of this supposes one thing - Tyvek won't rot in the sun and weather. Not sure how well it would stand up in such conditions, pressurized with water. Perhaps another material could be used, like PVC or PEC?

    Worldcom [] - Generation Duh!
  • They used a pigmented dope on the fabric. The pigments used were iron oxide and aluminum.

    You may remember that pair of powders from your chemistry class. It's called "thermite".

    It's really hard to ignite. (You have to get the oxide layer off a particle of aluminum and melt the particle. Think of the oxide layer as saphire, or corrundum.) But a spark can do it if the pgiment is spread sufficiently thin or if the spark is hot enough.

    Once it's lit, it burns by the aluminum pulling the oxygen out of the iron oxide, leaving elemental iron and the difference in the heat of formation of iron and aluminum oxides. Iron oxide has a moderate heat of formation - you can burn steel wool if it's fine enough. But aluminum oxide has THE highest heat of formation of ANY compound. The difference is enough to leave the iron molten and glowing brilliant white.

    They weld railroad tracks by putting a thermite crucible above the join and letting the resulting molten iron pour down into a form wrapped around the rail. It melts the ends of the rail and fuses the whole thing into a single piece.

  • ... someday they oughta be built into the car, with solar panels on the roof providing the energy to seperate the water by products back into hydrogen

    You can forget the solar panels on the car. And Timothy can forget the ones on the roof, too. If you've got a few acres you might be able to swing it.

    The reason is the sheer AMOUNT of energy involved in mechanical motion. One horsepower is almost exactly 3/4 KILOwatt. Your car needs about 18 of them just to push the air out of the way as you cruise, more than a hundred to start up from a stopsign without inducing road rage in the people behind you.

    A 135 HP engine is putting out a tenth of a MEGAWATT. That's enough to power a thousand houses. The heat wasted in the brakes of a car stopping from 50 MPH, once, could heat a snowbound four-bedroom house for half an hour.

    Insolation is about one kilowatt per square yard. At the mid-latitudes of the USA you have about 5 solar hours per day. Let's be generous and say the panels are 10% efficient. And let's say your car has 3 square yards of panel area, you park it in unobstructed sunlight, and you have no weather. 4/3 * 3 * 5 * 1/10 = 2 horsepower-hours per day.

    But that's as electricity out of the panels, with perfect storage, perfect motors, and perfect regenerative braking. We were talking using it to make hydrogen and burning it in an engine. Divide by another factor of 5 (at least).

    Ok, now you're down to 2/5 horsepower hour. Call it one horsepower for twelve minutes. Call it enough to cruise for about a minute and a half at highway speed, or maybe enough to accellerate from a standing start to highway speed - ONCE.

    Not going to do much commuting that way.

    Of course that's why people are talking hydrogen rather than batteries and electric charge. Pumping gas into a car is equivalent to "charging" it at a rate in the BILLIONS of watts. You're not going to pull an electric into a station and give it a quick charge. You'd be using the entire output of a fossil fuel or nuclear plant to charge ONE car. The magnetic fields around the cable would bend the sheet metal.

    Ever wonder why electric cars are a BAD idea? Think about the power shortages in California. Then think about everybody commuting with electric cars. Figure a one-hour commute and perfect efficiency so you can approximate it as averaging maybe 24 horsepower. Figure charging them for 12 hours - 2 HP average. That's 1.5 times the power demand of the house, JUST to charge ONE very efficient car for ONE hour of commuting for ONE driver. For every two power plants we have now, build three more.

    Now add in shopping. Stop-and-go. Call it another four power plants. Drive from silicon valley to San Francisco and back for a little entertainment - five more. Don't even THINK of a pleasant drive in the country, or going to visit grandma for the holidays.
  • You're right when you say that this just moves the polution. The difference is that those big power generation plants are _much_ more efficient then your typical car engine. The typical oil power plant is ~40% efficient - compared to ~25% for a car engine.

    Those plants are heat engines. "Perfect" is closer to 35 if I recall correctly.

    But if you're using it to generate hydrogen, and burning the hydrogen in the car, the car engine is STILL going to get about 25%. So (using your numbers) you're getting 25% of 40%, rather than 25% of 100%, of the energy from the fuel.

    Oops! Now you're burning two and a half times as much fuel.

    Now if you could take the power the plant makes and store it 100% efficiently, transport it to the car without loss, and use it in the car without loss, THEN you'd have a 40% efficient car instead of a 25%. And you'd have moved the pollution and reduced it somewhat. That's what they're TRYING for with the electric cars.

    But forget about it. You make the car heavier with those batteries, so you need to move the batteries around, too. Net payload stays the same while gross vehicle mass goes up, and even with perfect motors, batteries, and transmission lines you end up with less efficiency.

    Better would be to use a car with regenerative braking and flywheel storage. LOTS to be gained there.

    But if you have regenerative braking and flywheel storage, you can use it in combination with a LITTLE internal combustion engine running at max-efficiency, and get rid of the major storage. Call it 200 horsepower-minutes of flywheel storage and a 25-horsepower engine running at closer to 30% efficiency than 25 and you'll get city mileage beating the country mileage of current vehicles, while country mileage also goes up, though not in proportion. You'll need a few other things to break 100 MPG, but it's no longer unattainable.
  • I live near many different railroad lines and have never seen this done (or a fused rail).

    Most railroads don't use welded rail. It's tough to do an expansion joint with no joints. B-)
  • I'm a little uneasy at flywheel storage. I've heard enough stories about what happens when early harddrives (heavy, quickly spinning cylinders) and ultracentrifuges "go" that I'm very apprehensious about them, especially when poorly maintained.

    And that's one of the big design issues.

    But it's not unique to flywheels. Imagine what happens when you get in an accident that shorts and/or spills the contents of batteries capable of delivering a megawatt for ten minutes.

    At least one uperflywheel design (which is NOT disk-shaped) is intended to go to powder if they fracture. And the breaking of the bonds absorbs a lot of the energy. (A superflywheel at max is operating where the molecules throughout its structure are strained just short of the breaking point, so the stored energy approximates the heat of formation of the compound.)

    But if it doesn't work it approximates a small bomb. (So you put it in a container that approximates armor.)

    Oops. Make that a tenth of a megawatt for ten minutes.
  • Sounds impressive, but is exaggerated. A 1000 kg car, running at 50 MPH has a kinetic energy of about 250kJ. Divide by 1800 seconds, and you'll get 140 Watts. This isn't going to heat a four-bedroom house. You'll need something closer to 25 kW for that.


    2112 units, 59 prefixes

    You have: megagram miles miles / hour hour
    You want: watt hours
    * 0.055512434
    / 18.013982
    You have:
    50 50 * 0.055512434 * p
    2 * p

    I get about 278 watts. Still a bit low, though.

    On the other hand, 25 kW is WAY too high. A space heater is about 1500 watts, so 25 kW is almost 17 of them. I don't know about you, but if I put 16 2/3 space heaters in a 4 bedroom house and jammed their thermostats so they ran at 100% duty cycle, by the end of a half hour I'd expect the house to be afire.

    Let's call it a well-insulated one-bedroom house and ten minutes. That's about one large space heater running about 50% duty cycle.
  • While I agree with most points you make, these numbers are not entirely realistic. A full tank of gasoline is about 2 MJ.

    I think 2 megajoules is a LOT low for a tank of gas - unless it's a lawnmower. The "units" command says a horsepower-hour is about 2.7 megajoules (2,684,519.5), which compares well with the approximation of 1 HP = 750 watts. A tank of gas yeilds easily over a hundred horsepower-hours. Multiply your two minute fillup at 15 megawatt by 100 and you've got 1.5 billion watts for two minutes.

    Multiply by another 4 if you're talking gasoline engines rather than electric cars with idealized 100% efficient batteries/motors and you're in the 6 gigawatt range for your 2-minute fillup gas pump hose. Which seams reasonable when you compare it to the fuel feed for a 1500 megawatt boiler.
  • Let's see...

    You're using energy from your electrical system to electrolyze water into hygrogen and oxygen. The electricity replaces, at a minimum, the "heat of formation" energy of the water as it cracks it to its elements.

    Then you inject the hydrogen into your intake manifold, where it burns with oxygen from the air, releasing the heat of formation - as heat.

    The heat is converted to mechanical power by the engine, which turns the generator to make the hydrogen.

    Perpetual motion? Hardly.

    A PERFECT heat engine only gets about a third of the energy out of the heat it uses. The other >2/3 goes to heat up a cold place. So you lose AT LEAST 2/3 of your energy each time through the cycle. And while automobile engines are pretty efficient they are optimized for portability, power-to-weight ratio, and a wide operating range. So they don't approach Carnot Cycle efficency all that closely. You need a big stationary power plant for that.

    Electric generators are good - you'll probably only lose another 10% there. More for the fan belts.

    Your electrolyzer won't be 100% efficient either. And that pump is pure loss.

    The hydrogen might do something useful to the mixture. But more likely it will just confuse the engine control computer, which expects to be working with a mixture of gasoline and air, and lower the efficiency of the engine further. (But probably not as far as if you tried it on a pre-computer engine, which doesn't have feedback from an exhaust oxygen sensor to let it adjust the gasoline flow to compensate for the hydrogen.)

    I suspect any mileage improvement to be an illusion. But there's one possibility for some improvement from this setup. The bubbler is probably putting some fine water droplets into the intake manifold. Water injection does help an otto-cycle engine, making a non-trivial improvement in both mileage and NOx emissions. The droplets boil and the steam helps transfer the energy into mechanical effort against the piston, while the boiling water cools the burn and reduces combustion of nitrogen.

    It's not done in cars because it's an expensive extra complexity, leaves you with TWO consumable liquids to run out of, and tends to rot the metal. Compared to a computer controlled engine without water injection it's not enough of an improvement in performance to justify the costs.
  • Actually I just caught a show on Discovery (Canadian) last weekend that covered alternative transportation, that included a section on Hydrogen as a method to power cars.

    Someone made an good point that everyone's eyes go wide when you mention H2 as a fuel, as they link it to exploding blimps.

    Yet, everytime we get into a car, we step into a small bomb. Gasoline is an extremely explosive fuel as well (of course it is, if it wasn't it would suck as a way to power a car.) and noone ever worries. Why? Well we have developed good saftey systems. How many people have actually seen a car explode in real life, as opposed to on the big screen? Not many I'll wager. Why, because gasoline isn't explosive? Of course not, because we have developed very good systems for keeping it where we want it, in the gas tank. The same will of course be true of hydrogen.

    So set aside the blowing up blips for a moment, since if your gas tank blows on impact you're probably not gonna hang around to worry about if it's hydrogen back there or petro, ethier one will burn you good and quick, and look at the other facts.

    1) Hydrogen produces relitively harmless byproducts when combined with air, mostly water (H2O), and would therefore resolve the vast majority of the air polution problems associated with vehicals.

    2) Hydrogen is relitively plentiful and easy to get at. Water is pretty available, and splits to 2(H), O through a pretty straight forward mechanism, and it seems concievable we could extract Hydrogen out of some of the hydrocarbons as well.

    As for the comments that the oil companies have been squashing alternative fuel vehicals, we're starting to see that change now. Many cities run on fuel cells (hydrogen batteries, essentially) and several mainstream auto manufactures have released hybrid cars that are dual petro/elect. I think the days of Opec's stranglehold on the world economy are likely numbered. Better educated consumers are questioning why we're stuck with a technology that has not changed signifigantly since its invention, when even in 8th grade, I could see that hydrogen was a superior solution for a fuel.

    Food for thought from an over caffinated mind!
    Remove the rocks to send email
  • Actually, producing hydrogen is very expensive, especially when using eletrolysis. The steam reforming method might be another story, though. But let's look at the cost of getting a megaJoule worth of hydrogen.

    Electrolysis is approximately 15% efficient, and you're going to pay about 0.04$ for a kWh of power. so .04/.15/3.6

    That means a megaJoule worth of hydrogen is going to cost you 0.075$.

    Now, gasoline costs 0.5$ per liter, and a liter of gasoline is good for about 31.5 megaJoules. That means gasoline costs 0.016$ per megaJoule.


    0.075$/MJ Hydrogen (electrolised)
    0.016$/MJ Gasoline

    Conclusion ? You're going to need to produce lots of power to make your oxygen. Power isn't free, or even cheap. Worse, you're using a 15% efficient process. It's going to cost you a lot of money to make your hydrogen on a commercial scale.

    Now, if you're using the latest hydrogen making processes, you might be able to achieve 80% efficiency. Over 5 times as efficient ! It drops the price of the power needed to make your megaJoule worth of hydrogen to less than 0.015$. That doesn't include all the equipement, personnel and taxes, methods of transportation and everything that you'll need to add to the cost of your hydrogen..
  • Differential tax regimes are tough to maintain. The reason that they color diesel/home heating oil is specifically to make it as easy as dipping a stick in your tank to spot a tax evader. But what realistic regime are you going to do for a gas fuel? Opening a pressurized tank of gas is certainly going to be more dangerous than a non-pressurized liquid tank. Is it possible? Sure, but it's a great FUD point for tax opponents.

    Another thing to think of, heating oil is much less common than natural gas heating and the people they check up on for violations are overwhelmingly commercial drivers. Natural gas cars are likely to be overwhelmingly passenger vehicles. A punitive tax regime that doesn't let any of the cost benefits get passed on to the consumer is simply not going to fly in this day and age. Differential taxation based purely on what appliance I put my gas into (heater, grill, or car) is a political non-starter.

  • by PhatKat (78180) on Saturday March 17, 2001 @06:42PM (#356767) Homepage
    March 17, 2005

    It seems that the long touted "clean fuel" of the 21 Century had some unfortunate and unexpected consequences today when the massive amounts of H2O released into the atmosphere finally caused the earth to sink (The process of continents passing below the rising surface of the ocean) due to the exhaust created by urban commuters.

    "We were really caught off-guard on this one," says John Shepley, an engineer at the BMW Space Station, one of the three man made structures still in existence. "Everyone knows that the coasts have been crawling closer and closer for years. The granola eater types really started complaining when California went under, but we figured all that liberal spouting was just hyperbole. I guess we were wrong."

    The engineers have been working for some time on further innovations that may make the world inhabitable once again. "Yeah. We can make a machine that uses electrolosis to turn water back into its component H2 and O2 molecules, but the only design we could come up with used fossil fuels. We figured, no, we'll stay away from that. The use of fossil fuels can get you into all sorts of trouble."
  • You forgot their biggest ally [].

  • There were a number of factors involved, not least of which being that the surface of the blimp was sealed with rocket fuel. It's a lot more likely to dissapate safely and cleanly than your average high octane (Which just sits there messing up the environment until it either sinks in and pollutes the water table or catches on fire.)
  • The efficiency is not as important as where the energy comes from. Currently much of the energy for transport comes from petroleum, much of which is imported into my country (Australia) and the US. With hydrogen engines the energy comes from electricity.

    Admittedly electricity is more generic, but considering the trouble the US is having with supply now it has to be asked whether the electricity system can supply the extra power for all transport. In addition to this, gas reserves are looking pretty thin, the US will probably be moving to coal-fired powerstations soon. If this happens the use of coal will skyrocket and it current prediction of 100 years worth will drop considerably.

    Hydrogen may help us transition to other forms of power, but what is really needed are new energy sources, not just ways of storing energy.

    I think sooner or later the human race is going to have to face up to the fact that we cannot grow forever. Short of usable fusion power our numbers and industry are already too great to sustain for more than a couple of decades. Getting smarter about energy is good, but as long as our society is modelled on exponential growth it can only postpone the inevitable collapse.

  • by jmv (93421)
    OK, hydrogen is supposed to be clean. However two things need to be taken into account:

    1) Normal cars produce three (at least) kinds of pollutions: carbon monoxide/dioxide, nitrogen oxides (NOx) and ozone (O3). Of course, hydrogen will not produce carbon oxides, but it will likely still produce nitrogen oxides and ozone. These are not created by the fuel burning, but by the effect of heat on the air (ie. the nitrogen in the NOx come from the air).

    2) How do you produce hydrogen? If you use electrolysis, then you need to get the energy from some place. If you burn fuel to get that energy, you're just moving the pollution. Note: while power plants are more efficient than a normal gas engine, the gain you have will likely be lost in the electrolysis.
  • by jmv (93421)
    If you read carfully my comment, I totally agree that power plants are more efficient than most (all) car engines. However, AFAIK, producing hydrogen using electrolysis is not that efficient, so the total loss may not be far from that of normal cars. Count the trouble of carrying hydrogen and I don't think the hydrogen solution is much better than the current gas-electric cars like the Honda Insight.
  • by jmv (93421)
    Well, since I started working for a speech recognition company (Locus Dialog []), I cannot (I'd be in a wierd position) work on a free speech recognition engine anymore. There are already (at least) two free speech recognition engines anyway (sphinx and isip).

    However, I'm still activly contributing to the Overflow project (a visual development environment), which started from the Open Mind Speech. (link in my new sig!)
  • by jmv (93421)
    Electrolysis doesn't take much energy

    Are you forgetting about conservation of energy? If you want enough hydrogen to produce 1 J, you'll need to put (1 J + losses) of energy into the electrolysis. So if your bike exercise produces enough hydrogen to power you car, you should consider just replacing your car engine by pedals...
  • Obviously since a "combustion engine" works by combustion and combusting something at the wrong time can be harmfull then any type of fuel used in one of these should be considered unsafe.

    Gasolene combusts more easily than hydrogen making it more likely to start combusting at the wrong time.

    So gasolene is not only dangerous as you said, it is more dangerous than hydrogen.

    Cyclists are more safe from stuff randomly combusting around them. But in my experience, people driving cars don't notice cyclists as much as they do trucks. And then you have the wacko's who like to try scare cyclists by driving their beat up pickup truck as close to the cyclist as they can and then honking the horn.

    Hope this helps.

  • My father works for BPAmoco, and he seems to believe that the company isn't really scared of these new technologies, or at least they won't be threatened for quite a while.

    Think about all the gas-powered cars there are out there. Think about how (relatively) inexpensive gas is, how readily available it is (there must be 5 gas stations within 5 miles of my house), and most importantly, how USED TO gas people are.

    Nothing is going to replace gas until it absolutely HAS to.

    -- Dr. Eldarion --
  • Iceland is currently underway of becoming the world's first hydrogen community. A fertilizer company has been making hydrogen since the 1950's and now the government has made a contract with Daimler-Benz that they make hydrogen powered busses for public transport. So other car manufacturers are working towards incorporating hydrogen powered engines. Also there's some talk of converting the fishing troller fleet to use hydrogen power. As oil is quite expensive here, cause of transport (we, pay the same for the liter here as americans pay for the gallon) And a oil distributor (believe it or not) has jumped on the bandwagon, and is going to provide these hydrogen powered vehicles with hydrogen in their gasstations, and are also selling small electric generators (12v, one amper) that use hydrogen. Everything is in fact in order.. Except for storage of hydrogen, which I hear is somewhat problematic.
    Iceland is the perfect place for this, as we have very clean ways of producing electricity in our hydroelectric powerplants. In relation to that, many government agencies have incorporated electric cars.

    Its a futuristic society :-)

    Anyway, I'm no authority in this field, I just repeat what I've read in newspapers/website. I have a couple of links but they're all in icelandic, but I do have one interresting picture: .G IF
  • Click Boom! is already taken, amiga software company ;)
  • You should look into postgresql! I mean, I realize this is a troll, but postgres is a much nicer database.

    Rate me on []
  • Ok, lets take this real slow and simple. When you burn something, you're combining with oxygen at a lower energy level. The energy you release is the difference between energy in the old chemical bonds and the new ones. Now these cars work by burning hydrogen, what do you get when you combine Hydrogen and Oxygen? That's right, water. Water is the byproduct of burning hydrogen (or, usually water vapor). In order to extract the hydrogen from the oxygen, you need to put energy back into the system... Burning the hydrogen would get you exactly as much energy as you put in to make it. Of course, you would loose tons of energy along the way (gas seeping out, mechanical ineffectiveness, etc). In other words, its not going to happen, and thinking that it could is ridicules.

    If you think you can somehow power a car by simply converting hydrogen and oxygen into water over and over again, well then, you are an idiot. Please stop telling people what they need to do.

    Rate me on []
  • There is a huge difference between using electricity to extract oil, and using it to extract hydrogen from water. In the first case, you're going to be using a lot less energy then you're going to be putting in, the energy is already there in the form of carbohydrates. You'll be able to get all the electricity you need to power the drill (or whatever) by using a tiny fraction of the oil you just got. On the other hand, there isn't any readily available chemical energy in water, the only thing you get out of it, is what you put in. It's more like charging a battery then anything else, and you're always going to loose some energy a long the way. You'll never be able to power a hydrogen creation plant off of the energy you get from burning the hydrogen you just got.

    Rate me on []
  • by Chester K (145560) on Saturday March 17, 2001 @06:32PM (#356804) Homepage
    I [] think [] you [] can [] figure [] out [] why [].
  • I agree to your points, but I still believe that liquid gasolene flying (and sticking) everywhere is more dangerous at the scene of an accident than hydrogen wafting up and away in the breeze.

  • by Ig0r (154739) on Saturday March 17, 2001 @06:31PM (#356810)
    Hydrogen burns quickly and more importantly goes UP as it burns, away from the veichle.
    Gasolene on the other hand burns slowly (in liquid form), flows everywhere, and sticks to everything it touches.

    Now which one, do you think, would produce more 'gruesome' accidents?

  • by Ig0r (154739) on Saturday March 17, 2001 @06:39PM (#356811)
    The amount of electricity required to electrolize water isn't that much, and isn't required all at once.
    You could have a giant field of solar panels slowly generating electricity and breaking tanks of water into O2 and H2 with little supervision needed.

  • Not to mention the fact that, if we convert to hydrogen fuel, SOMEONE has to produce it, move, and sell it....someone who has, say, gobs of money, huge tracts of industrialized land near the sea coasts for fuel, massive pipeline, trucking, and seaborne distribution networks for pressurized gasses, hundreds of thousands of distribution points world wide, and 100 and more years of know how in the production and distribution of volatile and dangerous fluids. Someone, like say, the OIL COMPANIES!

    I'm always amazed that so many people seem quick to condemn the oil companies as "huge, evil, earth destroying" corporations, and that they somehow think that changing to a new form of fuel will suddenly destroy the oil companies and bring in new immaculately clean and excessively environmentally conscious organizations. These people live in dreamland! It will take many years, and trillions (at least) of dollars to make any such change in our energy usage patterns, EVEN IF EVERY SINGLE PERSON IN THE INDUSTRIALIZED WORLD AGREED TO DO IT. And you still need people with the know how to design, build, maintain, fund, and expand these new systems. The oil companies of today will be around for a very long time to come, even if they change their primary product lines.....

  • People are attacking the emissions problem, because that is the feasible solution. The parts that are disposed of regularly (like tires, the cars themselves, used oil, etc) can be efficiently and cheaply (relatively) recycled, cleaned, or converted at centralized, enviromentally sane facilities. Millions of vehicles dumping emissions into the atmosphere can not. It is also the largest pollution component in transportation: the sum total of all pollution from other sources is positively dwarfed by emissions.

    If you want to reduce vehicular polluiton, the only real alternative to attacking emissions at the tailpipe is to outlaw driving...which will result in an economic and social and moral disaster the magnitude of which is unimaginable. It isn't going to happen, so you ought to do what you can, where you reasonably can.

  • And as a bonus, we wouldn't be dependent on nutty middle eastern dictatorships with delusions of mediocrity to run our cars. Air, last I checked, was fairly commonplace.

    Air may be commonplace, but hydrogen is not so commonplace. There is not much hydrogen in the atmosphere. Free hydrogen rapidly escapes the atmosphere, as its mean velocity at all temperatures in the atmosphere exceeds orbital escape velocity (cf. Jeans Escape) If you want to utilize hydrogen as a fuel, you have to make it and pick it up somewhere, since you won't be finding it in sufficient quantities in your intake manifold to be useful.

  • Interesting attitudes. Could you tell us something about the safety protocols around liquid oxygen? Seems to me that would be a lot more dangerous than liquid hydrogen. What about CO2?
  • You're talking out your ass, Pinto man.

    Why do you think gasoline, yes, gasoline, the stuff you can easily make napalm out of, so much safer than hydrogen? Never mind the fact that the Hindenburg blew up becuase it was coated with fscking rocket fuel. Never mind the fact that if the fuel tank ruptures, hydrogen will float upwards and disperse quite nicely, while gasoline will pool around and burn slightly less nicely. Never mind that while gasoline prices are constantly rising, LO2 is one of the cheapest fluids out there, and along with other gasses can only get cheaper as usage increases.

    Did you read the article? That hydrogen fuel tank is armored, man! If you you are involved in something that breaks it, you've got bigger problems than crummy H2.


    I would buy one of these in a heartbeat, if I could get H2 easily.


  • Well, Hydrogen has 3 times as much energy per unit weight as gasoline. But you can't get it as dense as gasoline, even in liquid form (1/10th), so it has less power than gas per unit volume. Thus you need the 140 liter H2-tank featured here.

    Come up with a way to compress it further, and you're golden.


  • My bad. I was thinking of LO2 when I wrote the air part. Still, to get hydrogen you just need water, also much more commonplace than oil.

  • The simple economic fact is: You will put more energy into creating the hydrogen fuel than you can ever get out of it since 1) entropy rules all energy transactions, and 2) the efficiency of a fuel-burning combustion engine is ultimately limited by the Carnot efficiency of the engine, which states that you can only get the working fluid to expand from its previous state by the ol' PV~T rule. Therefore it will be at least as expensive as that many joules of electricity, which is that many tons of coal, air, or wherever the hydrogen plant gets it from.

    The only reason that drilling for oil is cost-effective is that there is more energy contained in the product than it takes to get it out. Obviously. The same for coal, natural gas, and even wind turbine energy, etc... Once the return on investment slips to a lower level than is profitable, the energy companies stop mining it.

    How is this supposed to be different with hydrogen? Can someone with a calculator please tell me how much a mile of hydrogen will cost in terms of kW-hours of electricity? I suspect that it can't be more effective than the ol' 13.6 joules it stores and releases...

    When I took Direct Energy Conversion in college we talked about hydrogen, but only in terms of electric fuel cells, i.e., battery-powered vehicles. This is because the specific-energy stored in a cell (energy per unit weight) was much higher than lead-acid batteries (you need a trunk full of Pb batteries, and then your pickup and go suffers terribly due to all the weight).

    But, remember that it is never a question of 'creating energy', only moving it around, and entropy is there at every step, robbing the transaction of precious joules. So, it is really a case here of plug-in cars, just like the flywheel concept and the battery-driven vehicles.

    But perhaps Dean Kamen can help us gain economic feasibility of hydrogen where all but the Kaiser failed? Why are we not talking a little more about that, anyway? That is fascinating stuff, IMO...
  • The oil giants, Exxon, BP, Texaco, etc...are rapidly attempting to portray themselves as energy corporations. In the event of a switch to a more modern power source, they will be ready to jump in and provide much of the power and infrastructure that is needed.

    I think that the smaller drilling and prospecting firms are the real lobbies that will keep us stuck to fossil fuel dependence. With Dubya, proud CEO of multiple failed drilling operations, at the helm, the lobbies of these smaller companies will have a great effect on standards and federal research effort.

    I don't think OPEC will keep us dependent as the entire world would love to force that cartel out of business.

    Although it may seem strange (and to many libertarian minds quite unethical), the best way to move society towards clean sustainable power is to toughen emission standards. The trucking industry will always cry out that this will make profit impossible. The effect of this is to unbalance the economic playing field in such a way that clean == profitable. This effect was noted in the 70s when new emissions standards transformed the auto industry. You can thank your 35 mpg sportscar on these efforts. New standards, if they ever go through, will immediately lead to hybrid and fuel cell cars with 70+ mpg initially, and over 100 mpg later (or whatever equivalent metric fuel cells use).

    The large cap corps can predict and move with these changes, causing at most a 3 year dip in margins and stock prices.

  • BMW, and other manufacturers, need to investigate the possibility of creating hydrogen from water in the vehicle, not at the filling station or earlier.

    I'd definitely buy a car that can be refueled by dragging the hose around the side of the house and sticking it into a tank. It gives new meaning to the term, "Free car wash with every fill up!"

    Imagine the savings. What is water, a few cents per gallon in cities? In rural areas, it's absolutely free, because people have wells dug for them. Suddenly my monthly autmobile-related bills drop dramatically.

    Furthermore, since water is nonvolatile, it could be stored in every feasible spot--in the door cavities, in the engine compartment, in a regular tank, in the roof. All one would need is a small pure-hydrogen tank, and the water-hydrogen conversion could be done in the last few stages of the energy consumption chain.

    217 miles isn't a bad range at all for these cars... my '98 Contour gets 280-320 miles per fill up. This is much better than the 60 mile range the EV-1 sports, and with hydrogen refueling stations where every gas station used to be (assuming my ideas above don't come to fruition), America could survive with cars that get 220 miles per tank.

    I'd like to see this succeed... it would make cheap, clean transportation available to the masses, and there are no real crippling problems that other technologies bring.

    A new year calls for a new signature.

  • I think you are missing the point. With tanks available to hold separated hydrogen and oxygen, the conversion from water to gas can happen slowly.

    To effectively power an automobile, one needs to convert chemical energy into mechanical energy rapidly. This is done by exploding hydrogen in a combustion chamber.

    Of course decomposing water takes energy. But the process can be drawn out, and the results can be stored in tanks until they are required. One could rely on battery power, or solar power. It would even be possible to plug your car into a wall socket to separate water into hydrogen and oxygen. This would probably be the easiest, most reliable, and second most economic option.

    In addition, if you like, the car can be converted into a generator when it rolls downhill, decomposing water when it is not being forcefully driven.

    The point of this is to eliminate the need for hydrogen fill stations, and excessive stores of explosive hydrogen kept in public places. It also makes fuel readily and cheaply available. It is not necessary to have a dense fill station infrastructure to make the hydrogen-powered car economically feasable, and I'm sure the water coming out of a garden hose is cheaper than the hydrogen at the Munich fill station.

    Am I stupid? Of course not. I'm not proposing perpetual motion here. I simply expected any half-intelligent creature to understand that another energy source would be readily available to decompose water.

    A new year calls for a new signature.

  • This is not a flamebait. This is the math on typical solar collection and full size electric vehicle power requirements. Most fuel cell cars need a fuel cell in the 12-25 KW range giving them poor acceleration. Adding the weight of a bank of batteries increases the vehicle weight so the higher acceleration power is needed to make it onto a freeway ramp.

    Q How much power can I get from sunlight?

    A typical 2 ft X 4 ft solar panel is about 65 watts. If you can park in the sun for 8 hours you will collect about 500 Watt hours.

    How much power does it take to drive a sporty car on the freeway?

    Accelerating onto a freeway, about 100,000 watts. Divided by 60 minutes shows a consumption of 1.667 KWH per minute. Cruising on the freeway, about 12-25 KW uses about 200-500 KWH per minute.

    Q How far can I go on a day's sunlight?

    A About 1/2 mile at expected performance.

    For references, look up electric vehicles and fuel cell cars in google.

  • by SirDrinksAlot (226001) on Saturday March 17, 2001 @06:22PM (#356842) Journal
  • Where can I pick up my hydrogen-powered hovercraft?
  • Honda's car uses a fuel cell to generate electricity, for what is essentially an electric car. BMW's car uses an internal combustion engine and can also run on gasoline. Similar ultimate goal, different technology.
  • the common availability of liquid Hydrogen would allow some really cool do-it-yourself experiments and engineering projects

    ...but only if you overcame some pretty elaborate interlocks, I'd bet. The safety regulations surrounding hydrogen are rather draconian.

    Trucks which carry liquid hydrogen are not allowed to have safety valves. I am not kidding. They are not allowed to vent into the atmosphere at all. They carry portable refrigeration equipment to extend their range but each trailer has a finite range in hours, which is stamped on its side, depending on its insulation characteristics and the efficiency of its portable reefer unit.

    A plant operator told me that one truck went off a cliff in North Carolina. It was lifted onto a flatbed trailer and carried at high speed to its final destination, where it was offloaded, instead of having its load transferred into an unwrecked trailer.

    Another hydrogen truck was involved in a messy accident on I-10 in the town of Slidell, near New Orleans, not long ago. Particularly charming was the fact that a car was crushed beneath the trailer and burned there. This trailer was offloaded in the field, but they evacuated a 1/2 mile perimeter around the site and shut down the Interstate for half a day.

    It is worth noting that it takes significant BTU's just to cool the hydrogen down if you intend to store it in cryogenic form. This becomes an important part of its production cost. And while it may be relatively safe, the authorities here certainly don't think so.

  • My company services one of the plants which provide hydrogen fuel for Space Shuttle launches. 100% of the hydrogen used by the STS comes from petroleum. While you could electrolyze water to get hydrogen fuel what is currently practical is to crack petroleum in the same way you crack it to get gasoline. Naturally this does not have a very good yield compared to gasoline production, since it leaves the entire carbon content of the original petroleum as byproduct. (Guess where this carbon generally ends up.)

    Hydrogen fuel advocates are assuming, perhaps correctly, that once economies of scale are applied to hydrogen that more long-term and large-scale production methods will become practical and economical. But it hasn't happened yet.

  • You can "tinker" your own car and get a little extra mileage with just a little bit of acid and water and these plans []. Basically, it runs a current through the electrolyte-filled water, causing it to electrolyse into Hydrogen and Oxygen gas. These go boom and you go faster. (don't worry, it's a little boom.)

  • See... we'll make some hydrogen powered generators to create the hydrogen we need to power the hydrogen powered cars. Then to power those generators, we'll make even bigger hydrogen powered generators... and then bigger... and bigger! Amazing! Oh... and imagine a beowulf cluster of these things.
