First placed on the Internet in August 2003
First, it will be WONDERFUL if and when battery-powered vehicles and/or hydrogen fuel-cell-powered vehicles become economically practical. Neither seems very likely during the next thirty or probably fifty years, until and unless some great breakthroughs are found in energy production.
Sadly, many slippery people are now promoting devices that they claim have miraculous capabilities, which they certainly get a lot of people to send in money for! I have seen promotions for products that allegedly use hydrogen to produce 200 watts of electricity; that claim to create hydrogen to burn in a standard car engine; that claim to produce as much as a liter of hydrogen per minute; that claim to produce several times as much power in hydrogen as is allegedly used up in making it! (This last is a violation of the Conservation of Energy, but the promoters and business operators claim that they do not need to use standard laws of science, even though none of them has any College Degree!). If you are in the market for such things, I suggest that you keep in mind that NASA spends more than a million dollars for the 200-watt hydrogen fuel cells they use to produce electricity on satellites! (Oh, 200 Watts is about 1.4 of ONE horsepower) And you really believe that some joker is willing to sell you an equivalent system for a hundred dollars?
On first glance, Hydrogen seems to be the ideal fuel for automobiles and other vehicles. It doesn't seem like one could get any cleaner burning, since hydrogen burns (or oxidizes) to form simply water vapor. Nothing else! No pollution! What a seemingly incredible advancement over our current internal combustion engines that put thousands of tons of pollutants into the Earth's atmosphere, and their many other environmental problems. Did you know that EVERY gallon of gasoline you burn up sends around 18 pounds of carbon dioxide into the atmosphere? note 1
Hydrogen (H2) plus Oxygen (O) makes H2O, water, or actually, water vapor, at higher temperatures. And Hydrogen is actually capable of NEARLY meeting those high expectations.
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There IS a concept, and somewhat of a device, called a Fuel Cell (originally conceptualized in the 1830s), which can use the chemical reaction of hydrogen combining with oxygen from the atmosphere to generate electricity. THERE IS NO BURNING AT ALL in a Fuel Cell! It is entirely different. During the 1960s, NASA developed Fuel Cells which produced electricity for spacecraft. They worked reliably and fine, but they were horrendously expensive. There have been people trying to make inexpensive versions ever since! In the early 1990s, some breakthroughs were found. The concept of a Fuel Cell is actually pretty simple. You provide a supply of hydrogen gas and oxygen gas (which is usually from the air) which are separate, with a unique barrier between them. The simplest version of a Fuel Cell is to allow the (small) NUCLEUS of the hydrogen atom to pass through the barrier while not allowing the electron to also pass through. The electron is then caused to follow some DIFFERENT path to eventually get to where the nucleus had gone to, where the end result will be water molecules. Electron are negatively charged, and when they are forced to follow that alternate path, they are MOVING CHARGES which is the same as an electric current. In words, it therefore seems quite simple to have a Fuel Cell produce electricity. However, in practical terms, there are lots of complications! It may still be ten or twenty years before any reliable technology will exist which has tolerable cost.
And WHY is a Fuel Cell such an attractive thing? Why not simply try to BURN the Hydrogen in a conventional engine? There are actually two major reasons. The central one is that modern internal combustion engines only have an overall efficiency of around 21% (up from around 15% in the 1970s), while the fuel cell process has the THEORETICAL CAPABILITY of being nearly 100% efficient (although existing million dollar ones are generally around 40% efficient). The second reason is that Fuel Cells provide a CONTROLLED OUTPUT of (electrical) power. In an internal combustion engine, the oxidation of Hydrogen could and would occur in two VERY different ways! The desired one is by Combustion (technically, Conflagration), where the laminar flame front speed is around 8 feet per second at standard temperature and pressure. The undesired process is by Explosion (technically, Detonation), where the flame speed is over 9,000 feet per second, many times the speed of sound and incredibly dangerous! You might notice that NO experts really ever talk about using Hydrogen as an actual FUEL for existing engines (although there are many less educated people who talk about that a lot!) These are the reasons for that! (A few experimental engines HAVE been built to burn Hydrogen in a modified, very small internal combustion engine, but they have not really impressed anyone.)
As to Fuel Cells, NASA built theirs to provide MODEST amounts of electricity to power electrical devices in satellites. IF a fuel-cell was intended to power even a medium-sized car, more than 50,000 Watts of power are sometimes needed. A fuel-cell which might produce electricity at two volts would then need to create and move 25,000 amperes of electricity. Your great-grandchildren MIGHT see such a device some day, but it is inconceivable that you ever will. Yes, people get themselves on TV by doing a demo where they produce a couple Watts of electricity with a Fuel-Cell, and everyone gets excited. They shouldn't. The Reporters never know the right questions to ask about such future technologies, and neither does the public.
But Hydrogen itself has an ENORMOUS disadvantage, as well as many smaller ones. It cannot really be considered a "fuel" at all! Yes, it IS, but it isn't! It IS because of the exothermic chemical reaction described here. It ISN'T, because it does not occur naturally. We have such an attachment to petroleum and natural gas and coal and uranium BECAUSE they exist naturally. We actually have the technology to manufacture petroleum, but it would be so involved and expensive to do that it would never be worth it. Hydrogen is very different. It is so chemically reactive that it IMMEDIATELY combines with nearly any other atom (ion, actually) that happens to be near it. So there is NO natural supply of Hydrogen, anywhere on Earth. There cannot be!
This really changes the equation A LOT! Essentially, Hydrogen should be considered to be similar to a battery, where electricity is produced somewhere else and then STORED in it. And it turns out that the chemical and atomic properties of Hydrogen are such that it is rather difficult to pull hydrogen atoms out of any of the molecules that it exists in. That means that a lot of power is needed to separate out the hydrogen. In a sense, that is a reason why it is attractive! If a LOT of energy is needed to separate it out, then the SAME LOT OF ENERGY will get released when it is able to recombine. (The Conservation of Energy is involved here.)
It turns out that there are ways that methane gas can be combined with very high temperature steam, with a special catalyst, where Hydrogen is produced. THAT is the process by which around 95% of American Industrial Hydrogen is produced. Unfortunately, it not only uses the fossil fuel methane as chemical stock material, but the process required very high temperatures, which uses up even more fossil fuels.
For each pound of Hydrogen produced from methane, over 9 pounds of carbon dioxide is created and released into the atmosphere. (plus the by-products of the fossil fuels burned to create the heat needed). Since around two pounds of Hydrogen gas is needed to equal the energy in a gallon of gasoline, this means that the process for creating Hydrogen from methane gas produces roughly the SAME amount of Global Warming carbon dioxide as did the gallon of gasoline being replaced! That is NOT Green!
One obvious primary source of Hydrogen is water. That process does NOT give off any carbon dioxide. However, it requires really large amounts of electricity to drive the process, and the creation of that electricity in a distant powerplant (usually by burning coal) gives off a lot of carbon dioxide as well. These concepts that are allegedly so Green, really are not!
Here is part of a paragraph from the Grolier Encyclopedia:
Electrolysis is an energy-consuming process. To obtain 2 grams of hydrogen and 16 grams of oxygen by the electrolysis of 18 grams of water, the equivalent of 68,300 calories of electrical energy must be supplied. This same quantity of energy, however, can then be recovered from the hydrogen and oxygen, either suddenly in an explosion or slowly if they are brought together in a FUEL CELL.
Two grams of Hydrogen is only 1/227 pound, so the electrical energy actually required to produce a pound of Hydrogen is therefore 68,300 * 227 or 15,500,000 calories of electrical energy! This can be converted into 18,000 watt-hours or 18 kWh. As noted below, the existing technologies to create Hydrogen by electrolysis are all around 20% efficient, which means that around 100 kWh of electricity is used up to produce a single pound of Hydrogen gas. Note that you need to use up 100 kWh of electricity to have 18 kWh of electricity or energy available in one pound of hydrogen gas!
If a house's present 15-cent per kiloWatt-hour of electricity is used, that (100 kWh) therefore would require at least $15 of house electricity to be used up to create that single pound of hydrogen gas! We will see below that one pound of hydrogen gas contains just under half of the chemical energy of a single gallon of gasoline, so, even if everything else was perfect, more than $30 of modern house electricity would be required to simply PRODUCE an equivalent amount of Hydrogen gas to one gallon of gasoline! And then that gas would have to be ferociously compressed and all the rest.
Notice that we have implicitly referred to the Conservation of Energy here. We had to USE 100 kWh of electricity to MAKE the pound of Hydrogen, but it can only RELEASE the 18 kWh of energy which it can contain. This is a "detail" regarding Hydrogen that no one ever seems willing to mention! We just saw that even if we were only going to try to compete with house electricity, We would have to use $15 of electricity to make the Hydrogen which could replace only 18 kWh or $3 worth of electricity. Would anyone seriously think that sort of thinking would represent any possible SAVINGS?
Some visitors to this page seem to be unfamiliar with science and Engineering but they each insist that they can make huge amounts of hydrogen, and they always also say cheaply and easily. We might examine some flaws in their thinking here. Let's say they intend to make just ONE KILOGRAM of hydrogen gas. This would contain roughly the same chemical energy as a gallon of gasoline. This kilogram of hydrogen gas normally takes up around 450 cubic feet, about the volume of your bathroom. Traditionally, ferociously powerful compressors are used to squeeze the hydrogen gas into about 1/200 of that volume, which also increases the pressure of the resulting compressed hydrogen up to about 3,000 PSI pressure. The only way to store any gas at such extreme pressure is in extremely thick and sturdy industrial tanks. A standard K-tank can contain around one pound of hydrogen gas, so you would need a little more than two such tanks to store the one kilogram. Each tank also weighs about a hundred pounds, so for just one gasoline-gallon-equivalent, you would need to haul around an extra 300 pounds of tanks! We also just discussed the amount of energy needed to chemically separate out hydrogen from water, which is around 35,000,000 calories of energy for the kilogram of hydrogen we propose to produce. And since the process of Electrolysis is not particularly efficient, you actually will need to find around 175,000,000 calories of energy (probably as electricity) to power the separation of the hydrogen from the water. That is a LOT of energy. Actually, as also noted in the above comments, IF you go to all that expense and trouble to have a kilogram of compressed hydrogen gas, the Conservation of Energy requires that all that 35,000,000 calories of energy have to be released when the hydrogen again combines with oxygen to form water, which is the really attractive feature of hydrogen. If there were free lunchs, it would be great, but one must first PAY (in energy) to produce the hydrogen. The resulting hydrogen then does not magically produce lots of energy, it merely RELEASES the energy which you had previously put into it!
It is actually a LOT cheaper and easier to BUY tanks of compressed hydrogen gas, which had been made by using the methane method, but that turns out to be dozens of times more expensive than in buying gasoline!
Down below, we will see that the lowest quality of Industrial Hydrogen was sold for around $42 per K-tank (per pound) in 2003, which actually represents a fairly attractive pricing! (Note that meant that in 2003, the two pounds of Hydrogen necessary to have the same amount of chemical energy (126,000 Btus) as one gallon of gasoline would have involved TWO K-size tanks and cost around $85!) In 2006, the price was still about the same for a K-tank of compressed Hydrogen. This price is in a DELIVERED form, of standard high-pressure tanks, called K-size tanks, which is how one can buy one pound of Hydrogen gas at a time. However, in really large quantity, such as full (very high pressure) tanker truckloads, the recent price publicized is generally around $3 to $5 per CCF (hundred cubic feet) of Hydrogen, but that price is FOB, meaning that the cost of freight shipment in such a truck is added on. The point here is that there is an extremely wide range of possible costs for Hydrogen gas! Proponents of Hydrogen always cite the $3 to $5 per CCF, which means $6 to $10 per pound (200 cf) of compressed Hydrogen gas, or $12 to $20 for enough Hydrogen gas to contain the equal energy as one gallon of gasoline. But after all the massive storage tanks are bought or rented, and the freight is added, and then the handling and storage charges of a local industrial warehouse, even under these BEST conditions, the final price of the Hydrogen to the customer seems certain to be at least $40 (for enough Hydrogen to equal the energy in one gallon of gasoline.) The promoters and salespeople never seem to mention this, but even if relatively few middlemen try to profit from handling the Hydrogen, it is hard to see why many vehicle owners would be willing to pay $40 or $85 to buy enough Hydrogen to replace a single gallon of gasoline.
You noticed above that these high prices are primarily due to the impressive amounts of electricity necessary to separate Hydrogen from water or methane or any other molecule. Hydrogen is an element that binds VERY tightly in molecules! Actually, again, that is simply saying the Conservation of Energy again! If immense amounts of power is REQUIRED to separate it, then the exact same immense amount of power can be released when it is again allowed to join oxygen or other elements into stable compounds. There is nothing magical about that! It is ONLY because it is so hard to separate Hydrogen that it therefore contains so much energy as a potential fuel.
It would be fantastic if "free hydrogen" was all over the place to be collected and then used as fuel! No dice! It already released all that energy long before we were around, in securely bonding into those molecules.
And even these prices do not actually include all the final costs to a vehicle owner. K-size industrial tanks are NOT owned by the user, but instead RENTED, such that the tank owner can do the regular required testing to ensure that the tank has not deteriorated to a point of not being safe. (Demurrage) It figures that the US government would require MASSIVE testing of any 3,000 PSI tanks which are inside of vehicles on public highways!
In any case, we KNOW that you CAN get compressed Hydrogen locally from an Industrial Gas supplier, at roughly that $42 per full K-tank (which is one pound of Hydrogen gas at 3,000 PSI pressure). Should it turn out that you can obtain highly compressed Hydrogen gas at lower cost, it seems unlikely that you will ever get the full tanker truckload price, but you would be free to try to find the best price you can. This presentation is simply describing known facts. This presentation will continue with the KNOWN price which you are likely to be able to buy compressed Hydrogen gas for, the $42 per K-tank (which is produced from the fossil fuel methane gas).
Because of the problems of storage and transport of Hydrogen gas, around 95% of the Hydrogen that is currently produced, is USED right at that same location! Most of the remaining 5% is compressed or liquified down to near absolute zero, for transport to use at other locations. Much of the glowing reports that keep getting into the news are SPECULATIONS regarding future hopes, rather than any actual reality!
As of early 2011, Ford has some Fuel-Cell-powered vehicles being tested by drivers. They have their own supply source where the drivers can get more. Ford is experimenting with incredibly high pressure storage of the Hydrogen in the vehicles, at 10,000 PSI. Hopefully, none of those vehicles will ever be in an accident and none of the tanks ever fails. It seems unlikely that any vehicle to be sold could contain such high-pressure storage, as it has too great a chance of becoming deadly. No actual cost of those Fuel-cell-powered vehicles seems to be available, but hints seem to imply that each had cost Ford more than a million dollars to build! Fuel-cell-technology really does NOT seem likely practical for at least thirty or fifty years, or even more. Ford is incredibly mute regarding how much electric power those vehicles can produce. My personal guess is that one or two horsepower worth of electricity is likely. They also never show the PERFORMANCE of vehicles which might only have one or two horsepower available. An actual horse might out-perform them, I suspect! We might also note that the advances during the past 50 years, since NASA had developed the Fuel-Cells for satellite power in the 1960s, have not been very significant.
As with nearly all other subjects on the Internet, there are plenty of web-sites that present information which might APPEAR to be extremely attractive! One even claims to provide a GALLON of compressed hydrogen for less than a gallon of gasoline costs! Quite amusing. I wonder what their price is for "a gallon of dynamite" or "a gallon of Uranium" or "a gallon of potatoes"! But they are counting on the public to not be able to know that a GALLON of a COMPRESSED GAS is a meaningless concept! And they seem to also overlook the FACT that it requires a K-tank weighing close to 100 pounds to provide the necessary strength to contain even ONE POUND of Hydrogen gas compressed to 200 atmospheres (3,000 PSI)! A GALLON indeed! Such statements are only made by people who are ignorant of the actual scientific facts! And they are meant with the intention of totally deceiving the public. The sad thing is that there are a LOT of people who will read their stuff and believe that they actually know what they are talking about, and will give them money so that they could "improve" their products! It is too bad that the word SCAM cannot automatically appear in such web-sites!
Unfortunately, the Laws are such that they can get away with nearly anything in such claims! YOUR FINGER is composed (primarily) of carbon, hydrogen and oxygen atoms. You could therefore CLAIM that you have a "supply of hydrogen" available! And LEGALLY, that might be considered to be true, but PRACTICALLY, it is silly. To try to extract the hydrogen atoms out of any dead animal carcass IS possible, but both very difficult to do and also rather pointless! "Add a dead cat to your car's gas tank and get 100 miles per cat!" I'm surprised that no one has claimed that (yet)! (In the sense of brutal accuracy, a 7-pound cat's body probably only has enough actual chemical energy in it for around 20 miles max! And not much of that is in Hydrogen but rather in Carbon!)
They must certainly now regret asking that!
Their web-site is pretty and attractive. It starts off referring to a Patented Bio-Reactor (impressive sounding, huh?) which produces hydrogen by using algae. Four hundred years from now, I have little doubt that algae WILL be used to generate electricity, and possibly even hydrogen. But not in OUR lifetimes, except on a tiny scale in a laboratory.
They then decided to use BOLD type to express an outrageous claim: "Enough to power two cars and the electricity in your home"
I should now point out that their web-page ended with a very prominent request for investors in their company! THAT was essentially the central reason for the existence of that web-page!
They happen to mention that their current device can produce 8.4 liters of hydrogen during light periods. Weird wording??? They are actually saying that if a day is completely sunny, 8.4 liters can be produced. Fine. And to the public, I guess that sounds impressive! What they do NOT say is that one pound of hydrogen takes up nearly 200 cubic feet or about 5.5 cubic meters. One liter is 1/1000 of a cubic meter. So what they are ACTUALLY saying is that IF there are about 650 consecutive totally sunny days, their system should be able to produce ONE POUND of hydrogen. (In England, it is RARELY really sunny!) But they are ACTUALLY claiming that within a few years of full operation, their equipment could produce one pound of hydrogen gas. And after a few more years, they might have TWO pounds of hydrogen gas, which happens to contain about the same energy as one gallon of gasoline!
The impressive sounding statements in that web-site probably do not seem so impressive to you any more???
In a rather brief web-page, it is disappointing to see misspellings!
Sadly, there WILL be people who read that web-page and decide to INVEST in their company. Thinking that the company actually has some brilliant insights or inventions or knowledge.
One real disadvantage in using algae to produce either electricity or hydrogen is the fact that the photosynthesis process used by the algae is only about 1% efficient in converting incoming solar energy into glucose. So even before the glucose is used to be chemically decomposed into constituent chemicals, there is a real disadvantage regarding overall efficiency. But it IS GREEN! Again, in maybe 400 years, I am confident that algae will be a prominent method of producing the power we then use!
The main point here is that there are endless web-sites which now exist which provide SELECTED information, which is all meant to MISLEAD readers into either wanting to buy something or invest in some company.
Several years back, a group of people in Southern California aggressively tried to get me to either be part of their research or to endorse their research. They admitted to me that they wanted me mostly because I AM a scientist, as they admitted that none of the rest of them were! Yet, they considered themselves to be experts in hydrogen! In their efforts of trying to get me to join their efforts, they even told me of "independent proof" that their process did all they claimed. They eventually even provided me with a "lab report" by that (alleged) test laboratory. It was amusing to see (alleged) results which claimed to produce around FOUR TIMES as much energy in the (alleged) created hydrogen than they ever claimed to need to use to produce it! Any actual scientist would find that laughable, as it claimed to be an extreme violation of the Conservation of Energy!
When I pointed that out, they told me that they had advanced BEYOND science, and that they did not NEED to meet any of the requirements of any accepted scientific laws!
I then told them that IF they had actually done what they claimed, then why not take that FOUR TIMES THE ENERGY that they claimed to create and use that energy to produce 16 times the original energy used? And then again to produce 64 times, and then 256 times, and then 1024 times, etc. Shoot, in their little laboratory with such a magical process, they could obvious quickly produce more electricity than the entire world could ever need! Who CARES about silly ideas like the Conservation of Energy?
They actually did not easily give up! Over the following year, they contacted me twice again, finally admitting that their device still needed refinements, and that they needed investors to give them several million dollars so that they could continue. So they wanted to use MY REPUTATION in order to deceive potential investors into believing that they had any idea what they were trying to do! Imagine, a group of people with NO Science or Engineering education, or any background in any related fields, and who did not even accept the universally accepted scientific laws! And you know what? I suspect that there WERE probably gullible people who probably gave them the millions of dollars they wanted.
As long as the "victim" (my term) does not know enough to know whether the "con artists" (my term) were telling truths or exaggerations or lies, and if they can come across as SMOOTH enough, didn't Barnum once say that there's a sucker born every minute?
So THIS presentation DOES NOT TRY TO SELL YOU ANYTHING! It is intended ONLY to try to provide you with some accurate and correct information for WHEN you get confronted with such spectacular and impressive claims of magical solutions.
Peak Power Rating vs. Average Power Rating|
You may drive a car which was advertised as having a 495 horsepower engine, and that may have even affected whether you bought that specific car. That engine rating can be called a PEAK POWER RATING, being the greatest amount of power that it is capable of producing. When creating that enormous amount of power, it is realistic to expect to get around one or two MPG gas mileage. But for AVERAGE driving on an Interstate Highway, your engine only produces around 40 horsepower, during which you may get 25 miles per gallon gas mileage. This AVERAGE situation is a far more accurate description of what YOU CAN ACTUALLY EXPECT, such as regarding gas mileage. Both situations are true, but they are extremely different. One is a situation which sounds very impressive, but which you will likely NEVER actually experience, except possibly rarely for a second or two at a stoplight! The other is a situation which you may experience every day of driving! IF you were only given ONE of the numbers, which would you consider more important to know?
Whenever electricity ratings are given for alternative energy devices, they seem to always be PEAK POWER RATINGS, meaning the greatest amount of electricity or power which can be created. That is entirely different than ratings for AVERAGE USAGE CONDITIONS, which would be realistic numbers of amounts of electricity or power which might NORMALLY be expected to be provided. The discussion and calculations included here will indicate that OFTEN the realistically expectable amounts of electricity or power is only around ONE-TENTH that of the PEAK POWER RATINGS. But no one bothers to mention this important fact! So advertising makes claims of spectacular performance numbers for photovoltaic solar-electric panels, and for solar roof panels, and for electric vehicles, and for Hybrid vehicles, and for windmill-electricity-generation, and even for FUTURE giant windmills and hydrogen as a fuel. They invariably state PEAK POWER RATINGS, like that 495 horsepower engine in the car, numbers that may be technically true but are extremely misleading.
You can look up something called the Electrochemical Equivalent of Hydrogen in many Reference books. It is the amount of electrical energy that exists in the chemical bonding of Hydrogen atoms inside of the molecules it exists in, such as water, H2O. Those Reference books show that 12,062.183 ampere-hours of electrical energy is required to release a single pound of Hydrogen from any chemical compound. This is a LOT of energy! It turns out that there are no "perfect" devices to do this, and the best tend to be around 20% efficient at getting the Hydrogen released, regarding the electricity used. So we actually need to use up around 60,000 ampere-hours of electrical energy in order to get one pound of Hydrogen released (and therefore available as a fuel). That is a LOT of electricity! Your kitchen toaster uses around 15 amps of electricity, for maybe 30 seconds. Here, we are talking about 100 amperes of electricity being used continuously for 600 hours or 25 days!
So, proponents of "the coming Hydrogen economy" brag about the fact that Hydrogen CAN be produced by electrolyzing water to separate it into Hydrogen and Oxygen gases. Then they brag about the fact that when Hydrogen burns, it combines with Oxygen to create "lots of power, and just water vapor". Those statements are totally true, and nearly everyone seems to totally trust the people pushing Hydrogen and Fuel Cells, without asking the next, VERY IMPORTANT, question! Didn't the First Law of Thermodynamics prove to us that we cannot have energy simply appear? That there is a Conservation of Energy? So, if we have to SEPARATE the Hydrogen from the water to start with, doesn't it seem obvious that it has to require AT LEAST AS MUCH energy as will later be released when the Hydrogen again winds up as part of water? How come nobody asks this really obvious question???
In fact, there is another closely related Law of Nature, regarding something called Entropy, where NO actual process can be 100% efficient. So, as discussed below, to provide all that electricity needed to release Hydrogen from any chemical compound and then store it: (1) coal must first get burned in a power plant; (2) it must heat water into steam; (3) that steam must drive high speed turbines; (4) the turbines must drive alternators [down to about 30% of the coal's energy left at this point]; (5) the electricity must then travel through wires and transformers to get to your house [down to about 13% of the coal's energy left at this point]; (6) an electrolysis apparatus must use (a LOT of) electricity to produce Hydrogen gas [down to about 2.5% of the coal's energy left at this point]; (7) that gas must be tremendously compressed to be of manageable size; (8) THEN you finally get to the Fuel Cell technologies that are still being developed!
The result of this is that Hydrogen power for vehicles might SOUND amazingly Green, but the reality is that the power consumed [fuel burned] (at that distant electric power plant that you never see) to create the Hydrogen is at least six times the amount of power associated with a gallon of gasoline! This results in that distant electric power plant burning around six times as much coal and converting it into carbon dioxide as when a vehicle simply burned gasoline in its engine! (Linked web-pages to this one give the specifics where a gallon of gasoline burned in a vehicle produces around 18.3 pounds of carbon dioxide which gets released into the atmosphere. Due to those steps enumerated above, around 37 pounds of coal must be burned in an electric power plant, which releases around 108 pounds of carbon dioxide, to produce enough electricity to provide enough electric power to match the performance of one gallon of gasoline. Currently, producing Hydrogen is even worse than this, because current technologies to decompose water are nowhere near being efficient! So at the very BEST, these supposedly GREEN technologies cause AT LEAST SIX TIMES AS MUCH carbon dioxide to be released (at that distant power plant) than if the original gallon of gasoline was burned as always!
For now, no one seems willing to tell the public these things, because they REALLY want to get the public to eventually buy a zillion Hydrogen powered vehicles! This exact same situation occurred some years back (in the 1980s and 1990s) when Battery-powered vehicles were supposed to be the FUTURE! Battery power is GREAT, IF you only consider the vehicle itself. It gives off ZERO pollution! But these same issues regarding the massive amount of electricity needed to re-charge those batteries (even for golf carts) already costs about as much as what the equivalent amount of gasoline would have cost! And at the distant power plant where that electricity was produced, a LOT of pollution, MANY TIMES MORE, carbon dioxide and atmospheric heat was created and released. You just don't see it! Ditto, with Hydrogen!
It seems fascinating that two technologies that are promoted as GREEN, battery-powered electric vehicles and future hydrogen-powered fuel cell vehicles) are each horrendous when the whole picture is examined, because that distant power plant has to burn ferocious amounts of coal to produce that much electricity! And the many people who optimistically think that they will be able to use a few solar panels or a small windmill to produce a hundred amperes of electricity for 25 constant days to generate one pound of Hydrogen? I have a Bridge in Brooklyn that I think you may want to buy!
There is a more technical name for this relationship. It is called the Electrochemical Equivalent. For hydrogen, one can look up that value in many reference books, as being 12,062.183 ampere-hours per pound. One can easily see that at a rate of ten amps, the 1206 hours is slightly over 50 days, as noted just above. With actual existing equipment, around 250 days of continuous use and consumption of a lot of electricity, just to produce that one pound of Hydrogen.
People who promote hydrogen seem to imply that by simply snapping one's fingers, all sorts of hydrogen can be obtained! Note that many of these comments and calculations just above had assumed that all equipment was perfectly efficient, which is never even close to being true in real life. YES, they are technically correct that you could take a glass of water from your kitchen tap and generate hydrogen gas from it by electrolysis, which might then be used as fuel in a vehicle. But see that they have sort of left a LOT of important details out?
In principle, they could also have said that that same glass of water could provide most of the power needed by the entire United States if it was processed in a Fusion Reactor (the way the Sun operates, but which appears to be far beyond anything we can build). Such statements are technically true, but incredibly misleading because of the many practical matters which were not mentioned!
In addition to NOx production, if the device in which the burning occurs has any lubricants, like oil, there are also oxidation products of the Carbon in them, which can contain CO, carbon monoxide. When Hydrogen is burned in a decently designed (laboratory) device, these environmental problems are fairly minor and they are rarely considered to be any great danger.
I said laboratory here because the great difficulty and expense of generating significant amounts of hydrogen seems to have limited such experiments to laboratories so far. I am not aware of any actual products that use Hydrogen as the primary energy source, and it seems unlikely that any will exist until Fuel Cells are fully refined, probably decades from now.
However, a pound of gaseous Hydrogen is HUGE! At standard atmospheric pressure and temperature, it takes up around 190 cubic feet of space. In contrast, that pound of gasoline only takes up about 1/45 of a cubic foot. Hydrogen gas takes up around 9,000 times the space that the same weight of gasoline does!
For the record, we are NOT suggesting that gasoline is any great fuel source. It IS convenient, and compact, true. But it causes pollution of many sorts, including adding large amounts of carbon dioxide to the atmosphere which directly contributes to global warming. So this is NOT a fan letter for gasoline! It is instead intended to present an accurate scientific discussion of Hydrogen as a fuel, where all the press reports we hear in the news seem to always leave some really important stuff out!
Consider a mid-sized car, traveling at 60 mph down an Interstate Highway. It is well known (and easy to calculate) that roughly 40 actual horsepower is needed to maintain a constant speed. A horsepower is equal to 2544 Btu/hr, so we are talking about 102,000 Btu/hr of "actual" energy/work. For an hour's driving, we would therefore need 102,000 Btu of output energy, to ACTUALLY MOVE THE CAR THROUGH THE AIR AND WITH TIRE RESISTANCE. (A gasoline engine would use maybe 3 gallons of gasoline during that hour's driving [20 miles/gallon] which actually contained about 378,000 Btu of energy, but the engine/car efficiency is only roughly 25% to create the 102,000 Btu of output work.)
Consider now that a cubic foot of Hydrogen (not compressed) only contains 319 Btu per cubic foot. That hour of driving would therefore require (102,000 / 319) over 300 cubic feet of the Hydrogen! Notice that this does NOT refer at all to any engine or drive system, and is instead simply considering the Aerodynamic Drag of the vehicle pushing its way through the air at 60 mph and the Tire Resistance Drag due to the tire sidewalls flexing each time the tires rotate. The ACTUAL efficiency of existing vehicles being around 21% means that IF Hydrogen was burned as fuel in a vehicle, we would need to duplicate that actual 378,000 Btu of source chemical energy, and we would therefore need to use up (378,000 / 319) around 1200 cubic feet of Hydrogen for that hour trip. In case you are curious, a 10 foot by 15 foot living room, with an 8-foot ceiling, contains around 1200 cubic feet. THAT much Hydrogen would be necessary to be consumed for that single hour of driving!
We can say this same thing in terms of "gallons". A gallon of gasoline contains around 6 pounds, and has 126,000 Btus of energy in it. A "gallon" of hydrogen (gas) only contains around 40 Btus in it. Quite a difference! Instead of a two cubic foot gasoline tank (15 gallons) in your car, you would need a tank more than 3,000 times bigger, over 6,000 cubic feet, for the equivalent Hydrogen! That's a little more than TWO standard semi trailers (8'wide x 8'high x 45' long or 2900 cubic feet each). Pretty big gas tank!
Well, that is obviously not going to happen! So, the many ongoing explorations into using Hydrogen as a fuel always involve carrying HIGHLY COMPRESSED Hydrogen in very thick, heavy tanks. If you have ever seen the kinds of tanks used for the Oxygen for a worker's oxyacetylene cutting torch, that's the kind. Such tanks can hold Hydrogen at around 200 times atmospheric pressure, or 3,000 PSI, an extremely high pressure. When Industrial Hydrogen is purchased, it is bought in tanks like that.
Well, at 3,000 PSI, or 200 times atmospheric pressure, the Ideal Gas Law tells us that the Hydrogen (equivalent to a 15 gallon gasoline tank) would now only take up 6000/200 or 30 cubic feet. That works out to around 30 of those (fairly large) high pressure storage tanks (again, to match the effective capacity of the 15 gallon gasoline tank.) Each of those tanks (called K tanks) actually contain a maximum of about one pound of Hydrogen gas. Each tank is very massive to withstand the extremely high pressure, and each weighs nearly 100 pounds empty. (And around 1 pound more when filled with Hydrogen!) So the normal American car which presently weighs around 2800 pounds would have to have around an extra 3,000 pounds of those 30 high-pressure tanks added, so the vehicle would now weigh more than twice as much as current cars! (This tremendously affects acceleration, handling and other performance, and it would be like that car forever pulling a huge 3,000 pound trailer behind it.
Those 30 very high pressure tanks present another complication. If industrial workers ignore proper safety rules when working with a high pressure Oxygen tank (at 1500 PSI pressure), it could fall over. As the hundred-pound tank falls over, it quickly develops a lot of momentum. If there should happen to be something in the way on the floor, where the neck and valve of the tank hit it, the neck and/or valve has been found to tend to just snap off. Suddenly, 1500 PSI of compressed gas has an easy way out, and it all goes out almost immediately. Isaac Newton told us about the Law of Action and equal Reaction. The hundred pound body of the tank then zooms off like a rocket at extremely high speed in the other direction. There have been many industrial accidents where such Oxygen tanks flew many hundreds of feet through the air and passed completely through concrete walls!
Most suppliers of compressed industrial gases display photographs of vehicles where ONE such compressed gas tank had not been strapped down properly and the neck wound up snapping off. Usually, the vehicles shown in those pictures are hard to tell as being vehicles, except for maybe a tire somewhere in the picture. The results of that carcass of a hundred-pound oxygen tank zooming off like a rocket pretty much passes through whatever had been in its way. If the vehicle had been traveling at highway speed, it suddenly no longer has enough parts to continue as a vehicle!
Get the point? Imagine having 30 such tanks in a car. If even ONE vibrates loose from its clamps, or the guy who last replaced them didn't strap them all down properly, or an accident occurs where you hit another vehicle or a tree? If even one of those tanks ruptures, REALLY bad things would result. Given that Hydrogen tanks contain TWICE the pressure of Oxygen tanks, the effects of a tank neck snapping off is both more likely and also potentially more destructive. And have you ever even seen what happens to any NORMAL car when a semi hits it? Imagine if that target car had 30 tanks inside it which each were simply waiting to become unguided missiles!
Notice that this issue is not actually related to any hazard of Hydrogen itself, but rather the fact that it would have to be stored at extremely high pressures due to its very low density. Whether it was a high-pressure Oxygen tank or an even higher-pressure Hydrogen tank, this danger is virtually the same, and is entirely due to the pressure that the gas is compressed to.
Because of this extraordinary safety hazard, which is only due to the very high pressures involved and really has nothing to do with the Hydrogen itself, there is no imaginable way that the US Government would ever allow such vehicles to be generally licensed. It would conceivably be a lot safer to drive a dynamite truck!
Such equipment is difficult enough to operate when the gas being compressed is Nitrogen or Oxygen or Carbon Dioxide. But when it is also a potentially explosive gas such as Hydrogen, safety issues multiply. Imagine having the necessary compressor and pipes and tanks in a garage, and a tiny leak appears in one of the pipes. A spark or someone with a cigarette? Poof, no garage! Ever seen the Hindenburg disaster movie?
However, even if there was some way to do all that compression, it takes a good amount of electricity for the compressor motor to drive the compressor. A significant cost would be involved for that compression, even if you somehow had your own compressor.
In addition, free Hydrogen does not exist. All of the Hydrogen that might be collected is now in various compounds. The simplest to deal with is water. If you had Chemistry in High School, then you hooked up some electricity to an apparatus that contained water, and you saw little bubbles of Hydrogen form in one upside down test tube and Oxygen form in the other. That is called Electrolysis, or the Dissociation of water. It is obviously pretty easy to do.
But those are just little bubbles of Hydrogen that you collect. After a minute or two of such an experiment, you had a half-finger-sized bubble of Hydrogen gas in a test tube. A spark or flame, and POP, it exploded! And everyone laughed! But remember now that you are going to need an amount of Hydrogen that would more than completely fill two semi trailers, to just equal one tank of gasoline! It is possible to calculate the amount of electricity needed for that, but you must get the idea that it is a LOT of electricity! (We discussed some of that up above) So, you get to pay your electric company for that, too.
So, you would wind up paying for the electricity to Dissociate the water in the first place, plus the cost of the electricity needed for the extreme compression. Of course, all of this would be after you bought the necessary equipment! We discussed above that this will increase your electric bill by at least $30 (and likely much more) for the equivalent of one gallon of gasoline. Also, roughly 36 pounds of coal have to be burned at a distant electric power plant to produce that same energy that a single gallon of gasoline contains. Which causes roughly SIX TIMES the amount of global warming carbon dioxide (107 pounds) to be produced at that power plant than if you had simply kept driving the gasoline powered vehicle (18 pounds)! (See the Battery-powered vehicle presentation linked at the bottom of this page for the complete details on that.)
An alternative, of course, would be to buy (rent actually) tanks of industrial Hydrogen that is already compressed. Current prices (2003) for Industrial Hydrogen (the lowest purity available) are around $42 for a standard K cylinder, a very high pressure tank which contains 197 standard cubic feet of Hydrogen, plus a monthly rental fee for the tank. The 6,000 cubic feet that we had earlier determined were equal to one 15 gallon tank of gasoline, would therefore be around 30 of these tanks, which would cost around $1260 for (one gasoline tankfull!) the compressed Hydrogen PLUS the monthly rental of at least $300 for the tanks themselves. (Using the single gallon of gasoline scale we discussed above, you would need to buy/rent only two K-sized tanks, for around $85 plus cylinder rental costs, for the equivalent to that single gallon of gasoline.)
We complain today at paying $3 per gallon for gasoline, which would be $45 for our 15 gallon tank. How many people would be willing to pay $1260 and more for the same driving distance, using bought Hydrogen?
(NOTE: There does not appear to be available any data regarding flame-front speed for Hydrogen gas when compressed as in a car engine. Therefore, we add the following discussion, which also shows the sort of far more comprehensive Physics research that is the basis for essentially all the statements made in this presentation.)
First, everyone is taught in school that Hydrogen "simply"
combines with Oxygen in the familiar (2) H2 + O2
↔ (2) H2O. That turns out to be an enormous
simplification! There are actually 19 different chemical reactions that can
and do happen! Each releases different amounts of energy (with two of
them even REQUIRING energy to occur!). In general, two or more of
these reactions occur in rapid succession, with the end result of
the familiar reaction. Physicists and Chemists analyze ALL of those
19 unique reactions, in order to better understand exactly what
is going on and why. In fact, the overall reaction of Hydrogen
with Oxygen can occur in two VERY different ways! The DESIRED
one is by burning (conflagration) which has the flame-front speed
indicated, around 8 feet/second in the atmosphere. The UNDESIRED
one is by explosion (detonation) which has a flame-front speed
of 2,821 meters/second or 9,255 feet/second! That is around EIGHT TIMES
the speed of sound and many times faster than the fastest rifle
bullet travels! It is incredibly dangerous when Hydrogen decides
to detonate, and science does not yet have a very complete understanding
of why it sometimes does! Our discussion here will be about the DESIRED
laminar flame-front process.|
Next, the velocity of the (laminar) flame-front is known to be very dependent on many different variables. Here is an equation that gives the flame-front velocity (speed):
(There are actually three different theories which exist to explain the motion of flame-front travel and this equation happens to be from the one that seems to be the best. Many of the equations involved are far more complex than this one. They were generally developed during the 1980s.)
If a number of reasonable assumptions are made, this can be greatly simplified into:
The exponents are different for each type of fuel gas, and for Hydrogen they have been experimentally determined (Milton and Keck 1984) to be α is 1.26 and β is 0.26
Note that all of this is based on ideal conditions; the perfect proportion of fuel and oxygen; perfect mixing; etc, and that real conditions are often not ideal.
If we assume that an engine has an (actual) compression ratio of 8:1, the pressure increase factor therefore would be 80.26 which is 1.717. The natural flame-front speed of 8 feet/second would therefore increase to 8 * 1.717 or 13.7 feet/second. We note that some 2004 research in Bergen, Norway shows a maximum atmospheric flame-front speed for Hydrogen as 2.8 meters/second, which is slightly higher than the 8 ft/sec cited above at 9.2 ft/second.
This is still far slower than the measured flame-front speeds inside gasoline-fired internal combustion engines (which is generally at least 90 feet/second during most driving). However, the dependence on temperature causes some improvement in this situation. Hydrogen burns at 2,755°C or 4,991°F. The heating of the gas occurs gradually during the process of the combustion, but if we assumed that the hydrogen got up to that temperature, the temperature dependence factor in the equation above would be around 18 to one. This implies that the COMBINATION of the higher pressure and the higher temperature MIGHT cause a flame-front speed which is comparable to that known to be in gasoline-fired internal combustion engines. But it does not appear that anyone has yet actually done such experiments to validate that statement.
Consider the inside of an engine cylinder in a normal car engine traveling down the highway. The engine may be rotating at 2,000 rpm, or 33 revolutions per second. The piston must therefore move upward and downward 33 times every second, and its (maximum) speed in the middle of its stroke is around 45 feet/second. If a fuel burning in the cylinder is to actually push down on the piston, in order to do actual work in propelling the vehicle, the fuel-air mixture needs to burn at a speed FASTER than the piston is moving! Otherwise, the slow-burning mixture would actually act to SLOW DOWN the piston! It would not only not do productive work, but it would require work FROM the piston.
The ACTUAL flame-front speed inside an ICE might be sufficient for conventional burning as in current ICE engines, but someone needs to do the experiments to confirm that! But it suggests that yet another hurdle might lie in front of Hydrogen ever becoming a common motor fuel.
By the way, the INTENDED usage of Hydrogen in vehicles is quite different from this! The much-publicized Fuel Cell is a device which converts the energy in a fuel like Hydrogen DIRECTLY INTO ELECTRICITY. The premise for future vehicles is that they might use Fuel Cells to provide electricity for electric motor drive systems. Which means that Mortuary Services will soon be appropriate for the Internal Combustion Engine! But it may be another ten or twenty years before fuel-cell technology has developed to the point of that becoming realistic.
As an additional note here, when you see impressive demos on TV or in a video regarding Hydrogen being used as a fuel for a vehicle, try to check to see the source of that Hydrogen! In general, such demos use LIQUID Hydrogen (which is necessarily refrigerated to incredibly cold temperature, within a few degrees of Absolute Zero!) LIQUID Hydrogen does not have the problem of the huge volume of Hydrogen as a gas (where one pound takes up around 200 cubic feet) (one pound of liquid hydrogen takes up less than 1/4 cubic foot, almost 1,000 times smaller). Where we have discussed that one cubic foot of Hydrogen gas only contains around 360 Btus of chemical energy, one cubic foot of Liquid Hydrogen contains around 300,000 Btus of chemical energy in it, relatively comparable to the energy concentration of gasoline (about half of it). So, for demonstration purposes, a fairly small amount of LIQUID Hydrogen contains spectacular amounts of energy in it! Which then gives impressive performance by the demo vehicle. However, IF they used LIQUID Hydrogen, that (small) amount for the demo quite possibly cost them tens of thousands of dollars to buy!
There IS a reason that NASA uses LIQUID HYDROGEN as the fuel for nearly all their liquid-fuel space rockets. But they also are very aware of the bad memories when such rockets have blown up in the launch pad! And then there was the Hindenburg disaster in the 1930s that ended the popularity of Dirigibles. NASA never admits the enormous cost involved in producing and refrigerating that massive amount of hydrogen for a launch! Check it out! It is a spectacular expense!
OK. Finally, there are all kinds of hucksters who are trying to sell all manner of products that they claim will give you tremendous improvements in the gas mileage of your vehicle by somehow injecting Hydrogen into the engine. This is really sad regarding how deceptive their presentations are. Again, if you would inject LIQUID hydrogen into any engine, you COULD add a large amount of additional CHEMICAL ENERGY into the engine to be burned. However, what they try to sell are tiny devices which they claim are hydrogen generators. You should realize from this presentation that even if you could generate one cubic foot of hydrogen each minute (which is extremely difficult to do AND would require many horsepower from the engine to generate the needed electricity to do it), that would only be adding around 360 Btus of chemical energy in the hydrogen into the engine (where a gallon of gasoline contains 126,000 Btus of chemical energy in it). A demo where LIQUID hydrogen was injected COULD show measurable improvement, but any device that tries to generate GASEOUS hydrogen to be injected is simply an expensive joke!
It seems that the wild enthusiasm that Ethanol was going to be "the total energy solution for the future" has faded. And I think that people are starting to realize that Fuel Cells that would be affordable and practical for vehicle propulsion are probably still 50 or more years in the future. And battery power had a brief public excitement recently, as it had earlier done during the 1980s. Tower windmills are starting to be seen as only around 1/10 the devices they were promoted as being. So the "breakthrough of the month" lately is algae. As with all the others, it is pretty easy to set up an impressive demo of a few minutes' usage for a few reporters, which gets the public excited about the latest fad energy supply. But like all the others, algae has some major obstacles to overcome. And like all the others, the biggest of the obstacles is the SCALE of our needs.
Yes, with a few million dollars of equipment, it IS possible to grow algae and then extract either hydrogen gas or power directly. But the unspoken detail is that the amounts of equipment which would actually be needed would be comparable with the surface area of the Earth! Do you know how large an acre is? Imagine growing algae in ponds all year, where greenhouse heating will be needed much of the year. But that acre receives around 22,000 kiloWatt-hours of sunlight on a nice sunny day. But the algae, like virtually all other plants, can only absorb certain colors of that incoming sunlight and there are many other losses, where the overall conversion efficiency is generally only around 1%. That means that the full acre of algae farming will only capture about 220 kWh per day as glucose.
The known chemical processes to extract hydrogen from that are generally no better than around 50% efficient, so at best, we could hope to capture around 110 kWh of energy per sunny day per acre. In comparison, one gallon of gasoline contains around 37 kWh of energy in it. So all the equipment and that full acre of algae farming, at best, might someday be able to produce energy comparable to about three gallons of gasoline! The people doing the demos today are merely getting the public excited so that the government will fund billions of dollars into their hands for future research, which will guarantee their personal employment and prosperity.
No one ever seems to be in a position to cast an analytical eye upon such things! Whenever some spokesperson announces that they have found the ultimate solution to all energy crises, everyone seems to immediately accept all claims made, without reservation! Wow! The brief and crude calculations just presented suggest the BEST production from that acre of algae. On days that were overcast or during winter when heating power was required to preserve the algae from cold, far less can be expected. However, clearly, no spokesperson is going to admit that the FUTURE CAPABILITY may be three gallons equivalent of gasoline per acre of algae per sunny day! Even if gasoline rises to a thousand dollars per gallon, it would have to be cheaper than energy from such an algae farm.
Yes, there will be many claims of breakthroughs, each of which will guarantee funding for some new business venture! And there will be spectacular claims made all the time. But isn't the proof in the pudding? Not in any prior claims about how perfect the pudding will be? And the sad part is that there really is no free lunch available. Everyone WANTS TO BELIEVE that some magical source of massive amounts of energy will allow all people to continue to be as wasteful as we Americans have learned to be for decades. The fact that the public has so little understanding of such matters makes it very easy for some slippery person to deceive a lot of people. If you are very familiar with Hydrogen then you probably have heard of Brown's Gas. A guy who had never had any science education, and not much education at all, declared himself to have a Doctorate Degree, around 30 years ago, and he started telling people that he had discovered the ultimate energy solution, which he called Brown's Gas (after himself). He claimed that his gas was a combination of Hydrogen gas and Oxygen gas, together! His claims were so convincing that he got many people to give him large amounts of money. As a result, he was convicted of cheating people many times and would up spending most of his life in various prisons! But even though his claims were immediately known as false, and all his convictions, there are STILL people today actively promoting that silly concept! I am sure that the web-sites trick a lot of people into sending money in, so I guess it accomplishes their goal of getting rich! It's just that the concept has no value whatever, and it is simply a scam to cheat people.
So, even ignoring the problems discussed above regarding having to compress the Hydrogen to actually be able to use it, we now have somehow created maybe 100 cubic feet of Hydrogen. (That is a volume of five feet by five feet by four feet.) We noted above that each cubic foot contains 319 Btu of chemical energy. So we have 31,900 Btu of energy available. Maybe that sounds good, but your house furnace probably uses up 125,000 Btu/hr in the winter, so that amount of Hydrogen gas would only provide heat for a single house for around 15 minutes! But if we look at the energy consumption of the whole United States, each year, it is a little over 100,000,000,000,000,000 Btu.
Our energy amount above (the 100 cubic feet of Hydrogen gas) is equivalent to around 31 cubic feet of natural gas (at a little over 1,000 Btu/cubic foot). But each year, the US consumes around 30,000,000,000,000 cubic feet of natural gas!
See the problem? Even if the Hydrogen technology could be scaled up by a factor of a MILLION (extremely hard to do!), it would then still only represent one one-millionth of our gaseous energy needs! (We have another web-page in this Domain that presents government and industry data on energy supplies and consumption rates, and it shows that, without imports, the US would completely run out of natural gas in a little over EIGHT years!) So that NEED for a gaseous fuel will certainly exist. But it is hard to see how Hydrogen could provide but the tiniest amount of that need.
Yes, I realize that the public and politicians seem fascinated with Hydrogen as the "answer to all the energy problems", but it is really hard to see how that could realistically happen. We humans have gotten spoiled by being able to consume and waste unbelievable amounts of coal, oil, natural gas and uranium. There seems to be no care at all regarding what people of 20 years from now will do! Some people say that "science will find solutions" but I ask that you note that I AM a Nuclear Physicist! If the US is not able to rely on friendly countries for Uranium, oil, and natural gas, we may all wind up in a Medieval United States! We already used essentially all the Uranium that was under the US, nearly all the oil (4.3 years supply left), and nearly all the natural gas (8+ years supply left). This is bad. Very, very bad. But I truly doubt that Hydrogen can provide any significant alternate source, mostly because our total energy consumption has been so amazingly high!
Another politically popular "energy solution", wind-generating of electricity, has many problems of its own, primarily transporting the electricity hundreds or thousands of miles, because very little actually gets to the end of those very long lines! Even with impressive government funding of wind-generation, it seems very unlikely that such systems can realistically provide more than the tiniest part of the US electricity usage. But it seems likely that politicians will go crazy and authorize a thousand times as many windmills than already exist. And the windmills will soon after be discovered to cause weather changes in the climate, because so much wind is slowed down such that normal weather patterns cannot occur.
The amount of power in wind energy seems impressive during hurricanes and tornadoes, true. But in NORMAL winds, which tend to average around 10 or 11 mph in many areas, the actual amount of electricity which can be produced from wind is not remotely comparable to our amazing consumption of electricity and other energy. Yes, when demonstration projects build hundreds of giant wind turbines (for billions of taxpayer or investor dollars!), it CAN be shown to (sometimes, when the winds blow) produce the electricity needed by some SMALL local town. And everyone celebrates as though they have found magical solutions! But they haven't! If we were in 1890, where there was extremely minimal usage of electricity, yes, those wind farms would be great! But our current usage of electricity is so many millions of times larger than what such tower windmills could provide, it turns out to just be a "wonderful idea" which will not pan out as needed.
So the rather casual comments that "our technology will find ecologically sound ways to make electricity in the future" as the future source of the power to drive Hydrogen generation, is pretty close to Easter Bunny and Santa Claus sort of stuff.
It is really hard to see how the US will be anything other than a total-coal powered country within a few decades. We DO have a lot of coal!
Yes, Hydrogen can be demonstrated in experimental vehicles, and they can have impressive acceleration and speed. But that's with a rather small (BOUGHT!) Hydrogen tank aboard. If you ever see an impressive demonstration like that of a Hydrogen-powered vehicle, make sure to ask how long that vehicle could continue to perform like that. The answer is certain to be no more than a few minutes at most. So, as a demonstration, Hydrogen can seem quite impressive, because it is! But in actual practical applications, the details probably make it never to be usable in our vehicles.
In other words, one of the resulting products is the carbon dioxide that is blamed for much of global warming. But that is really NOT a fault IF the methane is PRODUCED as on a farm, as in that case both the production and oxidation of the methane is part of the natural Carbon Cycle. It is ONLY if the methane being burned had been brought up from being stored underground for millions of years. In THAT case, when it is burned, it releases NEW carbon dioxide into the atmosphere that had been removed millions of years ago.
It sure seems to me that methane is a FAR more attractive possibility regarding solving future energy needs than Hydrogen has any chance of accomplishing.
One downside to Methane / Natural Gas: As glowing a potential solution as it might be, we in the US already use up amazing amounts of it! In fact, government and industry official published documents from 2002 show that we were already having to IMPORT enormous amounts of (compressed) natural gas just to provide what we were already using up! For any possible future based on a "Methane economy", it would be necessary to STOP using up methane that had been buried for millions of years as fossil fuel and instead MAKE IT, to end the increase of adding new carbon dioxide to the atmosphere!
By the way, chemically, Methane is CH4. Another immensely popular concept (but an incredibly expensive and foolish idea!) these days is Ethanol (or Ethyl Alcohol or Grain Alcohol) which is C2H5OH. Methane (gas) and Methanol (CH3OH) (liquid) and Ethane (C2H6 (gas) and Ethanol (or wood alcohol) (liquid) are therefore similar chemically, all simple hydrocarbons, where a Hydrogen atom is in an (-ane) is replaced by an Hydroxyl ion in the (-anol). Some uses benefit from a gaseous fuel, while others benefit from a liquid fuel.
(Ethanol requires not only immense amounts of corn to be grown, at the expense of food crops, which has already  caused grocery prices to rise tremendously, but it requires the heating and fermentation processes of a still and some other processes, and then has to be trucked around, together USING UP about as much (fossil fuel) energy that the Ethanol can eventually provide! AT BEST, we are simply WASTING all those millions of acres of corn crops! Interesting, huh?
C Johnson, Theoretical Physicist, Physics Degree from Univ of Chicago