Asymmetrical Information

I'm not engineering or chemistry, but I want to get a comment in anyway.

That link you posted is gospel. :)

It's not particularly explosive. If it's gas, it just dissipates upward (it's even lighter than helium). But my understanding is that it will probably be stored as metal hydrides in automobiles, which aren't very energy dense, but are also not susceptible to detonation.

Little-known fact--the Hindenburg fire was a hydrogen fire. It was mostly diesel fuel. The hydrogen in the gas bags burned until it was fully released, but it's not what caused the intense heat below. And it didn't explode.

Neither did the Space Shuttle Challenger, for that matter. I blogged about that on Tuesday in honor of the seventeenth anniversary.

Of course, this all ignores the real issue, which is that hydrogen is not an energy source--it's an energy storage mechanism. It's currently produced from fossil fuels, and switching to hydrogen cars doesn't eliminate pollution--it just moves it from where the car is located to where the hydrogen is actually being produced.

And BTW, I think I'm a day late, but happy birthday, Jane.

Doh!

I just noticed an error in my first comment. That should be "...the Hindenburg wasn't a hydrogen fire."

Doh! squared...

I should have gone to read the link before commenting--I see that I just repeated most of what it said. It does get the Shuttle thing wrong, though, in calling it an "explosion" at all. There was no explosion, in the technical meaning of the term. As I said, I posted on this a couple days ago.

The article seems accurate as far as I know. A reasonable comparison would be to natural gas, which also is lighter than air (though not as much lighter as H2). The only problems with NG are when it collects (say, in a house) and then is ignited. Presumably a car in an accident would not be able to collect enough H2 to cause problems.

Rand Simberg has already pointed out the main problem with the hydrogen-car argument (ie storage vs source). Another one the article does not address is that we can't yet store H2 at sufficient density to give a vehicle a reasonable range. If we end up needing some sort of super-pressurized tank, that may cause problems of its own.

I thought it a little funny that the article mentioned hydrogen bombs. I've been waiting for someone to bring up that (spurious) connection for years.

Rand's mostly right, but hydrogen doesn't have to be extracted from fossil fuels (although right now, that's the cheapest way). And it doen't have to be combined with metal hydride (ditto). There's currently a lot of work being done with alcohols and other chemicals, which would pollute a lot less.

Rand makes a good point, the are enormous losses in the transfer from electricity to Hydrogen power. The amount of electricity it will take to supply hydrogen to a feet of automobiles the size of the US fleet is staggering. This will rise the stock of coal however. The US has the largest coal reserves in the world with Russia and China a distant 2nd and 3rd. The widespread use of coal to produce will also create a boom in the asthma medicine market.

Hydrogen does burn cleanly -that is the point. At a children's party last week, we had lots of fun electolysing water (I suspect it had Hydrogen Peroxide in too), venting the gas into washing-up liquid in childrens hands so they had lots of H2 bubbles there, then lighting them.
It exploes with a loud crack, but your hand is unharmed.
Hydrogen is not inherently explosive -it needs oxygen to explode, and this limits the explosive force compared to, say, TNT.

Alex, I don't think that there's a net carbon gain from creating hydrogen from alchohol -- the amount of biomass required, and the extreme inefficiency of the distilling process, would more than eat any gains you got out of the hydrogen.

As far as I know, any gains to be gotten from hydrogen will come from the difference between teh ca. 30% theoretical efficiency limit on internal combustion and the 50% theoretical limit on steam turbines, which would drastically extend your miles-per-CO2 by up to, say 3.5 times (considering that internal combustion engines are not currently at or near their theoretical limit as far as I know). On the other hand, a net gain then requires you to get at least 50% efficient conversion from the hydrogen. I have no idea what the actual conversion is, but it suggests that while there could be some gain, it is not going to solve our problems.

Check out the LEL (Lower Explosive Limit) and UEL (Upper Explosive Limit) of hydrogen and compare it to other substances such as LPG, Acetylene, Methane, or gasoline.
Gas UEL LEL
Hydrogen 4% 75%
Acetylene 2.5% 80-85%
Methane 5% 15%
LPG 1.8% 9.5%
Gasoline 1.4% 7.6%

As is apparent, hydrogen has a fairly large range in which it can explode, this is not necessarily a bad thing. For instance theoretically with a little fine tuning (not sure exactly how much) a gasoline powered internal combustion car could be turned into a hydrogen powered internal combustion car, a possible bridge between gas and hydrogen. The other advantage of a fuel cell or hydrogen powered vehicle is that air pollution could be shifted for areas where is lingers (i.e. L.A. or Denver) to areas where it doesn't. Finally, if a safe nuclear power plant that meets public approval, with a breeder program, could be built than the energy needs to produce the hydrogen from water becomes a mote point.

Another factor is that because Fule Celss can reaily be driven in reverse, regenerative braking becomes feasible, which means you don't waste so much of your momentum every time you have to stop at a light.
Since I got a car with a real-time MPG display, I've been experimenting with different driving styles, and empirically the difference between the classic accelerate and brake driving style and coasting into stopped lights without pressing either pedal makes a difference between 22 & 28 MPG on the same journey.
Regenerative braking should make this even more true.

Yes Hydrogen is explosive, but so what.

Gasoline is explosive. We've managed to live with the risks present with carrying 20 gallons on the stuff in each of our cars for 100 years of modern motor car production. Designs were updated each design cycle ( every year) and while it was somewhat more common 100 years ago, today you hardly ever see a car, tanker or gas station explode. This despite cars being driven by bipedal simians of a somewhat questional intelligence level ( exhibit A - the pontiac aztec)

If our cars were powered today on 'interstellar ether' you can imagine the looks youd get if you said " hey, this black bubbling ooze from the ground makes a pretty potent fuel, lets use it instead"

My guess the same will be true of the fuel cell cars. The first models will be somewhat deficient, and once they have been hammered on the anvil of real life experience , the designs will be improved.

Just remember - "the perfect is the enemy of the good". Every option has risks, fuel cell cars powered by hydrogen are just another option.

But the real question to you dear "jane": Do hydrogen fuel cells make economic sense?

Sure. . . if they cost less than gasoline car. ;-)

It depends on the overall, rather than the positional, carbon efficiency, a principle that popular advocates for hydrogen power don't seem to be doing a good job of grasping.

I still maintain that in the long run, nuclear power (fission or fusion) for large scale generation and improved battery technology for vehicles is going to be the only long term solution to energy/pollution problems. Of course, if solar power can be made more efficient, if space-based power cells can be used to claim the huge amounts of solar energy that never get near the earth, and if the power from those can be efficiently transmitted back to earth, I'd be thrilled to be proven wrong. Of course, we could pursue both and see which one pans out. Kind of expensive, though, and a lot of "ifs" to deal with.

As Jerry Pournelle is fond of saying: There are no hydrogen wells.

The process of producing useful quantities of hydrogen (leaving aside storage and transport) are all in need of energy production to opoerate. Some shortsighted will say do it with solar power but that has serius efficiency issues and the photovoltaics don't grow on trees. The massive increase in demand for cells would require a big industrial materials input with its own pollution and energy consumption issues.

The real gain here isn't eliminating pollution from cars but instead centralizing it to large hydrogen production facilites that are maintained by a professional crew and thus more likely to run as cleanly as can be achieved. The probability of this is certainly better than sharing the responsibility among tens of millions of car owners and attempting to monitor their compliance.

For an intersting hydrogen risk situation check out Ben Rich's 'Skunk Works' about the great aerospace engineering lab. At one point in the mid 50's they were looking at building a hydrogen burning spy plane. To develop this aircraft they'd need a hydrogen storage facility and so they hired the huy was then the world's only expert on the subject to build it at the lot in burbank. Rich mentions that there was some nervousness about this behemoth. If it lit off it would have the effect of erasing much of Burbank, CA. After some tests it was found to be an extremely small risk that would require a lot of specific condition to get a decent boom even with the massive volume they were handling.

http://www.hq.nasa.gov/office/pao/History/SP-4404/ch8-6.htm

Fortunately the technology for handling hydrogen has come a long way since then.

http://popularmechanics.com/science/aviation/1999/9/skunk_works/index4.phtml

The Hinderburg lit up because they used hydrogen in the blimp. It's flammable.

Actually, Toxic, it's now believed that the Hindenburg lit up because they used a paint of solid rocket fuel (!) to waterproof the canvas shell. Doh!

And as has been pointed out, fuel cells are a battery technology, not a power source. Which is fine, but now we need a cheap scalable power source. Nuclear?

Fuel Cells for generating residential electricity (either off-grid or as emergency backup) exist today, though they are not quite available for retail purchase, but GE and some other folks have working models. Typically, they use natural gas as the fuel source, with a "fuel reformer" converting the NG to hydrogen (with some carbon monoxide as a byproduct, so at least people can still commit suicide in their garage...). They can use propane too.

I suspect the first commercially viable fuel cell cars will use either NG or Propane as the fuel source, since we have production and distribution systems for them already. The neat thing is, the manufacturer can easily design the plant so that the reformer can be disconnected or bypassed, so the same car could be converted to run on pure hydrogen by just putting in a new fuel tank.

That would help sovle the chicken-and-egg problem of developing a hydrogen distribution system. It'll be hard to get commercial investment in a hydrogen network until there are sufficient hydrogen-burning cars on the road to turn a profit, but it will be difficult to get large numbers of those cars on the road until there are convenient places to fill 'er up. Starting with propane or NG systems could jump-start getting to critical mass on the cars.

Once the cars are there, the hydrogen would come along nicely. Car owners would have an incentive to convert to hydrogen only, since it would likely be cheaper per mile.

Actually, the necessary solar cells may inded grow on treesor at least on the surface of ponds.
Algae that can separate hydrogen from water using sunlight as the energy source.

Actually, gasoline isn't explosive either - only gasoline vapor is. If you drop a lit match in a bucket of gas, it'll generally put out the match (but don't try it at home, kids!). The reason you need a carburater or fuel injectors is to vaporize the fuel enough to explode in the cylinder.

Of course, the real problem in an accident (despite what you see in the movies) is not an explosion, but fire (the liquid gas doesn't explode, but it will burn real, real hot..). For that reason, I think the site is right: hydorgen will just escape upward, and not stick around like gas to do some real damage.

Kevin - maybe, but that article only quotes scientists who are working on hydrogen production, and scientists are notorious for thinking that their particular little chunk of discipline is going to save the world. The same words have surely been uttered by hydrate researchers, photovoltaic cell guys, cow-fart catchers, etc.

This article could offer some insight on the issue.

EV World

I know you scientific people are going to probably ahoot me down, but here it goes. As a resident of the great state of NC - I think if you could fiqure out a way to make the H out of a combination of pig $hit and kudzu you could be moving into the Biltmore House. You inputs would be better than free - people would pay you to take it. They are both hydrocarbons, is it just so inefficient that it doesn't make economical sense? Would a negative varible cost offset the inefficiency? Just questions...

Let's talk PR. Since the Hindenburg, have ANY lighter-than-air craft used hydrogen, even though it's much more efficient than helium and safer than hot-air? I don't think so. As long as that film of the Hindenburg's around, hydrogen is a non-starter. Also, how do you get hydrogen fuel cells to emit the throaty roar that adolescent boys get off on? I've got a feeling gas engines are going to be around until I've shuffled off. I guess there's a specific energy problem there. Maybe gasoline is the best it gets. And if the Sildjian (sp?) Ring hypothesis is correct, supplies of hydrocarbons are essentially unlimited. So why do we need hydrogen again?

I think if you could fiqure out a way to make the H out of a combination of pig $hit and kudzu you could be moving into the Biltmore House.

I dunno, John, after you extract some hydrogen, you'd be left with a lot of carbon and nitrogen, probably in really unpleasant form. And I expect there's be a pretty big energy investment just to get that far. Still, there's probably a Federal research grant in it...

My brother was telling me that Perdue has a chicken sh*t problem on Maryland's Eastern Shore. They've used it for fertilizer for so long that the excess nitrides (? nitrogen compounds, anyway) are causing runoff problems in the Chesapeake Bay. So Perdue built a processing plant, and they go around and collect the sh*t from all their suppliers a couple of times a year. The plant turns out fertilizer which is shipped to the Midwest and given away (apparently they don't have a nitride surplus there). Works out to be a good deal for the chicken farmers and the Midwest fertilizer users, but not a money maker for Perdue.

Robert, how is hydrogen safer than hot air?

Also, how do you get hydrogen fuel cells to emit the throaty roar that adolescent boys get off on? Fortunately, modern cars have good sound systems, so adding a throaty roar option won't cost much!

PJ: Mr. Perdue ships NITRATES. Nitrites are potent carcinogens, BTW.

Question: How do you refuel a hydrogen car? Metal hydrides are a non-starter: to liberate the hydrogen you leave behind a sludge of a corrosive material, alkali metal(I) hydroxide. And it takes LOTS of energy to get these back to the hydride.

So how DO you shhove hydrogen gas into a tank? Use higher pressure that is to be contained in the tank. Which means that you have REALLY high pressure hydrogen in the pump system.

Sigh - I wrote about this Fact Of Nature in another part of this blog - you have the inversion temperature problem with pure hydrogen. High pressure hydrogen upon having its pressure released causes the gas to raise its temperature drastically and fast. So it can self-ignite. I saw this happen in Yale Chemistry Department graduate school. A tank of hydrogen under 1500psi cracked a valve. in seconds we had a noisy combustion going, fed by the remaining gas. I didn't see what happened next: I was running down the hall just in case it blew up.

Lots of problems that you can't get around. Anyone ever hear of the Laws of Thermodynamics?

I thought so...

Remember gang, we arent looking at burning hydrogen as a replacement for gasoline, Fuel cells dont work like that.

All of the things that made fuel cells attractive and necessary for the space program will also make them attractive for us.

The fun part is that its the concept of a fuel cell itself that makes the difference here. The are a replacement for batteries. The initail design cuts of fuel cells will likely use easily available Propane. As more people start to use fuel cells in their cars, it will make sense for oil companies to spend the capital necessary to upgrade their stations to include propane. The smart ones will design them in such a way as the facilitate the easy conversion to hydrogen when the time comes.

We will likely see a evolution that goes like this:

1) More people buying hybrid gas/electric cars
2) hybrid cars that use fuel cells using propane
3) cars powered only by fuel cells that use propane
4) standard fuel cell cars using hydrogen.

I think we will get there, but I dont think its a straight line direct from v8 chevys to the nimbus 2000.

(and I'm someone who does believe that as long as the earths core is warm, there will be petroleum.I think its the byproduct of an organic process deep in the earth core, and not the detrius of dinosaurs. )

1) The Hindenburg was painted with aluminum chips and iron oxide. That's not rocket fuel, but it is thermite - a very fine material if you want to start fires, or just want a puddle of molten iron and aluminum oxide melting through whatever is underneath. I don't know what sort of oil or varnish was used to bind them together, that might have been highly flammable too. So, when something set fire to the skin, it spread very fast. That let the hydrogen out and ignited it, but most of it would have risen well above the gasbag before it mixed with enough air to burn. On the other hand, some hydrogen would have met air as soon as it escaped, and it you wouldn't want even 0.1% of all that hydrogen burning close to you. There was also diesel fuel, which might have been dripping on the people escaping downwards, and I think there was plenty of hardwood and fine fabrics in the furnishings of the passenger cabin.

2. The biggest thing that gets left out of most re-tellings of the Hindenburg story - more than half the passengers did escape alive, even though judging by the pictures it must have been over 100 feet in the air when the fire started. I don't know what they were escaping down - but that they got out at all makes me tend to think that at cabin level and below, the fire was no worse than any high-rise fire that isn't damped by sprinklers.

3. But that doesn't tell you much about what happens if the tank on a hydrogen-powered car was cracked. First off, a high-pressure tank of inert gas (N2 for instance) contains quite a lot of energy just from pumping the gas in. It could make a pretty good bomb if it failed catastrophically, and does make a nearly unstoppable rocket if the valve gets broken off. A high-pressure hydrogen tank would be the same thing, plus fire.

I don't know too much about metal-hydride storage, but it sounds like it uses alkali metals that tend to burst into flames on contact with air or water. It's not the safest thing to haul around.

But I don't think that safety is the real problem with hydrogen. Hydrogen cars might require some special safety precautions - make the tank stronger than necessary just to hold the pressure, put a thick layer of foam padding around it, build a valve down in the throat of the tank so breaking off the external fittings would not release the gas - but (as a non-expert) I don't see any insurmountable problems.

The problem is economic. Fuel cells + electric motors are considerably more expensive than the equivalent horsepower in a gasoline engine, and the price is not coming down very fast. There are no hydrogen wells. You have to convert some other form of energy into hydrogen, with appreciable losses. If it comes from fossil fuels or biomass, the hydrogen will cost more per BTU than the fuel it came from, even before you pay the costs of compressing it or forcing it into a metal hydride so it's portable. Solar power at present costs more than fossil fuels, and that's another cost that isn't coming down very fast. Environmentalists won't let us build nuke plants, and if we could build them, we'd be a lot smarter to use the electricity directly than to electrolyze hydrogen.

When fission, fusion, or solar power has reached the point that no fossil fuel is used anywhere you could run an electric line, then we might start looking at ways of turning electricity into fuel, but until then it won't be economic.

Markm nailed the hydrogen storage safety issue: high pressure tanks. We are talking about an upper limit for H2 in liquid form of 35K (70F~~300K; 1K=1deg C) so in order to carry around alot of energy you have to either up the pressure alot or decrease the temperature below 35K. The former is much easier today, but we are talking about 3500 psi tanks, and the average compressed gas K bottle is 150 lbs for a fairly small amount of gas. These vessels have to be designed to resist two drunks running into each other at high speeds. So we are talking big weight penalties, unless we get the H2 really cold, and that is what we do in satellites to provide orbit shuttling fuels for long duration imaging satellites. But I don't think you want to buy into the $40mil/satellite technology for your car.

Frank-

Have you read Thomas Gold's "Deep Hot Biosphere"? He postulates that hydrocarbons were incorporated into the earth at it's formation, and have been welling up ever since...

We're hearing a lot of downsides to hydrogen as vehicle fuel--what's the downside of working on continued improvement in battery technology? The range on current battery powered cars is rather low, but if the recharge time could be cut down, or the range increased to about a thousand miles, that would be plenty for almost all drivers. Why isn't that doable?

Jimbo -

You betcha. I first read about this in scientific america some years ago. I've seen a whole lot more that tells me he's onto something.

( sorry miss galt. I promise not to talk out of turn in class anymore )

To the claim that hydrogen "isn't explosive":

The DC-X single-stage-to-orbit technology-demonstrator vehicle experienced at least one hydrogen explosion/burn (those present insisted it was an explosion), caused by vented hydrogen pooling under the aeroshell and igniting when the engines did.

There was some damage to the aeroshell, and the emergency parachute system was replaced because of heat damage. It wasn't a horrible situation -- the vehicle launched and was performing nominally, but when pieces of the aeroshell started falling off the flight was aborted and DC-X returned to the pad.

Is hydrogen more explosive than gasoline? Almost certainly not. Is it "explosive"? Yes, certainly.

But as others have posted here, the real problems with hydrogen-fueled autos lie elsewhere, and they're enormous.

M. Scott Eiland, regarding better batteries:

Well, just as soon as someone comes up with a major breakthrough in physics, we can start improving battery technology again. We're reaching the theoretical limits of what we understand right now and can't just keep wringing more improvements out of the same stuff.

Actually, some people consider fuel cells the breakthrough in battery technology we need.

M. Scott,

It's those pesky laws of physics again. They always get in the way of our fun.

Battery technology has not stopped by any means. The portable computer market alone is a big driver for research. But packing a lot of juice in a package and doing it safely and economically is another problem.

The first generation of the big car companies push into electric vehicles used lead-acid batteries that were heavy and bulky. And they had some pretty nasty disposal issues down the road, which is one of the reasons many of these vehicles could only be leased and not purchased.

Lithium Ion batteries, as commonly found on laptop computers, have a much better energy density but they're expensive and they also have volatility problems.

Why did Tom Cruise use a PowerBook 5300 in 'Mission Impossible?' THe battery doubled as a grenade.

This is exaggerated. Li-Ion units have a bad habit of causing fires but rarely explode. THe stuff inside can be bad news in easily achieved conditions. The problem with putting them in an EV is you either use a small block of cells to get the same range as earlier EVs at less weight and bulk or you go big and get great range but in a $80,000 equivalent of a VW Bug.

Thus far that's a hard sell.

On car batteries: The Honda EV+'s batteries can store 26.2 kwh, allowing it to go 100-odd miles (Honda says "60 to 120"). I found a chart here listing weight/power ratios for different batteries. Using lead-acid batteries (the cheapest and most mature technology), the Honda's batteries weigh about 750 kg or 1600 lbs. Making them out of (more expensive) NiMH cuts that in half, about 800 lbs; this is what Honda actually used.

By contrast, a gallon of gas has the equivalent of 33 kwh of energy in it. It weighs around 8 lbs (assuming its density is the same as water; actually, I think it's a bit less).

The comparison is a little unfair, because I'm not including the weight of the gas tank, and you need an IC engine to get the energy out of the gasoline, vs a simpler motor in the case of batteries. Still, the contrast in energy density is pretty enormous, and shows how far we need to go. I agree with Other John, we really need a breakthrough before this technology can replace ICE cars.

I think that Stephen Den Beste has covered many of the points that need to be considered before considering jumping to an alternative energy source. Check the URL below, and check with some of the other posts he has on the subject. Good for starting the thinking on some of the ramifications of using other energy sources.

http://denbeste.nu/cd_log_entries/2002/07/Carbonemissions.shtml

There are a couple of big advantages to hydrogen power that haven't been discussed much.

The first is that it decouples the technology for generating power from the technology required to use it. Once you have a hydrogen infrastructure in place, you can start by burning natural gas to provide the power. Then, if a new power source comes along (improved solar or wind, fusion, whatever), you can 'plug it in' to the hydrogen infrastructure and immediately leverage your efficiency gains throughout all the power consumers in the economy.

Today, on the other hand, we have an energy distribution system that is directly linked to the energy technology required. Natural gas for heating, gasoline for cars, etc. This makes our entire energy infrastructure very brittle and difficult to change as technologies improve and fuel costs change. The only exception is electric power, and it shows the strengths of decoupling generation from use. Because now, power companies can move from coal to gas turbines to nuclear, without the consumer even being aware of it, and with no changes to the infrastructure. When cars work the same way, it'll be a great thing.

And electric cars have gotten a bad rap because they were pushed on us before they were ready. Electric motors are a great way to power cars, for several reasons. First, they are pollution free. Second, they are very quiet. Third, unlike internal combustion engines which produce maximum torque at high RPM, electric motors produce maximum torque at 0 RPM. That makes them terrific performers for stop-and-go driving and for sports cars. Fourth, using electric power means you can recover much of the energy used to accelerate by using regenerative braking. And finally, when the vehicle is stopped at a light or in traffic, the motor can be shut down completely so there is no power loss.

Unfortunately, up until now the limitations of battery technology have meant that the electric motors in today's car's are under-powered, which gives electric a stigma of being slow and short range.

But think about this car: A new Lexus sport sedan that does 0-60 in 5.5 seconds, has all-wheel drive with an electric motor on each wheel, dynamic stability by applying power and braking to each wheel as road conditions warrant, has a range of 500 miles, is almost totally silent inside the car, blows hot air through the heater vents almost immediately when the fuel cell starts operating, and has electric power to spare so you can have things like 110v power plugs, instant defrosting of windows, heated seats, steering wheel, etc.

Imagine a contractor's truck that can be driven to a work site, then immediately used as an electric generator to power all the tools on the job.

And since hydrogen distribution will eventually be used to provide power to homes, imagine never having to stop at a gas station again (or rarely, on long trips). You can fuel your own vehicle from your house.

We've been testing fires in cars with various hydrogen tank designs, and while explosions are not likely, the 100-foot torch from a venting tank is fairly spectacular. While a hydrogen-fueled car can be made safe for most accidents, I wouldn't want to be in one that rolled, came to rest on its roof, and then caught fire. Fortunately, in a well-designed system, there shouldn't be fuel around in such a case to start a fire.

Challenges aside, I am a big fan of fuel cell technology, though I do hope we keep a few gasoline refineries around so I can still take my Chevy Chevelle SS out on the occasional Sunday drive.

Anyway, I'd love to get a residential fuel cell system in my house right now - I live in Washington State, and our politicians are no smarter than Californias, so I expect us to have energy shortages on occasion for the next few years and I'd love to insulate myself from that.

And as a reminder - Diesel locomotives are already (have been for 50+ years) electric. The Diesel engines are hooked up to generators which power the electric traction motors, so as long as you have the kWs, you can have quite a bit of power.

I read an article a while ago about a GM prototype getting over 60% total fuel conversion efficiency -- pretty impressive, and far better than the 20-something percent you can get with a gasoline engine.

Of all the alternative energy proposals Bush could have trotted out, this one is about the most realistic.

But yeah, it really is just a energy storage and conversion technology, not an energy source.

The only exception is electric power, and it shows the strengths of decoupling generation from use. Because now, power companies can move from coal to gas turbines to nuclear, without the consumer even being aware of it, and with no changes to the infrastructure.

At a net reduction in efficiency in some cases, such as home heating. e.g. in the case of natural gas you are directly using a fuel that can be consumed with relatively high efficiency at the point of heat requirement. Comparatively with electricity you are burning fossil fuels (usually) to produce electricity, then using the electricity to generate heat. There are other possible examples but this one comes most readily to mind.

IOW for applications that clearly require electric power, such as home appliances, it is usually more efficient for a consumer to buy power from a bulk producer due to economies of scale. But some infrastructure, like natural gas, will not reduce so easily in some cases.

When cars work the same way, it'll be a great thing.

Sure, assuming the current efficiency issues can be resolved. At the moment, the need for batteries puts noteworthy externalities into the production and maintenance of electrics.

And electric cars have gotten a bad rap because they were pushed on us before they were ready.

Thank-you very much, state of California...

Electric motors are a great way to power cars, for several reasons. First, they are pollution free.

No. They just shift the pollution externalities to a different site. The real issue is efficiency -- can an all-electric setup be made more efficient in NET terms vis-a-vis fossil fuel setups?

Second, they are very quiet.

True. This can also be a serious safety liability in urban environments, however.

Third, unlike internal combustion engines which produce maximum torque at high RPM, electric motors produce maximum torque at 0 RPM. That makes them terrific performers for stop-and-go driving

True.

and for sports cars.

No. There is much more to "sports" driving than a quick start. The sound of the engine is one factor. For those who are serious enough to buy a manual transmission, the infinite combinations of play between the clutch, the tire-contact, and varying power output across RPMs ARE a key element of a "sports car." If electric technology ever succeeds in fully displacing gasoline, the meaning of "sports car" will necessarily undergo a huge paradigm shift.

Fourth, using electric power means you can recover much of the energy used to accelerate by using regenerative braking.

Definite advantage, also works on hybrid-electrics.

And finally, when the vehicle is stopped at a light or in traffic, the motor can be shut down completely so there is no power loss.

True.

An implementable hydrogen economy: brief by the Institute for the Analysis of Global Security.

anony-mouse: You're half right when you say that hydrogen cars would only move the pollution to a different site (namely, the hydrogen generating plant).

However, total pollution is likely to be much less, because it's so much easier to clean up one big fixed installation than it is to clean thousands of small, mobile ones.

anonymouse:
At a net reduction in efficiency in some cases, such as home heating. e.g. in the case of natural gas you are directly using a fuel that can be consumed with relatively high efficiency at the point of heat requirement. Comparatively with electricity you are burning fossil fuels (usually) to produce electricity, then using the electricity to generate heat. There are other possible examples but this one comes most readily to mind.

For home heating you can use a heat pump and get back most of that inefficiency. One unit of electrical energy can move several units of thermal energy, making up for the several units of thermal energy it took to generate the unit of electrical energy.

A National Review Guest Editiorial on the subject of hydrogen power turned up this week:
http://www.nationalreview.com/comment/comment-georgia013103.asp

Bill: The heat pump bit was true w/o any discussion of hydrogen at all. But why don't we have scores of residential heat pumps recovering waste heat from our existing NGas fired systems? Because the ROI on such material investments would be slim to negative. The only way you could justify their use with a hydrogen system is under the postulate that the hydrogen would have such a high end user cost that it would make such presently uneconomic investments economic. This does not seem to be a good economic solution despite its engineering possibilities.

A couple of these comments indicate that the writer has never lived in Chicago or Milwakee or Buffalo in the wintertime.

Where's the energy going to come from to heat your car interior when it's -2 degrees? How well does a house heatpump work when the outside temperature drops below 30 degrees? Hint: heatpump furnaces come with auxillary electic heat coils.

Ray:
A couple of these comments indicate that the writer has never lived in Chicago or Milwakee or Buffalo in the wintertime.

Where's the energy going to come from to heat your car interior when it's -2 degrees? How well does a house heatpump work when the outside temperature drops below 30 degrees?

No, I've never lived anyplace colder than New Hampshire in the wintertime. And I've no personal experience with heatpumps. As I understand it groundloop heatpumps work quite well in the winter since the temperature of the ground a few feet under the surface remains ~50 degrees year-round. Whether they are cost-effective for a particular house of course depends on the details -- costs of gas/oil, electricity, installation, insulation, etc. No heating solution will be optimal for everybody.

Off-topic (sorry, but...) - Hindenburg Disaster

The current thinking on this is indeed tht paint was the problem, and it is quite a story. some guy decided to see if he could analyse the movie footage and determine enough from the grey-scale frames to translate it into color footage (no, not Ted Turner). He did pretty well, but noticed that the flames came out orange and red, not the blue of a typical hydrogen fire. Going further, he found the spot near the tail where it had started, then analysed the spread and found it went from panel to panel of the skin, not from hydrogen cell to cell.

Acting on what was now a nagging suspicion, he found (after a lot of trouble) a bit of the surface preserved in a museum and had it analysed by forensic chemists. Adjusting for changes over time, the paint was indeed found to be similar to some solid rocket fuels - but the specific knowledge about that potential was not available when the Hindenburg was built.

During this, he also learned that a new archive of Nazi-era documents had been found which included some of the post-disaster work of the original creator of the paint. The hand-written notes, apparently never completed, showed experiments that demonstrated the flammability of the paint under certain circumstances.

The paint had deliberately been made to be able to conduct electricity, so as to make it safe if hit by lightning while aloft, and worked quite well. But at the time of the disaster, when lightning hit near the tail, lines had already connected the airship to the ground, altering the designed flow. It is suspected that that particular panel may also not have been securely fastened, also affecting the flow.

So that panel caught fire, which was enough to communicate the fire to other panels, and more than hot enough to hole the hydrogen cells.

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BTW, describing it as an explosion is not quite correct, a number of people escaped even though the base of the cabin (the lowest point) was about one hundred feet up when the fire started.

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