NationStates Jolt Archive

Why Hydrogen Fuel Cells Are Lousy Tank Engines

Whenever I see a tank using a hydrogen fuel cell engine, I begin to twitch. They are the devil, and I hate them.

It’s not so much the technology I hate as the misconceptions about it. Fuel cells are very useful things… for hospitals and hotels and houses, but not for tanks.

Hydrogen
Making hydrogen
Hydrogen is a fuel that, per unit mass, releases a LOT of energy when combusted with oxygen into water. About three times more energy dense than gasoline, by mass, in fact. It is, however, a terrible fuel, and hard to make.

But wait, I here you cry. You just said that hydrogen and oxygen can be combined to make water. According to what I learned in chemistry, that means it works the other way, and it would only take the same amount of energy as it took to make the water because, according to thermodynamics, energy/mass can not be created or destroyed, just turned into another form.

You are right. However, some energy is lost as waste heat in all reactions. Taking water, removing the hydrogen, and then burning the hydrogen, and so on takes a LOT of energy, electrolysis is terribly inefficient. A far better way is to take gasoline and strip off the hydrogen. That takes way less energy... but you need the gasoline.

Transporting the Hydrogen

Ok, so assuming you understand that, have devoted a nuclear power plant or two to making hydrogen, you still have a problem. How do you store it? Although hydrogen has an amazing energy density by mass (about 40000 joules per kilo as compared to the next best one, propane with only about 14000 joules per kilo, or gasoline with 13500 joules per kilo) it has an absolutely abysmal energy density by volume. At standard atmospheric pressure, it would take more than 3000 liters of H2 gas to equal the energy of one liter of gasoline. If you pressurize it to 150 bar, the safest maximum for pressurized containers (firefighters refuse to go higher with their compressed air tanks because of the dangers of explosions) it would still take about 22 times the amount of H2 as Gasoline. Not to mention that another term for any pressurized container at 150 bar is 'bomb,' ignoring the fact that it's filled with explosive gas too. Using modern technology, it is possible to pressurize the hydrogen to over 700 bar… this is fine for cars… but this fuel tank is attached to an AFV. A vehicle that has lots of sharp bits of metal flying at it. If the tank gets perforated by a hot bit of metal, it will explode, and violently, likely taking the AFV with it.

Liquefied hydrogen is still three times bulkier than Gas, and it needs to be super cooled, which takes energy and would drastically increase the IR signature of the vehicle.

An interesting note: there is more hydrogen in a liter of gasoline than there is in a liter of STP H2.

Fuel Cells

This is how a fuel cell works... It takes hydrogen, and combines it with oxygen to make water and energy. But it performs this reaction very efficiently. I hate fuel cell technology, and I will explain why.

It's not so much the tech that I hate as the misunderstandings. Fuel cells don't run on nothing, and they don't run on water either. They run on hydrogen. 'But wait' I hear you cry. "I've got you there. There's hydrogen in water' This is very true. But since water is the exhaust, a fuel cell can't run on it any more than a car can run on CO2. To see why, check out the Hydrogen section above.

Why are they efficient? Because there are no moving parts. This means that more of the energy being produced is converted into electricity and heat. A friend of mine is currently working on a fuelcell at a lab. It’s a fuel cell that burns methane at 800c, and it works pretty well. It's still too big to fit in a car. But the best thing about fuel cells is that they rarely break. The one my friend is helping make is rated for 20 years... how many gas generators last that long? Thait's why fuel cells are good. In industrial applications, they are wonderful. But no tank, or car, will ever last that long, so it's a waste to use a fuel cell on it. The suspension, motors, turret mounting, and everything else in the vehicle will give out decades before the fuel cell does… and the fuel cell being used will be obsolete in five years.

Now, not only are they a wasted on tanks, but they aren’t as efficient as people think. A great deal of the energy produced by fuel cells is heat… high grade, useable heat, but still, heat. Heat, in building, is good, because you can pump it into rooms and make people in offices happy. Heat in a car is ok. Heat in a tank, is bad. It’s unusable energy, and increases the IR signature of the vehicle.

But lets assume that it’s all electricity, and that the fuel cells are operating at the theoretical maximum efficiency of 80% (it physically can NOT go higher, and this efficiency has yet to be reached in labs). Even with that efficiency, it’s still only twice as efficient as a good turbine or ICE… which means you need half the fuel. Given how much heavier hydrogen tanks are, the tendency of hydrogen to ’rot’ metal containers, and the need for a large number of large electrical motors to drive the wheels, this is a false saving.

Alternatives

I personally prefer hybrid diesel electric engines for my vehicles… they give me a nice efficiency boost AND higher peak torque than either normal engines or fuel cell powered vehicles. If you simply must use an exotic fuel, check out Biodiesel… I’m not sure if it’s legit (it has all of my pseudoscience antennae quivering but I can’t find anything wrong with it) but if it is, it promises a steady supply of cleanish fuel.

Thank you. I have done simmilar, though less extensive, research on thos damn things and reached the same conclusion.

Excellent!
I'm getting annoyed with people sticking things on tanks that are barely, or not even, out of labs yet, let alone military capable, and calling them modern technology.

I have only one problem with your information, that is use of heat in a tank.
Heat in a tank, is bad. Actually, it's good. Tanks are cramped, and made of metal, which means if you drive them in the cold you're going to freeze your butt off. They do come with heaters, but they don't work too well, espically since they have to heat the air, and when the air heats, it gives that heat to the steel. So heat in a tank is a good thing.
Tanks will always have a high IR signature, it's a part of the job. In fact, gas turbine engines will double, if not tripple, the IR signature of a tank, but when you can get a tank more mobile, this doesn't matter.

We're talking enouigh heat to warm an appartment building. I agree, keeping a tanki at a nice cozy 24 degrees is good, but the most efficient fuel cells run at several hundred degrees C... some at over a thousand. That's a little much.

I'd also assume that modern MBT's would have a good deal of insulation. The turbine exhaust from an Abrams is hot enough to injure infantry nearby, so I'd imagine the inside would get pretty tosty without signifigant protection. Not to mention that NBC protection and enviromental systems would probably take care of the problem.

VA, it's Azazia... now hopefully people will heed this information... although I doubt it... but good work as always...

We're talking enouigh heat to warm an appartment building. I agree, keeping a tanki at a nice cozy 24 degrees is good, but the most efficient fuel cells run at several hundred degrees C... some at over a thousand that's a little much.


All the heat doesn't have to go into the tank to warm it. You said it yourself, you can use a fuelcell heat to warm a car.

urg.... I just reread that post. Choppy and horrible; I really need to get more sleep if I'm writing crap like that.

And thanks, Azazia =) I'm working on a post for the colony RP right now, but given the low quality of my writing currently, I want to re-read it later

All the heat doesn't have to go into the tank to warm it. You said it yourself, you can use a fuelcell heat to warm a car.

Well... yes. THe same way you can use an ICE to warm a car. But the amount of energy it takes to warm a car (or a tank) is infantismal compared to the amount of heat generated, so most of it is wasted in vehicular aplications. In large buildings, where you have a lot of space to heat, it's not wasted.

I have only one problem with your information, that is use of heat in a tank.
Actually, it's good. Tanks are cramped, and made of metal, which means if you drive them in the cold you're going to freeze your butt off. They do come with heaters, but they don't work too well, espically since they have to heat the air, and when the air heats, it gives that heat to the steel. So heat in a tank is a good thing. Tanks will always have a high IR signature, it's a part of the job. In fact, gas turbine engines will double, if not tripple, the IR signature of a tank, but when you can get a tank more mobile, this doesn't matter.

Additional heat is not a "good thing", f e the M1A2 SEP had to refurbish the entire interior and add a lot of cooling equipment to avoid frying its own electronics.

Generally electronics do not like heat, they operate less efficiently and break down faster, incurring greater life-cycle costs for the system.

Also, heat signature is a big deal, especially unless you completely control the airspace. A large heat signature make the vehicle easier to detect and target for enemies equipped with thermal imaging devices, or weapons like Javelin, STRIX (anti-tank mortar round) or BONUS (anti-tank artillery submunition) that use thermal imaging for target ID/tracking.

So to put it shortly, against a qualified and well equipped enemy, heat signature WILL matter. It will matter a great deal.

Think about it like running around at night in a dark forest with a luminescent suit on, do you really think that you won't be at a disadvantage mucking it up with people in BDU's?

Additional heat is not a "good thing", f e the M1A2 SEP had to refurbish the entire interior and add a lot of cooling equipment to avoid frying its own electronics.
Actually, unlike say, every diesel engined tank around, the M1A2 SEP generates alot of heat. And, since it's used mostly in desert conditions, this is bad, so they have to cool it down.

Generally electronics do not like heat, they operate less efficiently and break down faster, incurring greater life-cycle costs for the system.
But humans do not like cold, so if you freeze your crews, no ammount of electronics are going to help you.

Also, heat signature is a big deal, especially unless you completely control the airspace. A large heat signature make the vehicle easier to detect and target for enemies equipped with thermal imaging devices, or weapons like Javelin, STRIX (anti-tank mortar round) or BONUS (anti-tank artillery submunition) that use thermal imaging for target ID/tracking.
Ever stand next to a tank? They're HUGE, they're easy to spot as it is.
The tank is about the worst place to be on the battlefeild, and always has been. Everything is out to kill tanks, and everything can. Even a diesel engined tank made yet (And the ones that use petrol) will give off more then enough heat then any IR missile needs to lock onto a target.
While I can't argue that anti-tank IR guided weapons are a problem, you're forgetting that they're one small bit of alot of problems.

So to put it shortly, against a qualified and well equipped enemy, heat signature WILL matter. It will matter a great deal.
Against a qualified and well equipped enemy, tactics matter.

Think about it like running around at night in a dark forest with a luminescent suit on, do you really think that you won't be at a disadvantage mucking it up with people in BDU's?
Actually, as I've said above, you're virtually doing that if you're in a tank on a battlefeild at all.

A vehicle that has lots of sharp bits of metal flying at it. If the tank gets perforated by a hot bit of metal, it will explode, and violently, likely taking the AFV with it.

Actually since hydrogen is so much lighter than air an exploding hydrogen tank is much safer than an exploding gasoline tank. The hydrogen quickly ignites but that explosion is funneled up into the atmosphere and the damage is contained. A gasoline explosion will, well, explode in every available direction and will burn for as long as it can combust.

You've also overlooked one of the biggest advancements in hydrogen storage-- metal hydrides. While they are still not perfect, they do solve quite of bit of the problems inherient in hydrogen storage. Since the hydrogen stored in the hydrides is nonexplosive it is much safer. Several different metal storage products even show that the storage medium, when "filled" with hydrogen would be so safe that it could be used as a construction material in consumer vehicles.

...
Hooray for jet turbines!
I never really bothered thinking about my tanks engines, I just made up some crap about antimatter reactions doing stuff.
Hooray for futuretech!

And I suppose another slight problem with hydrogen (and just about any fuel) is that it tends to explode. Gasoline/diesle doesnt always go 'Boom!', if your lucky it just burns. As far as I know, if you hold a flame to hydrogen it goes 'boom' no matter what, this might be a bad thing in a tank packed with high explosives already.
Perhaps we should all convert to hand-cranked tanks :)

Actually, unlike say, every diesel engined tank around, the M1A2 SEP generates alot of heat. And, since it's used mostly in desert conditions, this is bad, so they have to cool it down.

Tanks have a hard time getting rid of excess heat when running regardless of propulsion type (much because they need to be compact in design), the turbine system just taking this a bit further than any other type of combustion engine in service today.

So no, diesel engined tanks do suffer as well, just not as badly as the relatively extreme temperatures created by the gas turbine (wbetter than is not necessarily good).

From this POV the diesel is better, granted. BUT;

But humans do not like cold, so if you freeze your crews, no ammount of electronics are going to help you.

So you think that the best way to keep the crunchies warm is to idle the main engine?

Better have a real good logistics train transporting fuel then...

Me, I'd issue a small heater to warm the crew compartement and provide crew stations with insulation, just as we do in Sweden, but we know nothing about cold weather warfare up here. ;)

Still, to keep a tank in readiness in sub-zero conditions you probably need to idle the engine 15 mins an hour anyway. Not to keep the crew warm, but to prevent the engine from freezing solid and so on... Diesels are really cantankerous when cold anyway (they don't burn the fuel properly and have a tendency to soot up and refuse to fire until the engine is cleaned).

Electronics of today always need "room temperature" for reliability, extreme cold is just death to batteries and capacitators f e.

Tech needs pampering. :p

Ever stand next to a tank? They're HUGE, they're easy to spot as it is.

Ok, so how come NATO, including the USA interdicted the Serb PVO for months in Kosovo without knocking out any significant number of vehicles?

They reported hundreds of destroyed AFV's, but afterwards it proved just over a dozen of the 300 tanks stationed there were hit...

Tanks are big, the world (which you hide your tanks on) is bigger, and its woods are deep. ;)

Heat signature is a very good way to get spotted though. Doppler ground radars such as JSTARS is another, but that is another issue (and can be countered by large scale ECM f e)

The tank is about the worst place to be on the battlefeild, and always has been. Everything is out to kill tanks, and everything can. Even a diesel engined tank made yet (And the ones that use petrol) will give off more then enough heat then any IR missile needs to lock onto a target.

Well, tankers disagree, and I'd say a lot of insurgents in Iraq would too, if they were still alive. Remember that warfare relies on combined arms (and unlike some I will say this was always so, knights needed spearmen and archers, the Roman legions had their auxilia and so on). Tanks, or any other arm cannot and IMHO will not in the forseeable future rule the battlefield alone. Everything need support, and "the worst place to be" always vary with circumstance.

I'd say that the worst job to have during WW2 would probably have been as a Kriegsmarine submariner...

Oh, and btw, so now you accept that signature IS an important issue, just that ou assume or feel that nothing can be done about it?

If a tank is so visible that it is pointless to try and camouflage it on the battlefield anayway, why aren't they just painted pink or dayglo orange? :p

Being less visible is a GOOD thing.

Standing out like Ronald McDonald at a PETA-rally is NOT. ;)

Tanks are big (especially Western-style MBT), but they can succesfully be hidden. There are plenty of rocks on this planet the size of tanks or bigger, if the tank is still and holds ambient skin temperature they will be very hard to detect, as shown by the Serbs.

SAAB already produce a thermal masking net for our Leopard 2S, others paint that also suppress thermal signature. So apparently "people in the know" disagree enough with your POV to invest millions in developing thermal signature suppressants of various types.

F e, IF thermal signature can be suppressed enough that battlefield interdiction aircraft will have a harder time to detect and identify targets, this will wither render them ineffective or force them to approach closer, perhaps close enough that they will be vulnerable to local air defenses, they will at lest take close AD more into account than before, thereby losing effective combat power without you actually having to shoot anything up, all just by masking your gear a little better.

While I can't argue that anti-tank IR guided weapons are a problem, you're forgetting that they're one small bit of alot of problems.

Against a qualified and well equipped enemy, tactics matter.

Tactics always matter regardless of opposition.

Bad tactics can get you killed even if there is NO opposition (people have had a tendency to call down artillery on themselves for decades f e)...

Tactics is however dependant of capability, and needs to be in balance with that. If you shine like a christmas tree, this is a disadvantage. If you don't you will have an easier time both developing and applying successful tactics of your own.

Own capability relative to enemy capability decides wich tactics will be succesful, thats why the oxymoron Army intelligence was invented. ;)

The worse capability you have relative to your enemy the harder it will be to develop and apply a succseful tactic. If your enemy comes with a wing off B2 Spirits carrying nukes and all you have is a wooden club, you better be bloody brilliant as well as your opponent hugely idiotic to pull a victory off, right?

Actually, as I've said above, you're virtually doing that if you're in a tank on a battlefeild at all.

And I disagree. Mechanized warfare isn't very "subtle" in appearance, but you overestimate detection capabilites, especially when opposing a capable enemy. There is a lot of space to cover, and if you can lessen your signature it will be to your advantage.

See for example how the Iraqis were bumrushed by deception in ODS due to cloak and dagger games (an entire armoured corps moved under cover of SigInt deception), also attacks were through an area of desert the Iraqis thought impassable.

Being visible and keeping your heat signature IS important. AFV's are usually said to balance three properties; Firepower; Mobility and Protection.

Concealment (and deception) IS a part of protection.

Finally, someone that agrees that hydrogen isn't a great fuel for a tank. Every time I hear those together I imagine a T-54 burning like the Hindenberg and some reporter yelling, "Oh, the humanity!" Thank you for making this point more obvious.

actually, the biggest problem the crews of AFVs deal with isn't cold, but excessive heat. Crew exhaustion rates for AFVs without air conditioning are much higher than for crews that have air conditioning (as learned by experience in the various Arab Israeli Wars, the various Iraqi Wars and the Soviets found as well in Afghanistan).

Which is why most Western AFVs since the 1940s have had it. It also allows for the creation of overpressure, to keep out hostile gases, chemicals, biological agents and radioactive fallout.

The few months a year when cold is a real issue just isn't as big a problem because most combat operations take place during the warm months, the Russian Front in World War 2 being the only really significant exception.

There the problem wasn't crew habitability so much as keeping the oil from freezing so that the various mechanical parts would operate successfully, as well as battery life and maintaining the monsters while working outside when the metal could injure you if you touched it without gloves.

Regardless of the principal use of diesal and turbine engines for tanks today, long term they are going to convert to hydrogen power at some point. Simply because the price and quantity of oil will make it a necessity, and because once the technology matures, it will be as reliable as internal combustion power..... a few decades off probably, but perhaps sooner.

Remember what World War 1 tanks were like, primitive underpowered engines with very uncomfortable conditions for the crews. Then compare those tanks to the PZIV and Sherman and T34, and the current T90 and M1A3

A similar process will occur with hydrogen powered vehicles. Perhaps at a faster rate too

as far as thermal signatures and hiding the monsters goes... the US Army has routinely used decoys for years, the Serbs and Iraqis did so with a lot of success and decoys are standard for combat formations today.

The bottom line is that if you are spotted on a modern battlefield, and the enemy has something to hit you with, they will. And most likely destroy the target.

Its very hard to spot a tank while moving at several hundred KPH at several thousand feet. In spite of US Air Force claims, postwar in both Serbia and in the First Gulf War, it turned out that the bombers hit half to a tenth of what they claimed. Even with laser guided smart bombs. Most of the combat vehicles killed in both Gulf Wars where destroyed by helicopter gunships, AFVs and artillery, during a fire fight. (the thermal signature of a gunflash is huge compared to that of a motionless vehicle which is a partial explanation of that).

So hiding is a good thing.

Tactics is even more important. Combined arms tactics always have an edge against opponents not able to coordinate effectively. The Israelis learned that the hard way in 1973 when their tanks charged Egyptian infantry without their own infantry and artillery support and got slaughtered by anti tank missiles. Ever since then, combined arms have been very strongly emphasized, for good reason.

A better trained opponent will usually beat a lesser trained opponent unless numbers or technology is massively against them. The Isrealis are the example here, but so was the US Army in both Gulf Wars. The First Gulf War saw a relatively even number of Western Troops destroy the Iraqi Army in days without suffering significant losses. The Second Iraqi war saw the same thing but this time the US was even more outnumbered (although it was helpfull that a lot of the Iraqi Army quit before the fighting really got started).

Actually since hydrogen is so much lighter than air an exploding hydrogen tank is much safer than an exploding gasoline tank. The hydrogen quickly ignites but that explosion is funneled up into the atmosphere and the damage is contained. A gasoline explosion will, well, explode in every available direction and will burn for as long as it can combust.

You've also overlooked one of the biggest advancements in hydrogen storage-- metal hydrides. While they are still not perfect, they do solve quite of bit of the problems inherient in hydrogen storage. Since the hydrogen stored in the hydrides is nonexplosive it is much safer. Several different metal storage products even show that the storage medium, when "filled" with hydrogen would be so safe that it could be used as a construction material in consumer vehicles.

H-shire, I wasn't refering to the combusting gas, I was refering to the tank ripping itself appart. I agree, hydrogen isn't particularly dangerous to work with and the fires are much less nasty than hydrocarbon fires (thoughthe fact that the flames are invisible is a bit of a problem for firefighters), but the pressurized gas tank alone is a terrible danger.

As for hydrides, I deliberately left them out. For the most part, researchers are leaving those be, because the energycost of reforming the hydrogen, the increased mass of the fuel, and the mass cost of the reformers make it a less than optimal solution, especially with the new high pressure fuel tanks.

Dostanuot Loj: I have to disagree with you. Tanks are still queen of the battlefield, when properly supported by infantry. They are hard to kill, are invulnerable to a wide range of weapons, are highly mobile, and pack a heavy punch. This doesn't mean they are invincible, they need infantry protection and air cover to operate effectively, but they are still the best offencive and defencive system around.

New Shiron: I disagree that the switch to hydrogen is inevitable. It is very hard to refine hydrogen, you either need to use electrolysis or strip it off a hydrocarbon... and if you're doing that, you may as well simply burn the hydrocarbon. Sure you increase emissions... but tanks aren't the most enviromentally friendly vehicles at the best of times.

its also very expensive and technically difficult to make gasoline, jet fuel and diesel, but a way was found.....

hydrocarbons, particularly oil, are more value as material resources than as fuel... so eventually the change will occur.

Even better will be fusion power or small fission reactors (like the kind the Russians use for their ocean survellience sats), buts thats a while off too, and even more expensive.

Based on current tech you are right, but in a few years, I suspect things will change dramatically.

its also very expensive and technically difficult to make gasoline, jet fuel and diesel, but a way was found.....

hydrocarbons, particularly oil, are more value as material resources than as fuel... so eventually the change will occur.

Even better will be fusion power or small fission reactors (like the kind the Russians use for their ocean survellience sats), buts thats a while off too, and even more expensive.

Based on current tech you are right, but in a few years, I suspect things will change dramatically.

No... currently they're more valuable as fuel. That's why they're still used as fuel. The moment they become more valuable as material resources, you can bet gasoline prices will skyrocket.

The only way, other than the reformation of hydrocarbons (which you claim are too valuable to use as fuel) is by getting it from water. But water is ASH, it makes as much sence as trying to make gasoline from CO2 and water.

No... currently they're more valuable as fuel. That's why they're still used as fuel. The moment they become more valuable as material resources, you can bet gasoline prices will skyrocket.

The only way, other than the reformation of hydrocarbons (which you claim are too valuable to use as fuel) is by getting it from water. But water is ASH, it makes as much sence as trying to make gasoline from CO2 and water.

hydrocarbons are used as fuel simply because at this point we do not yet have a reliable cost effective alternative.... and the price is already going up (heavy sigh as I look at the price of the gas station pumps across the street, already 10 cents more expensive than yesterday)

technology changes though.

You are right, as of now, there is no useful way to use fuel cells in military vehicles. My contention is that within a couple of decades that will change. Or a more effective alternative using hydrogen will be found.

My contention is that within a couple of decades that will change. Or a more effective alternative using hydrogen will be found.

THAT I can agree with.

I believe that is true as well, and as a fact, there are hydrogen engine being planned for automobiles, such as in California, which Arnold plans to support if a good hydrogen car comes out. My nation, if anything, is just slightly ahead of modern days, due to size, economy, and experience on NS(since December 2002, ressurected, of course). I use these reasons to justify the possibility of an effecient hydrogen engine. However, thanks to your research, I'll just go onto a new form a fuel, now realizing the difficulty in creating such an engine. Instead, I would actually suggested a Hybrid Ethanol engine, since Ethanol actually comes from corn and is a good, effecient burning fuel.

Eh, I went to the hydrogen fuel cell car demonstration for Honda and they explained it in a completely different way. In fact, the creation of the fuel takes mere hours and the mechanism that does this wasn't a nuclear reactor with a uranium core, it was a concealed building about sixty feet long and about twenty feet wide....


Also, the hydrogen fuel cells which have been developed by Honda don't run on hydrongen!. Nothing more, nothing less! They run on something which is much like natural gas which is created through a process which in run inside that building I told you about - I can't find the pamphlet which explains the process, but I will get it up here A.S.A.P.



But lets assume that it’s all electricity, and that the fuel cells are operating at the theoretical maximum efficiency of 80% (it physically can NOT go higher, and this efficiency has yet to be reached in labs). Even with that efficiency, it’s still only twice as efficient as a good turbine or ICE… which means you need half the fuel. Given how much heavier hydrogen tanks are, the tendency of hydrogen to ’rot’ metal containers, and the need for a large number of large electrical motors to drive the wheels, this is a false saving.


I care nothing about how much I save, or how much I lose, or how much it costs...I care that it's quiet and in mass formations is less likely to give numbers away.


However, the notion of giving said propulsion to every mechanized vehicle in your nation is completely dumb. Each of those 'buildings' cost about a million a piece...meaning a large RV type truck would cost about a million for the machine and three hundred thousand or so for the truck, depending on the design of the truck. On a ship it could cost about two million or three...so, having 200,000 military vehicles, including IFVs, MBTs, other tanks and AFVs is not cost effective... again, neither is having some of your tanks (for me about thirty thousand tanks total, my Muwatallis class which are very expensive), but it's much less costly than all of your vehicles...


Again, I'll get that exact process up here once I find it...soon enough!

I believe that is true as well, and as a fact, there are hydrogen engine being planned for automobiles, such as in California, which Arnold plans to support if a good hydrogen car comes out. My nation, if anything, is just slightly ahead of modern days, due to size, economy, and experience on NS(since December 2002, ressurected, of course). I use these reasons to justify the possibility of an effecient hydrogen engine. However, thanks to your research, I'll just go onto a new form a fuel, now realizing the difficulty in creating such an engine. Instead, I would actually suggested a Hybrid Ethanol engine, since Ethanol actually comes from corn and is a good, effecient burning fuel.


Both BMW and Honda use the new hydrogen fuel cell stacks which were designed in late 2004 and which I saw in the demo.

The Macabees, some fuel cells can indeed run on natural gas... however, those fuel cells are the ones that run fairly hot. The heat is needed to give the activation energy for the reaction, since you need to break apart the hydrogen from the carbons before it can run through the fuel cell. Origionally, a reformer was required to do that, but now there are fuel cells that manage it on it's own.

The process was probably simply refining the natural gas and removing all the impurities so only methane remained. As I mentioned, methane burning fuel cells exist. As I also mentioned, they run hot.

Did you check out the power outputs of the Honda vehicles? Did you notice how small and light the cars are? Did you notice the relatively limited range? For small commuter cars that don't need to go on the highway, fuel cells are great. For MBTs that weigh 70 tons and need a range of hundreds of kilometers at high speed while delivering high torque power... not so good.

I care nothing about how much I save, or how much I lose, or how much it costs...I care that it's quiet and in mass formations is less likely to give numbers away.
I was refering to mass savings, not economic.

Frankly, the big advantage fuel cells have is in their long lifespans and low emmissions... the fuel can be provided by large, more efficient power plants than rather crude small ICEs. But when it comes to warfare, power, mass, and bulk are what really matter.

I believe that is true as well, and as a fact, there are hydrogen engine being planned for automobiles, such as in California, which Arnold plans to support if a good hydrogen car comes out. My nation, if anything, is just slightly ahead of modern days, due to size, economy, and experience on NS(since December 2002, ressurected, of course). I use these reasons to justify the possibility of an effecient hydrogen engine. However, thanks to your research, I'll just go onto a new form a fuel, now realizing the difficulty in creating such an engine. Instead, I would actually suggested a Hybrid Ethanol engine, since Ethanol actually comes from corn and is a good, effecient burning fuel.
Ethanol is actually worse than hydrogen, as it has inferior energy dencities by mass AND volume than gasloline, is incompressable, and actually takes more energy to refine from corn than you get out of it.

http://www.unisci.com/stories/20013/0813012.htm

The Macabees, some fuel cells can indeed run on natural gas... however, those fuel cells are the ones that run fairly hot. The heat is needed to give the activation energy for the reaction, since you need to break apart the hydrogen from the carbons before it can run through the fuel cell. Origionally, a reformer was required to do that, but now there are fuel cells that manage it on it's own.

The process was probably simply refining the natural gas and removing all the impurities so only methane remained. As I mentioned, methane burning fuel cells exist. As I also mentioned, they run hot.

Did you check out the power outputs of the Honda vehicles? Did you notice how small and light the cars are? Did you notice the relatively limited range? For small commuter cars that don't need to go on the highway, fuel cells are great. For MBTs that weigh 70 tons and need a range of hundreds of kilometers at high speed while delivering high torque power... not so good.


The Honda had a single fuel cell stack, and that gave the Honda a range of about one hundred and fifty miles, easily just under two hundred kilometers. Meaning, should you put two or three of these inside the larger engines of an MBT it should give your MBT just around two hundred kilometers. Although modern MBTs give you around five hundred kilometers the wars I wage aren't fought over vast expanses, and even then, with my logistical ratio of 7:1, compared to the 2:1, 3:1 or 4:1 of others, should be large enough to supply these tanks without long stops.

As for torque, I'm going to have to run the equations when I get home, or maybe some time in one of my school periods. However, as for what the engineers at Honda told me the torque wouldn't be much of a problem, even for something as large as an MBT.

The Honda had a single fuel cell stack, and that gave the Honda a range of about one hundred and fifty miles, easily just under two hundred kilometers. Meaning, should you put two or three of these inside the larger engines of an MBT it should give your MBT just around two hundred kilometers. Although modern MBTs give you around five hundred kilometers the wars I wage aren't fought over vast expanses, and even then, with my logistical ratio of 7:1, compared to the 2:1, 3:1 or 4:1 of others, should be large enough to supply these tanks without long stops.

As for torque, I'm going to have to run the equations when I get home, or maybe some time in one of my school periods. However, as for what the engineers at Honda told me the torque wouldn't be much of a problem, even for something as large as an MBT.

Er, the fuel cells are the generators, not the fuel tanks. And the honda fuel cell has an output of 86kW. Tanks need more than 1000kW. Which means you'll need about 10 stacks... just to generate the electricity. Then you also need the actual motors to deliver it to the wheels, AND the fuel tanks

The 500km is under optimum operational conditions. I guaruntee you will run through fuel very very quickly. your tanks will spend a great deal of time idling, or sprinting at inefficient speeds, or moving back and forth... and don't boast to ME about your logistical tail=) Just because you do things more realistically than other NSers doesn't mean you are exempt from real problems.

In no way am I exempt from all problems, I'm just less likely than others from experencing cripping logistical problems.

I'll have to talk to a few engineers I know over this fuel cell business. Last time I asked them, at the demo, about the usage of fuel cell technology on main battle tanks about twice the weight of an Abrams they said that four or five should be fine....I'll have to go over it with them...and I need to find that pamphlet as well.

Twice the weight makes it even worse.. and then you need to add in suspension problems, and lack of mobility, collapsing bridges, and all that jazz...

Twice the weight makes it even worse.. and then you need to add in suspension problems, and lack of mobility, collapsing bridges, and all that jazz...

Well, twice the weight was sorta to state an extreme...my MBT is nowhere near twice the weight, and the actual millimeter rating for the armor is much less than the Abrams (the RHA is considerably higher).

OOC: Sorry to go off-topic, but is VA Chardonnay? What incarnation is he in now?

I hope your not talking about me using Hydrogen Fuel-Cell Technology in my Submarine and Ships? In PMT, I use a Hydrogen Fuel-Cell Fighter, and I can explain it if you need me to.

Right now, I am experimentinmg with the Hydrogen Reactor concept inside a Submarine. I would never, however, go so far as to say a TANK can have that fuel-cell technology. I have looked at speeches like yours and know for a FACT that its inefficient and Diesel engines are far better, and thats why I still use gasoline-powered Tanks, or hybrids thereof.

As for the Ships in the MT territory, or PMT, I use Hydrogen Reactors. Sure, you can call it a godmod, but it's not small and it's capable of producing efficint amounts of energy to substain the ship. I currently have these two reactors placed in a Experiemntal Submarine, and an Attack Carrier. If you'd like to see the stats, just ask.

Overall, I agree, until science comes up with a better way to produce energy from hydrogen, its not going to last long. So yea...anyway.

Even better will be fusion power or small fission reactors (like the kind the Russians use for their ocean survellience sats), buts thats a while off too, and even more expensive.
The RTGs in sats are neither fission reactors nor fusion reactors. They simply use the waste-heat produced naturally by the decomposition of radioactive materials. Not sure about the Soviet versions (which also power lighthouses), but the ones used in the Cassini probe were plutonium based, and produce about 300 watts, with the entire RTG weighing in at about 60 kilograms.

Hydrogen fuel stacks have nothing to do with fusion reactors [hydrogen reactors]. In early 2005 I saw the Honda prototype here in Chula Vista and their one million dollar (!) gas station. Hydrogen fuel cell stacks work in which they have an anode [hydrogen] and a cathode [oxygen] on opposite sides, much like a water cell [which is why water is a huge source for the fuel - at least according to the schematics on their fuel conversion processes] - it's not a fusion reaction. The anode would break up into protons and electrons and the electrons would flow towards the perimeter, and so electrons now react with O+, which would normally create water... which is why these cars exhaust spill out vapor. However, torque is absolutely horrible and horsepower not much better. In other words, we're not going to see these on tanks any time soon.

OOC: Sorry to go off-topic, but is VA Chardonnay? What incarnation is he in now?
Well....

Well....

Wouldn't it be better to send a PM to Chardonay via the NS Draftroom board, instead of gravedigging threads that are over a year old?