Nice (France) - A company called Moteur Developpment International (MDI) has developed an engine that runs very efficiently on compressed air.  Installed in a prototype car, the four-cylinder engine delivers enough power for speeds of 68 mph, with a range of 124 miles.  And the best part, it can be completely refueled from dead-empty in four hours on $2 in electricity.  When it enters production, it will start at about $13,000 dollars.


As most of us are aware today, fuel costs are growing excessive.  This reality has produced one positive side effect, however.  Namely that of the increased interest in alternative power sources.  An inventor named Guy Negre has spent the last 10 years designing a pneumatic engine, one that runs on air.  His vision has now produced a workable air-powered engine which comes in two-, four- or six-cylinder versions which might be practical.

The engine design is called Compressed Air Technology-34, or CAT-34.  It generates no significant heat, only normal heat from changing air pressure.  It runs in a manner consistent with the traditional internal combustion engine, though in a 2-cycle manner.  The power of compressed air drives the pistons rather than tiny explosions of fuel.

Since there is no significant heat generated from the air engine, it does not need a complex cooling system.  This means no large radiator, water pump and no heavy construction.  In fact, 80% of the entire engine is made out of lightweight aluminum, making it weigh approximately half that of comparably powered gasoline engines.  When in full operation, the surface of the engine could be touched without burning.

The air fuel source is stored in three large cylinders made of carbon fiber.  These sit under the car body in the prototype.  They are filled to approximately 300 bar (4,300 psi), which is a typical pressure of SCUBA tanks.  Carbon fiber was chosen for the tanks because if there is ever an accident, the fiber will split open allowing the air to exit very rapidly, but in a controlled manner without shrapnel or dangerous flying debris from something like a metal tank.

The prototype is extremely lightweight, comprised mostly of aluminum.  Still, it is not your family sedan.  Some various prototype designs carry up to four passengers in a tight configuration.  One of them also has a mini pickup-truck appearance with room for hauling in the back.  Still, for a daily commuter the savings in purchase cost and fuel expense may make for a handsome tradeoff.







The CAT-34 engine design also includes one additional benefit, the ability to be regenerative.  When decelerating the prototype, for example, the air engine can be immediately switched from power mode to compressor mode.  It takes the atmospheric air, compresses it and puts it back into the tanks for later use.  This allows much of the braking energy, which is normally lost as heat in internal combustion engine automobiles through the brake pads, to be reclaimed as power.  This gives the engine an additional boost in efficiency for city driving.

Plans are also currently under way to provide a hybrid air/petrol (gasoline) version which will be capable of driving over 3,000 miles on a single tank of petroleum fuel while providing additional speed and power.  That's enough to drive from Los Angeles to New York with one fill up.  Sound impossible?  It is what's being reported.

One other advantage for the daily commuter is that, unlike an internal combustion engine which must be constantly running to provide power, the air engine can come to a complete stop in traffic.  It can begin providing power again without engaging a starter.  Just like an electric car, the engine power is simply available as needed by pressing down on the accelerator, thereby maximizing energy savings in traffic lights, or while sitting in traffic.  Of course, if power accessories like air conditioning are needed, then the engine RPM must be maintained.




While not yet in production, ideas like the air engine are exactly what this world needs.  It will inspire other inventors to come up with the next big "gee whiz, why didn't I think of that?" idea which could truly revolutionize our daily lives.  It seems the free market system might actually work after all, even to solve our energy needs.  Apparently all it needed was just a little air to breathe.

Nice

Oct 09, 2007 10:48     

Excellent article Rick. Gotta love 3000 miles to a fill-up. These would make great cabs and fleet vehicles, think Geek Squad. I don't know about everyone getting em though. People like power, I certainly couldn't deal with a top speed of 68mph.
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Mist engine anyone

Oct 09, 2007 10:54     

when will we have mako reactors? LOL
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RE:Nice

Oct 09, 2007 11:11     

The 68mph top speed is with air only, if I read correctly. With gas it can achieve a lot more.
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Colder Climate

Oct 09, 2007 11:13     

I live in Canada and winter is coming. If the engine produces very little heat, I wonder if the vehical will come with an electic heater. Also, how well can it run in (very) sub-zero temperatures. One more thing, I wonder if they can make a model that doesn't look so dang ugly.
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If you look into any current scuba tank refill comp...

Oct 09, 2007 11:14     

If you look into any current scuba tank refill compressor a small unit is 5HP 40 AMPs Tommays
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I love the technology, but..

Oct 09, 2007 11:16     

It _has_ to be made to look sportier. And how about solar-based compressor to make it perfect?
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of course no heat is produced...

Oct 09, 2007 11:19     

anyone with thermodynamics knowledge will know that expanding gas will remove heat from the surrounding area. So, in fact the engine will run cold - not hot. Partial air-conditioning could be provided to the interior compartment through routing the cold exhaust air to the passemgers. The engine will generate heat on the recharge cycle - just like any air compressor does.
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I want one!!

Oct 09, 2007 11:22     

I want one!! This is perfect for my daily commute (~3 miles). I already bike to work whenever I can but sometimes I'm tired/sick/hungover (j/k) and would like an alternative. I've never drove past 60MPH in my city and unless I get on the freeway I don't need this speed. I wonder how long until it makes it to a dealer nearby. Nice article.
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Rotary Air Engine

Oct 09, 2007 11:34     

I'm slightly more impressed with the rotary style one being developped I believe in Australia. I dont have a name/link off hand, however its primary purpose is for trolleys in a major market place. I believe it uses some of the air to act as a cushion rather than traditional bearings.
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combine with fuel cells?

Oct 09, 2007 11:45     

What if a fuel cell car had this engine? The hydrogen is compressed in tanks already (on some prototypes). This engine could turn a small generator, then the cells oxydize the low pressure gas.
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Hope this becomes reality soon!

Oct 09, 2007 12:22     

This is a fantastic concept. I really hope becomes reality soon. The mileage/size/top speed is still perfect for bay-area driving here in California, also I notice that every morning and evening on average there are only one person in the SUV's etc etc going to and from work! People we don't need BIG cars. Also the compressed air engine also means that you get A/C as a free extra (from gas expanding). All you need to do is get BMW to design the shell and stick a BMW logo on it and put an iPod dock in it and it'll end up being more than popular! Call it the iCar!

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questions

Oct 09, 2007 12:36     

- How powerful is the engine per cylinder (in kilowatts/cylinder) ? - How much energy can be saved in the air tank per unit weight (in mega joules/kilograms for example) ? - How much volume needed for air tank per unit weight (in decimeter^3/kilograms for example) ? Answer of these 3 questions also needed for clear understanding of the new tech's current capabilities. If these parameters are good enough, this technology can be a better alternative to hydrogen powered cars because compressed tanks lose gas in time. Losing hydrogen is much more costly than losing air.

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very cool.

Oct 09, 2007 12:44     

Almost too simple. This is big news, even if it's only mostly accurate. There is nothing wrong with 68 mph.
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compressors are noisy

Oct 09, 2007 12:59     

First I'm skeptical that electricity is so cheap that compressed air tanks can be refilled so cheaply. I don't know how to do that math. To be practical transportation for households these vehicles have to refilled at home. I've worked some with air compressors. They are NOISEY. If everybody had a compressor at home recharging several family cars neighborhoods would be uninhabitable. Can there be very quiet compressors practical for intallation in residences?

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re: of course no heat is produced stuff

Oct 09, 2007 13:17     

There would be heat, because there's moving parts. Friction will cause the motor to heat up, but yes, cold from decompressing would partially negate it. I wonder if you couldn't hybrid this tech with some form of vaporous combustible. You may be able to have a thin mix added to the machine along with the compression. When the pressure is released, you ignite it for a boost. Just at a glance, and with the max speed, it seems that these vehicles are underpowered, hence all the aluminum and small frames. Unfortunately, for the american market, you need to get these things hitting 100 mph and be able to have one model capable of hauling horses... Perhaps when fuel starts hitting 10 dollars a gallon or a vehicle of this type costs 3,000$ dollars or less, you'd start seeing these being produced in mass. There needs to either be a market need or the perception of it being a different class of vehicle. It will not hold up in direct comparison with other cars.

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re: Rotary Air Engine

Oct 09, 2007 13:23     

http://www.engineair.com.au/ Here is the link for the rotary air engine. I think it is cool (no pund intended). I believe both of these air engines were shown on the Beyond Tomorrow show.
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A simple calculation

Oct 09, 2007 14:10     

@deepthought Here is a little calculation which gives the energy that is stored in the tank! I assume the we go from 300Bar to 0Bar which is impossible but this is just an idea about the amount of energy in the tank so it doesn't matter: Per l tank (1/4 gallon for you not SI unit guys) E = P*V = 30e6 Pa * 1e-3 m^3 = 3e5 J ≈ 80 Wh That means if you got a tank on 50 l you have like 0,4 KWh to your disposal. I have not said anything about the amount of loss you will have in such a system. It only gives a maximum limit of the power capacity in the tank.

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Sorry, I don't believe their claims

Oct 09, 2007 14:13     

This is a neat idea. However, I don't believe some of their claims... However great their compressed-air engine is, it still cannot be more than 100% efficient. That is to say, they cannot extract more energy from the compressed air than is put in to compress it. For a start, they state that the car can be recharged in 4 hours, for $2 of electricity. Unless they have aso invented some magical compressor technology, I cannot imagine any compressor that could run for four hours, only using $2 of electricity. Still, interesting technology!

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Good for short/medium commute, run to store but...

Oct 09, 2007 14:14     

...we'll all still need a 'regular old' car or van to make road trips that we all make. You know, the 1-2 hour one way trips to see family or whatever, once or twice a month. Sounds very interesting, though, and perhaps this will be a perfect fit for some sort of hybrid with another alternative technology. Cool.
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RE: comprerrors are noisy

Oct 09, 2007 14:29     

Charlie, If you have a house with air conditioner/heat pump, then you have a compressor on your premises. Most people do not complain about the noise from those, so I doubt you would notice it either. Besides, the typical air compressor used for air tools (impact wrenches, etc) is not even in the same class, generating only 100~200 PSI, while the vehicle's tanks will require air pressurized to several thousand PSI (4300 PSI, per the article). That being said, it is entirely possible that since the "recharge" cycle for these cars is so long (4 hours, according to the article), that they would not have to run at aconsiderably high speed, reducing their noise output.

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The yellow car pictured...

Oct 09, 2007 14:30     

...looks like a Renault Twingo.
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Correction to the calculation

Oct 09, 2007 14:41     

A little correction.. You have 4 KWh in a 50 l tank.. And surely its a nice way to store energy. The same idea of storage energy has come up when in the wind power industry. Just locally to have a big tank to save the energy in.
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Heard about this in June

Oct 09, 2007 14:55     

Back in June they mentioned the use of this technology in PopularMechanics http://www.popularmechanics.co...17016.html @Chris Tann: For some reason the authors have gotten the fuel facts mixed up. $2 is the expected price at gas stations, where refueling can be done in minuttes(as air is allready compressed), and the 4 hour compressor is one that's built into the vehicle so it can be refueled at home using electricity(I doubt as well that home charging will be only $2)

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Forgot the drawback

Oct 09, 2007 15:00     

This is all good news, a cheap air engine and all, however the car has one major flaw. The only way it can be practical is to make it extremely light, which in the first cars means saving on the safety, however as there is a verion planned for Germany(where they need to be collision safe to get in) this is one problem they will likely solve, likely using expensive materials that will highten the initial price.

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Car Fueled by Air Not as Cool as Inventor Thought

Oct 09, 2007 15:24     

A good idea but may not live up to the hype. I got this link from their own website. http://www.addict3d.org/news/10003/Car Fueled by Air Not as Cool as Inventor Thought.html
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Simple Math...

Oct 09, 2007 15:26     

$2/$.10kWh = 18kWh in 4 hours = 4.5kW continuous draw, ~20 Amps @ 220 Volts. That might be a bit optimistic but not impossible. My 220v shop compressor is on a 30A breaker and compresses 60 gallons of air from 1Atm to 9Atm in about 5 minutes. And its nominal draw is obviously less than 30A, and 20A might even be a stretch. Multistage compressors are just as efficient with each molar volume at a specific compression ratio, so a multistage compressor consuming the same current would be capable of a theoretical 430 Atm in the same volume over 4 hours of running. Multistage compressors would have higher friction losses but nothing stratospheric. Now, what is the volume of the tanks? Heat from friction would not be an issue. Air powered tools often freeze up under heavy use. This engine would literally be frosty under even moderate use. Cold weather would not have much effect unless you 'filled the tank' in hot weather, then went somewhere dramatically colder. Even then a 50C temp swing near natural temps would be about a 20% decrease. So don't fill up in 40C weather then drive at -10C weather and expect to get your max use. Now, if you filled up at -10C, you'd probably be popping pressure release valves at 40C. Mufflers work just fine for compressors, and larger, higher quality compressors are usually quieter than the cheap ones. This volume and pressure would also require an air dryer, which muffles noise from compressors pretty dramatically. I still don't know about riding around on massive tanks pressurized to 4100 psi. At least gasoline requires an ignition source after the tank has ruptured. A carbon fiber tank that splits a seam is not going to be a pleasant thing to stand next to.

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Cost

Oct 09, 2007 15:30     

There is no way they could sell this for so cheap. The cost of raw materials alone drives the price up. Plus the short range sucks. Adding a gas engine to extend the range would increase the price and only make it no different than the current hybrids today. Good idea, just not practical.
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thanks for the calculation

Oct 09, 2007 15:43     

If it is correct; With P efficiency, 50 kilowatt powered car (about 67 hp) can run about 2.4 minutes by using 50 liter tank. Just google: 4 kilowatt hour/50 kilowatt * .5=? minute the result is 2.4 minutes. So we need a truck with a huge tank to drive for hours without refilling :)
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Calculations etc.

Oct 09, 2007 17:38     

Hi, Thanks for the calculation. This has spured me on to doing a few of my own. Some extremely broad assumptions here, but: 1l gasoline ~= 10kWh 25% efficiency = 2.5kWh Cost = $0.75/l, = $0.30/kWh delivered 1kWh electricity = $0.05 50% efficiency = $0.1/kWh delivered Say an economical gasoline vehicle uses 5l/100km. So thats about 50kWh, or 12.5kWh "delivered". The range they quote for the vehicle is 200km, so lets say it needs 25kWh of power delivered to do that. Lets guess 50% efficiency for this engine, thats going to need 50kWh, or 500l of compressed air tank storage. That sounds reasonable, given that they save a lot of weight in engine, cooling, etc. Lets also guess 50% efficiency on the compressor side, so it costs 100kWh to fill the tanks. At .5c/kWh, thats $5 - in the ballpark of what they quoted ($2), so perhaps I do believe them after all... But 3000 miles on a single tank for a hybrid version? OK, I figured that one out. They must be working on a way that you can use the compressed air tanks to store either gasoline or compressed air. So, if you fill up with 500l of gas, then sure you're going to get an incredible range!

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Calculations etc.

Oct 09, 2007 17:38     

Hi, Thanks for the calculation. This has spured me on to doing a few of my own. Some extremely broad assumptions here, but: 1l gasoline ~= 10kWh 25% efficiency = 2.5kWh Cost = $0.75/l, = $0.30/kWh delivered 1kWh electricity = $0.05 50% efficiency = $0.1/kWh delivered Say an economical gasoline vehicle uses 5l/100km. So thats about 50kWh, or 12.5kWh "delivered". The range they quote for the vehicle is 200km, so lets say it needs 25kWh of power delivered to do that. Lets guess 50% efficiency for this engine, thats going to need 50kWh, or 500l of compressed air tank storage. That sounds reasonable, given that they save a lot of weight in engine, cooling, etc. Lets also guess 50% efficiency on the compressor side, so it costs 100kWh to fill the tanks. At .5c/kWh, thats $5 - in the ballpark of what they quoted ($2), so perhaps I do believe them after all... But 3000 miles on a single tank for a hybrid version? OK, I figured that one out. They must be working on a way that you can use the compressed air tanks to store either gasoline or compressed air. So, if you fill up with 500l of gas, then sure you're going to get an incredible range!

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My Electric Ford Ranger gets 45 miles on 32KW

Oct 09, 2007 18:10     

It runs a lot longer than 2.4 minutes. Charging takes 6 hours @ 23Amps/240 Volts AC (it should go farther but has a current leak somewhere).
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Ford Ranger on compressed air...

Oct 09, 2007 19:56     

Excellent data point. So, if you need 32kWh to get your ranger 45 miles, then you would need something like 320l of compressed air tankage to get the same thing from compressed air (assuming equivalent efficiencies). I'm guessing you have something like 200kg of batteries - is that about right? So considering that, 320l of air tankage is also not unreasonable...
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Just to make a follow up on some of the calculation...

Oct 10, 2007 02:23     

Just to make a follow up on some of the calculations. Okay if need 32kWh to get your in a range of 45 miles then you need at least a: 32kWh/80Whl^-1 = 400 liter tank The mass of the air in such a tank is (P*rho*V) 0,4m^3*300bar*1,205kg/m^3 = 145 kg Just for the air I wanted now to find the weight of the shell itself but I cant really find a compressed Air tank which can operate with 300bar air. But here is another thing that we have not discuss. The air tank is of carbon fiber. That is really important because if it was made out of metal then it would weight a lot. And it has to be really strong to hold 400 l air at 300 bar. Here i think you are going to you more than one tank. Thats where i have some second thoughts. So if someone can find some spec on the tank please post them.

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Two questions

Oct 10, 2007 03:28     

In an accident, could the compressed air tank explode? And, if this car falls in water, can it float?
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Benefits?

Oct 10, 2007 08:04     

I think there are benefits to an air powered vehicle. One benefit would be a replacement for the gas powered fork lifts and flat bed vehicles used in enclosed spaces where one would not want toxic exhausts. Amusement parks is another good place to use them for the same reason. Where there is a need for a vehicle in an enclosed space, the air engine would be ideal.
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Why not add an ultra-capacitor and a solar panel to...

Oct 10, 2007 08:37     

Why not add an ultra-capacitor and a solar panel to supply an additional energy boot? That should expand the range a fair bit without falling back to diesel hybrid. Also, I wonder how much room their is for increase the tank compression. If they could double it, this car might actually be able to compete.
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300 Bar pressure...

Oct 10, 2007 08:42     

Wonder if they will make an espresso attachment. Watch out Starbucks!
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RE: Two Questions

Oct 10, 2007 11:26     

1. The compressed air tanks, according to the article, are made of carbon fiber, meaning they would not explode, but rather let the air out very rapidly through tears in the material. 2. Depending on how much the air is compressed, it may or may not float (my guess is that you'd have to be just about out of air for it to float). Adding air to an air tank actually makes it SINK, since it becomes heavier (assuming the water that it displaces stays the same, or in other words it doesn't get bigger, like a ballon does).

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Exploding tanks

Oct 10, 2007 14:35     

I think the "exploding tank" aspect needs some more investigation. There is a very good reason that they fill scuba tanks in a water bath - one exploding tank can really ruin your day! I heard an anecdote from a friend about a scuba tank that blew its valve while sitting in a car - not a rupture as such. They found the remains of the valve in the third cylinder of the engine - it had shot straight through the engine block! So, even if carbon fiber won't "explode", it could still rupture, and that would turn anything around it into potentially lethal shrapnel. The more I think about it, the more I feel that this idea just isn't going to be practical for passenger vehicles.

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Range

Oct 10, 2007 15:52     

If they can just increase the range and top speed a bit this could be a great step forward. I don't believe that the technical hurdles are that large and I don't share many of the concerns that others do about the tanks and their durability. I personally believe that if the floor of the vehicle was reinforced correctly that it would be much safter than toting around over 10 gallons of gasoline. I'm excited to see what the second generation of these vehicles will bring.

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Nope.. not safe

Oct 11, 2007 01:27     

The trouble with that much compressed air is that it is much too volatile to be safe, far more volatile than a full tank of gasoline. Orders of magnitude more volatile! Because, you can open a gas tank to atmosphere without it exploding all over the place. A car like this would be illegal in North America. There is simply no street safe enough to operate it on! Just imagine the tire on your car, at 32 psi they hold a frightfully large amount of pressure. You couldn't bleed a tire flat without freezing your thumb. Now type this into google: "300 bar = ? psi" and you'll discover they are contemplating 4300 psi!!! Of air? That's a pretty good trick to hold hydraulic oil at that pressure, a bloody miracle for air. Look again at the article: http://snipurl.com/1s1c2 7 km maximum range under ideal conditions? It looks like a right royal scam going on. Furthermore: unless the tanks use some kind of accumulator-style precharged bladder system, the pressure will drop off rapidly as the tanks begin to empty out. So, 500 litres of useful capacity becomes more like 800 litres of total encapsulated volume at the very least. So you end up with a tank that NEVER relaxes pressure so it is ALWAYS highly dangerous, even when flat out of air. Lastly: 500 litres is a tank about 34" in diameter by 34" long; 800 litres is about 40" in diameter by 40" long. Those are inside dimensions by the way. Lets do a simple hoop-stress calculation shall we. 4300 psi inside a 40" I.D. tank that is say, 1" thick. You'd have 86,000 psi hoop stress 42,000 psi longitudinal stress, or about 96,000 psi net stress. WOW! Also if it were a solid steel tank it'd weigh about 2200 lbs (40" ID x 40" long x 1" thick cylinder). Color me extremely skeptical! [We couldn't tell from your analysis. :) -Rick]

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discussion is finished :)

Oct 11, 2007 10:37     

From wikipedia: Gasoline contains about 34.6 megajoules per litre (MJ/l). My car has a 52 liter gasoline tank. If we want the same amount of energy as 300 bar compressed air, what is the volume of air tank? ((34.6 (megajoules / liter)) * (52 liter)) / (300 bar) = 59 973.3333 liter About 60000 liter!!! It means: ((60 (meter^3)) / ((4 / 3) * pi))^(1 / 3) = 2.42859006 meters radius sphere's volume. Quite infeasible. No need to mention safety because it didn't pass feasibility test.

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Discussion is not finished

Oct 11, 2007 14:26     

All that math was impressive but you didn't factor efficiency in, most of the power in gas is wasted in heat. Plus, the point was for inner city commutes and no gas bill. A less effective technology can easily be better if implemented properly. They had electric cars in the 1920s that were a lot better than the gas alternatives. Projects like the Killacycle show the potential for all electrics when done properly. Many university professors are self sufficient at home with solar power creating hydrogen for a rainy day and then selling the residual energy back to the power company. All of these things are doable, the key is simply the implementation and the will. (And not making electric cars look like kids toys)

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Discussion NOT finished

Oct 11, 2007 14:48     

Without even looking at your numbers, lets just assume you are right..a huge hole in your line of reasoning? Simple: you are assuming we need the same amount of energy as an internal combustion enegine car. The amount of energy per mile driven is NOT constant; it can be made much less, as it is for the MDI aircar. http://cyber-media.com/aircar
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Links for more about MDI

Oct 11, 2007 14:51     

The fan site listed below has links to all the main .com and .lu websites about the aircar, you can explore them for specs, launch any/all of them from the a fan site started many years ago from the associated mdiaircar yahoo group which now seems dormant..Fan site: http://cyber-media.com/aircar/
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More calculations

Oct 12, 2007 01:47     

Hi, Thanks for those links. So, from the MSI website, 300l of air tankage, at 300bar, can provide 46MJ, which is about 12kWh, or roughly the same energy as 1l of gasoline. That is apparently 90m3 of air, massing around 120kg (plus tankage weight of course). I am absolutely guessing here, but lets allow 30kg for the tank, so 150kg total. To put this another way, their system can store about 0.08kWh/kg. Not too far from current battery technology (.15-.3kWh/kg), and certainly a lot cleaner to manufacture and maintain. Still a long way behind gasoline's roughly 10kWh/kg. Still, a car that can travel any reasonable distance on the equvalent of 1l of gasoline is not going to be a big consumer reality any time soon, irrespective of the power source. And I am concerned that they very much gloss over the safety aspects. Never the less, definately an interesting technology to watch...

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Torque for hill climbing?

Oct 12, 2007 12:25     

Also, light weight means less traction in slippery conditions. I presume a battery powered on-board compressor for those crunch times. I like the idea of possibly getting 2 horizontally-opposed four-cylinder power plants into the same engine compartment, though. Having one running on petrol and the other on compressed air (increased weight, range, traction, carrying capacity, heat source for colder climates, safety) would require some interesting technology (computer control, dual transmissions, engineering for maintenance access) in order to gain the full advantage.

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Moisture

Oct 13, 2007 12:17     

As compressed air is released, it expands which not only produces the energy for propulsion but it also produces or releases moisture. This same moisture can also be trapped within the compressed air chamber and/or tubing. How will this be relieved especially within a cold air environment?
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Not releasing water ....

Oct 14, 2007 18:57     

Yo - Water in normal air can not be compressed, so compressing air "produces" water (not really, but for your purposes...), expanding air can absorb moisture. For practical evidence, traditional A/C units "produce" water from the compressor stage. Hope that helps.
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man

Oct 15, 2007 08:19     

Actually lot of waste heat from compression phase. Which if stored in a heat bank can be used to improve efficiency.IE Air is heated prior to its expansion.Thus can double efficiency and range. Effective heat storage can be chemical thus not necessary to have excesive weight or insulation.
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Relax a little will you? But, there are problems..

Oct 15, 2007 18:56     

1-compressed air has been stored in scuba tanks or paintball tanks for a long time. 2-the pressure of many paintball tanks (maybe also scuba) are of 4500 psi 3-the material of the tanks... same thing (it is always the same thing when a new power source comes out for cars.. "oh this explodes" "oh this explodes very much" "oh..........", enough?) Possible problems: A-single power source cars may have the following problem: range / size of tank B-refilling time: this is probably the biggest problem of them all!! it may be cheap to refill... but it would simply take ages more than most people want to spend in a "gas station" C-tank replacement: as far as I know, tanks need to go under a special test every 5 years or be replaced. I think the test is expensive, and replacing might even be more. Yet another payment and thing to take care of for the car (not to say that the money you save on gas wouldn't pay this, it probably does...)

Q report abuse vote down vote up Votes: +0

Why not have a quick disconnect so extra tanks carr...

Oct 16, 2007 22:04     

Why not have a quick disconnect so extra tanks carried in a separate compartment can be used as needed?
Al report abuse vote down vote up Votes: +0

This might help a little with the ozone BUT...

Jan 07, 2008 18:37