Compressed air is an energy vector that can be used, in a viable way, to transport both people and goods.
The main goal of Air Car Factories is to develop and manufacture a vehicle driven by a compressed air engine with a level of performance that will respond to the actual needs of today’s market. With this aim we have drawn up a full agenda and an R&D plan of action for production start up.

This is the world’s first air-powered car (AIR CAR) that has zero emissions and will be mass produced by next summer (2008).
The car has got some amazing technology behind it and is developed by Guy Nègre (an ex-Formula One engineer) for Luxembourg-based MDI.India’s largest automaker will be producing 6000 zero-emission Air Cars in August of 2008 for the Indian streets (when they say India is up and coming this takes things to another level).
The gas-and-oxygen explosions of internal-combustion models may become a thing of the past if the Air Car becomes a major success, as it uses compressed air and has many benefits for our environment.
The $12,700 CityCAT is just one of many Air Car models planned which this model can get to 68 mph with a range of 125 miles from the gas (filled up via custom air compressor units).
The amazing fact that it will then take only $2 to fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi…I so want one in this high taxed fuel world.
The bad side is that the Air Car is made of an all-glue construction which may mean it will never hitting the UK or American shores, but MDI has said they have signed deals to bring its design to 12 more countries (these include South Africa, Israel and Germany) so there is hope yet.Via popular mechanics.

When compressed air was first tried, it was found that the loss of power was enormous. It was difficult to store, for the air leaked rapidly away; it was expensive to generate, and there were thermo-dynamic difficulties in its use without number. When a thousand cubic feet of air is jammed into the space of one, a large amount of heat is developed, and in order to store and use the air this heat must in some way be drawn off. Similarly, air at high pressure, when released, cools rapidly. The result, if there be a sufficient moisture, is freezing and clogging. For a long time it was thought these difficulties were largely insuperable.

Now, however, these very difficulties are turned to a profit—to such excellent profit, indeed, as to afford an apparent paradox. It seems idle to assert that it is possible to get as much power out of a machine as you put into it—this means a frictionless and wasteless mechanism. And yet a very near approach to just this condition seems to have been made in the case of compressed air. This is due to the development of the reheating process. Lest the reader be not familiar with the technique of the subject, it may not be idle to explain its broader features. In the process of compression the air is sucked into a piston, and then rammed into a reservoir surrounded by a water jacket, the latter drawing off the heat generated in the compression. The machine which does this work is a beautiful affair of what is known as the four-stage type. That is to say, the air is first driven up to about eighty pounds pressure and cooled; then turned into a second cylinder, where it is compressed still further, then cooled again; and so on up to the desired point. Thus even at two or three thousand pounds pressure to the square inch the air within the reservoir remains at somewhere near the temperature of the outside atmosphere. But if the air be used in this condition, not only will a large share of the power employed in compression be lost, but it will, as already noted, have a tendency to freeze everything within reach. If, however, as it is released, it is passed through a heater or is shot through superheated hot water it will, under the well-known properties of air, enormously expand. In actual practice it has been found possible to add, by reheating, one horse-power to each horsepower developed by compression, at one-eighth or one-tenth the original cost of the latter. That is to say, if a given quantity of compressed air costs a dollar to generate, the further expenditure of ten cents in reheating will double its power to do work. Theoretically the total efficiency thus obtained is actually greater than if the same amount of coal had been burned in an ordinary steam-engine and the power thus generated used direct. In practical use it is slightly less.

To obtain maximum use of air’s internal energy (ambient heat), do not allow the air that goes to the first power stage in a multiple stage expansion to rise in temperature above ambient. Maximum practical cold production can be reached by means of first stage expansion with early cutoff, then heat can be added. Some heat (toward ambient but not above) should be absorbed just before first stage intake, such as electric heating pads on elbows where cold is naturally produced, and other places where expansion takes place as the air approaches the engine.

Add heat to engine air whenever possible; first absorb ambient heat, then recover compression heat, then add purposely generated heat, if any.
Reheating compressed air to raise pressure just prior to engine intake is much cheaper in energy cost than an equivalent pressure increase attained by compressing more air.
Regenerative braking works well with air cars, and compression braking saves brakes and heats the air in the tanks.

It takes less work to increase the pressure of a volume of air from 100 to 200 psi than it would take to increase the same air from 0 to 100 psi. This can be verified by looking at any air compressor power consumption chart ever published. It is the rationale behind the closed cycle pneumatic power plant, which can do more work with smaller machinery.

Any chance to boost the pressure of already compressed air instead of compressing atmosphere will lower the relative size of the machinery needed to do that task, because more energy per unit volume of compressed air is handled by a booster than by a normal atmosphere compressor with the same displacement.

It is possible to put low pressure air into a high pressure tank against very little resistance by taking advantage of the Bernoulli Effect, which is the answer to the 1870 physics riddle known as Maxwell’s Demon. Potential and kinetic energy can be caused to trade places so that each is used for what it does best, and neither gets in the way of the goal, which is to keep the tank full as cheaply as possible.

All compression work is lost as heat. This little-known fact is straight out of the textbooks.
The energy that pushes pistons is heat, not pressure, so if we arrange to use solar-source heat to run an air car, then the air car is a self-fueling solar air car.
The longer cold, partially expanded air stays in the engine, the more free heat it will absorb from its surroundings. To keep it moving slow, behaving more like a heat sponge, try the following: lower rpm, multiple-stage (compound) expansion, heat exchangers (no bends in piping) between stages.

Extra pressure needed for any reason as a part of the power process should be generated only as needed so that compression heat can be used immediately and storage pressure can be kept to a minimum. The more air you store in a given space, the higher the maximum storage pressure becomes.

Find ways to use compressed air at its full pressure, such as jet pumps and other pressure exchangers. Design around this concept, rather than using regulators to lower the air's pressure to that desired.

It’s almost too simple for words. It’s so easily missed because its discovery does little to gratify the inventor’s creative instinct, or the engineer’s hard-won high-tech education, or the tinkerer’s love of gadgetry. New inventions, theories, and gizmos are so unnecessary as to distract from compressed air’s ultimate secret, which is really just efficiency, inherent and designed-in.

Compressed air's inherent efficiency is made evident by these facts:

_Air is everywhere.
_Air contains solar energy.
_Compressing air is a simple process that makes its internal energy (solar heat) usable without altering the air chemically. No thermodynamic conversions or changes of state are necessary, eliminating wasteful steps.
_The energy wasted in compressing air takes the form of heat, which is air engine fuel, and is conservable for use.

Design efficiency is the need to go one step further than status quo convention in the production and use of compressed air. The two-step process of compressing and expanding air creates two opportunities to introduce efficient design measures, that is, to conserve energy.

_Means of expanding air can be provided to use more of the available energy before exhausting it, by way of a relatively efficient air engine as opposed to a commercial air motor.
_Means of conserving compressor work can be used to decrease the net cost of making compressed air.

The ultimate secret of compressed air is that to create a self-fueling pneumatic power plant, all you have to do is make the most of the energy contained in expanding air, and/or make the most of the energy invested in compressing air. Simply put, the self-fueling air engine is a natural phenomenon of ordinary processes, and not some aberration of fringe science or a result of exotic devices. This basic fact is easily proved mathematically using standard engineering formulas and charts. Gizmos and gadgets are fun, but unnecessary; they are the stuff of research institutes. The first goal should be to show an ordinary air engine running an ordinary compressor and keeping its own tank full in the process. I repeat: the math easily proves this possible.

The idealization of conserving compressor work would be to put the compressor in the tank. The fresh air brought in from outside the tank is compressed into the tank, and the work done in the compressing dissipates into the tank as heat, expanding the volume of air available to the engine as fuel. The increase in fuel value due to the conserving of compression heat represents a value beyond what one would expect from engineering charts but not beyond the scope of ordinary engineering formulas to quantify.

The idealization of conserving expansion potential is to expand the compressed air so slowly that its pressure never goes down, since the heat used to push pistons is replaced by ambient heat absorbed from the surroundings. This is straight out of the thermodynamics textbook.

The obvious impracticalities of these idealizations are beside the point; it remains only to identify means of going in their general direction. For example:

_An insulated shroud enclosing both the compressor head and the engine head would conserve much of the compression heat.
_A multi-stage engine with inter-stage ambient heaters, which runs at a low RPM, would squeeze lots of work out of a little air.
_Combining the two strategies could lead to the most practical design.

Gizmos can be added later—such as reducing compression work (as opposed to conserving the work of a normal compressor)—with a series of check valves (and/or jet pump in the tank) that allows low pressure air to be injected into a high pressure tank. Other possibilities include:

_heat pipes
_electric resistance heaters
_water-cooled compressors that dump heat into channels in the air engine block
_As a last resort, any air engine can be made more efficient by using combustible fuel to heat engine air till the Coefficient of Performance (COP—see heat pump basics) rises above unity, making a hybrid power plant without the noise, pollution, and expense of an internal combustion engine.

If not for compressed air’s simplicity, its use in solar power production would have been mastered long ago. We must stop flattering ourselves with our brilliant new ideas, and prove the self-fueling nature of air with basic designs that take advantage of air’s best feature: its ultimate simplicity.

FROM FALSE ANALOGIES TO FREEDOM FROM FUEL
To state that compressing air gives it the ability to do work is like saying that building a dam gives water the ability to operate a power-producing turbine. While these are true statements, they are not made in the scientific context of energy investments. It would be false to state that the work invested in compressing air results directly in the work compressed air can do, just as it would obviously be false to credit the work of building a dam for the quantity of water power thus made available. In both cases, the work done by the pressurized fluid is a result, scientifically speaking, of the sun’s energy, while the work of the compressor, like that of the dam builder, is an incidental investment—you might say an economical consideration or hardware cost—rather than a scientifically correct accounting of the energy invested that later pays off in the power made available.

WHAT’S RIGHT WITH WHAT’S WRONG WITH AIR
Some of air’s so-called disadvantages, according to the usual way of looking at things—a viewpoint that is built around using air for safety, portability, and convenience, not for efficiency—are some of its greatest advantages.
The classic case of this glaring discrepancy between standard thinking and air’s real potential is the assumption that air is self-defeating in any attempt to produce power because of the fact that it gets cold. The standard line goes like this: air enters a cylinder of an air motor and expands, becoming cold in the process. The air subsequently entering the cylinder will be cooled by the cylinder walls, robbing part of its power value before it can do any work. Effectively then, it is a self-defeating hope to try and use air efficiently. My rebuttal is that the cold produced by compressed air’s expansion in a cylinder is an advantage because it makes the machinery a sponge for heat in the surrounding atmosphere which, if absorbed into the system because of enlightened design work, becomes free energy for the piston to use.
Let’s face it: once Americans get even the vaguest inkling that anyone or anything could be considered wimpy, they shun it like the plague. Could it be that the general ignorance of compressed air’s subtle and misunderstood nature is a result of our macho nature, our fear of being associated with sissified ideas?
Once I called the manufacturer of a fairly efficient compressed air motor, and when I asked why the motor wasn’t being put in cars, the salesman I spoke to informed me that his boss would remind me that in order for the car to go anywhere, it would have to be followed by a semi truck carrying its compressed air supply.
Now if that isn’t self-defeating and wimpy, I don’t know what is. It’s downright Unamerican to give up so easily!
Similarly, it is thought to be ever-so ridiculous, that a compressor on-board an air car would be the silliest notion since self-chewing bubble gum. All that power wasted, for the little trickle of compressed air made available.
But wait a minute. In what way is all that power used?
It is used to make heat.
And what is it about compressed air that makes it capable of pushing pistons?
It’s the heat.
And what is it about expanding air that makes it seem so objectionable as a piston-pushing medium?
The cold produced.
And what does cold do to heat?
It sucks it up like a sponge.
Conclusion: the hotter air gets when it's compressed, the more heat is available to be conserved; the colder the air gets when it's expanded, the more ambient heat it can absorb from outside the engine.

March 19, 2007 Many respected engineers have been trying for years to bring a compressed air to market, believing strongly that compressed air can power a viable "zero pollution" car. Now the first commercial compressed air car is on the verge of production and beginning to attract a lot of attention, and with a recently signed partnership with Tata, India’s largest automotive manufacturer, the prospects of very cost-effective mass production are now a distinct possibility. The MiniC.A.T is a simple, light urban car, with a tubular chassis that is glued not welded and a body of fibreglass. The heart of the electronic and communication system on the car is a computer offering an array of information reports that extends well beyond the speed of the vehicle, and is built to integrate with external systems and almost anything you could dream of, starting with voice recognition , internet connectivity, GSM telephone connectivity, a GPS guidance system, fleet management systems, emergency systems, and of course every form of digital entertainment. The engine is fascinating, as is and the revolutionary electrical system that uses just one cable and so is the vehicle’s wireless control system. Microcontrollers are used in every device in the car, so one tiny radio transmitter sends instructions to the lights, indicators etc
There are no keys – just an access card which can be read by the car from your pocket.
Most importantly, it is incredibly cost-efficient to run – according to the designers, it costs less than one Euro per 100Km (about a tenth that of a petrol car). Its mileage is about double that of the most advanced electric carInnovation-At-Big-Companies Dec-07 (200 to 300 km or 10 hours of driving), a factor which makes a perfect choice in cities where the 80% of motorists drive at less than 60Km. The car has a top speed of 68 mph.
Refilling the car will, once the market develops, take place at adapted petrol stations to administer compressed air. In two or three minutes, and at a cost of approximately 1.5 Euros, the car will be ready to go another 200-300 kilometres.
As a viable alternative, the car carries a small compressor which can be connected to the mains (220V or 380V) and refill the tank in 3-4 hours.
Due to the absence of combustion and, consequently, of residues, changing the oil (1 litre of vegetable oil) is necessary only every 50,000 Km.
The temperature of the clean air expelled by the exhaust pipe is between 0 - 15 degrees below zero, which makes it suitable for use by the internal air conditioning system with no need for gases or loss of power.


How does it work?
90m3 of compressed air is stored in fibre tanks. The expansion of this air pushes the pistons and creates movement. The atmospheric temperature is used to re-heat the engine and increase the road coverage. The air conditioning system makes use of the expelled cold air. Due to the absence of combustion and the fact there is no pollution, the oil change is only necessary every 31.000 miles.


At the moment, four models have been made: a car, a taxi (5 passengers), a Pick-Up truck and a van. The final selling price will be approximately 5.500 pounds.

MDI recently completed an agreement with #1 Indian car manufacturer, Tata Group, which purchased licensing rights for India. This significant infusion of capital will allow MDI to finalize its technology for licensing throughout the world.
Tata Motors and technology inventor, MDI of France, sign agreement
MUMBAI, 5th of February 2007
Tata Motors, in keeping with its role as the leading company in India for automotive R&D, has signed an agreement, in yet another exciting engineering and development effort, with MDI of France for application in India of MDI’s path-breaking technology for engines powered by air.
The MDI Group is headed by Mr. Guy Negre, who founded the company in the 1990s in pursuit of his dream to pioneer an engine using just compressed air as fuel – which may be the ultimate environment-friendly engine yet. Besides, the engine is efficient, cost-effective, scalable, and capable of other applications like power generation.
The agreement between Tata Motors and MDI envisages Tata’s supporting further development and refinement of the technology, and its application and licensing for India.
Commenting on the agreement, Mr. Guy Negre has said, “MDI has for many years been engaged in developing environment-friendly engines. MDI is happy to conclude this agreement with Tata Motors and work together with this important and experienced industrial group to develop a new and cost-saving technology for various applications for the Indian market that meets with severe regulations for environmental protection. We are continuing the development with our own business concept of licensing car manufacturers in other parts of the world where the production is located close to the markets. We have also developed this new technology for other applications where cost competitiveness combined with respect for environmental questions has our priority.”
- About MDIMDI is a small, family-controlled company located at Carros, near Nice (Southern France) where Mr. Guy Negre and Mr. Cyril Nègre, together with their technical team, have developed a new engine technology with the purpose of economising energy and respect severe ecological requirements – at competitive costs.
- About Tata MotorsTata Motors is India’s largest automobile company, with revenues of US$ 5.5 billion in 2005-06. With over 4 million Tata vehicles plying in India, it is the leader in commercial vehicles and the second largest in passenger vehicles. It is also the world’s fifth largest medium and heavy truck manufacturer and the second largest heavy bus manufacturer. Tata cars, buses and trucks are being marketed in several countries in Europe, Africa, the Middle East, South Asia, and South East Asia and in Australia. Tata Motors and Fiat Auto have announced the formation of an industrial joint venture in India to manufacture passenger cars, engines and transmissions for the Indian and overseas markets. Tata Motors already distributes Fiat-branded cars in India. The company’s international footprint include Tata Daewoo Commercial Vehicle Co. Ltd. in South Korea; Hispano Carrocera, a bus and coach manufacturer of Spain in which the company has a 21% stake; a joint venture with Marcopolo, the Brazil-based body-builder of buses and coaches; and a joint venture with Thonburi Automotive Assembly Plant Company of Thailand to manufacture and market pickup vehicles in Thailand. Tata Motors has research centres in India, the UK, and in its subsidiary and associate companies in South Korea and Spain.

MDI Group, the French developer of the compressed air vehicle, and Zero Pollution Motors (ZPM) showcased MDI’s newest compressed air vehicle at this year’s New York International Auto Show (NYIAS) today, March 20. The vehicle was unveiled for for its first public appearance ever at the Automotive X PRIZE (AXP) booth at the show (see pictures).
The new MDI economy/utility car is one in a series of vehicles to be developed by MDI for production in various markets throughout the world. The vehicle is powered by the Compressed Air Engine (CAE) invented by Guy Negre, CEO and founder of MDI. Compressed air vehicles feature zero tailpipe emissions and high energy efficiency and represent an affordable, eco-friendly alternative to conventional gasoline powered vehicles and hybrids.
ZPM and MDI have entered a team to compete for the Automotive X PRIZE and will display the new vehicle at the AXP booth at NYIAS. The goal of the Automotive X PRIZE is to inspire a new generation of viable, super-efficient vehicles. The independent and technology-neutral competition is open to teams from around the world who can design, build and bring to market 100 mpg equivalent (MPGe) vehicles that people want to buy, and that meet market needs for price, size, capability, safety and performance. The size of the multi-million dollar prize purse, and the identity of the PRIZE’s title sponsor will be announced on March 20 at NYIAS.
ZPM plans to introduce a 6-seat, 4-door family-size version of the compressed air vehicle to the U.S. market. The ZPM model will achieve over 100 MPGe and over 90 mph, have zero to low C02 emissions, offer plenty of space for luggage, meet all safety requirements, and cost no more than an average economy to mid-size vehicle. The first ZPM manufactured compressed air car will roll off the production line in 2010 and will cost around $18,000.
MDI and ZPM will enter two vehicles in the Automotive X Prize: the U.S. production 6-seat, 4-door family-size model will compete in the Mainstream Class; and the 2-door, 3-seat economy/utility model on display at NYAIS will compete in the Alternative Class. The economy/utility model will be produced by MDI for sale in France and elsewhere 2009 at a price of beginning at around $5,000-$6,000 for the basic model.

When we reported last year that Tata Motors would begin producing it in India. Now the little gas-free ride that could is headed Stateside in a big-time way.

Zero Pollution Motors (ZPM) confirmed to PopularMechanics.com on Thursday that it expects to produce the world’s first air-powered car for the United States by late 2009 or early 2010. As the U.S. licensee for Luxembourg-based MDI, which developed the Air Car as a compression-based alternative to the internal combustion engine, ZPM has attained rights to build the first of several modular plants, which are likely to begin manufacturing in the Northeast and grow for regional production around the country, at a clip of up to 10,000 Air Cars per year. And while ZPM is also licensed to build MDI’s two-seater OneCAT economy model (the one headed for India) and three-seat MiniCAT (like a SmartForTwo without the gas), the New Paltz, N.Y., startup is aiming bigger: Company officials want to make the first air-powered car to hit U.S. roads a $17,800, 75-hp equivalent, six-seat modified version of MDI’s CityCAT (pictured above) that, thanks to an even more radical engine, is said to travel as far as 1000 miles at up to 96 mph with each tiny fill-up. We’ll believe that when we drive it, but MDI’s new dual-energy engine—currently being installed in models at MDI facilities overseas—is still pretty damn cool in concept. After using compressed air fed from the same Airbus-built tanks in earlier models to run its pistons, the next-gen Air Car has a supplemental energy source to kick in north of 35 mph, ZPM says. A custom heating chamber heats the air in a process officials refused to elaborate upon, though they insisted it would increase volume and thus the car’s range and speed. “I want to stress that these are estimates, and that we’ll know soon more precisely from our engineers,” ZPM spokesman Kevin Haydon told PM, “but a vehicle with one tank of air and, say, 8 gal. of either conventional petrol, ethanol or biofuel could hit between 800 and 1000 miles.” Those figures would make the Air Car, along with Aptera’s Typ-1 and Tesla’s Roadster, a favorite among early entrants for the Automotive X Prize, for which MDI and ZPM have already signed up. But with the family-size, four-door CityCAT undergoing standard safety tests in Europe, then side-impact tests once it arrives in the States, could it be the first 100-mpg, nonelectric car you can actually buy?

This six-seater tax, which should be available in India next year, is powered entirely by a tank filled with compressed air.
By Matt Sullivan
Published in the June 2007 issue.

India’s largest automaker is set to start producing the world’s first commercial air-powered vehicle. The Air Car, developed by ex-Formula One engineer Guy Nègre for Luxembourg-based MDI, uses compressed air, as opposed to the gas-and-oxygen explosions of internal-combustion models, to push its engine’s pistons. Some 6000 zero-emissions Air Cars are scheduled to hit Indian streets in August of 2008. Barring any last-minute design changes on the way to production, the Air Car should be surprisingly practical. The $12,700 CityCAT, one of a handful of planned Air Car models, can hit 68 mph and has a range of 125 miles. It will take only a few minutes for the CityCAT to refuel at gas stations equipped with custom air compressor units; MDI says it should cost around $2 to fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi. Drivers also will be able to plug into the electrical grid and use the car’s built-in compressor to refill the tanks in about 4 hours. Of course, the Air Car will likely never hit American shores, especially considering its all-glue construction. But that doesn’t mean the major automakers can write it off as a bizarre Indian experiment — MDI has signed deals to bring its design to 12 more countries, including Germany, Israel and South Africa.