A Car that Runs On Air

The author of today’s article, Sheryl Canter, is an Online Writer and Editorial Manager at Environmental Defense.

In poking around the blogosphere recently, I found several references to a Popular Mechanics article about something called an "Air Car". Air Car?? What I read left me with some questions, so I found the inventor’s Web site and did some further reading.

It sounds like science fiction, but it’s true. A car that runs on air – compressed air – will be sold in India starting in August 2008. It’s designed mainly for city driving, and produces zero carbon emissions.*

Compressed Air Technology (CAT) has long been used to run power tools, but translating this to a car took 14 years of development effort for MDI, a small company based in France. The founder of MDI, an ex-Formula One engineer named Guy Nègre, describes his invention in this video:

The CityCAT (one of several models) is made of fiberglass with a radio-based electrical system that makes it extremely light. Retailing for just $12,700, the CityCAT can reach speeds of 68 mph, and travel 125 miles without refueling. It’s not as quiet as an electric car, but it’s much quieter than a gasoline-powered car. Another bonus: The air expelled from the exhaust pipe is clean and cold (about 59 degrees), and can be channeled to air condition the car.

Refueling is fast and cheap. With custom air compressor units, it takes just 2 to 3 minutes and costs $3 and change. Or tanks can be refilled by plugging into the electrical grid. That takes 4 hours, and uses about $2 in electricity. MDI also makes a hybrid version of the car with a gasoline-powered compressor. Both types will be available in 2, 4, and 6 cylinders.

MDI has signed agreements with manufacturers in many other countries besides India, including France, Germany, Spain, Portugal, Italy, New Zealand, Israel, and South Africa. But not the U.S. The air cars don’t pass U.S. safety standards – yet.

It makes me wonder… How crash-resistant does a car need to be for use in urban areas, where most of the time you couldn’t drive over 30 mph even if you wanted to? Imagine how much quieter and sweet-smelling New York City would be if all the cabs were air cars. Bicycle taxis are allowed, why not air cars?

*Clarification: It produces “zero emissions” in that clean, breathable air is emitted from the tailpipe. But of course emissions are produced in generating the electricity used to fill the compressed air tank.

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  1. greenchick
    Posted June 25, 2007 at 3:58 pm | Permalink

    This is pretty amazing. Another reason, to help keep our air clean. I came across a great contest for non-profit business professionals at http://www.svn.org/imaginewhatsnext They
    are holding a contest to reward business leaders for starting or running socially responsible companies. This seems to be a growing trend!

  2. Posted June 25, 2007 at 5:35 pm | Permalink

    Great car! I would like to see more like these in the future.

  3. anna.earthlawyer
    Posted June 26, 2007 at 1:35 pm | Permalink

    I can’t wait until they allow these to be sold here. What an amazing solution to a difficult problem! I imagine that our country will delay their entry into the market as long as possible, unfortunately- but we can hope and strive for the best! Now, if we could just get our electric utilities converted to clean energy…

  4. Posted July 6, 2007 at 5:22 pm | Permalink

    The air car can only produce more pollution, not less. Here’s why….The energy to compress the air comes from somewhere (such as an electric power generating station) which burns fuel. Compressing air, then expanding it in the car, is inefficient. Thus more fuel must be consumed to account for that inefficiency, thus more pollution is produced.

    There are a few limited situations where the reduced efficiency of compressed air is worthwhile, but a car surely is not one of them!

  5. Posted July 10, 2007 at 10:41 am | Permalink

    Darryl, your analysis isn’t complete enough to draw this conclusion. Yes, the electricity needed to create compressed air generates emissions, but it’s highly unlikely that these emissions are as much as that generated by a regular, gasoline-powered car, if for no other reason than the air car is vastly lighter and takes much less energy to move.

    The air car’s compressed air tank can be filled in 2-3 minutes at a pump, or 3-4 hours if plugged into an electric outlet. On this amount of energy, it can run 125 miles. How much gasoline would have to be burned to move a regular car that far, and how would those gasoline emissions compare to the emissions from a 2-3 minute use of a compressed air pump? I haven’t done the math, but it seems clear to me that the emissions for the air pump electricity would be far less than the emissions from the gasoline.

  6. Posted September 26, 2007 at 1:27 pm | Permalink

    I’ve been successfully debunking this air car for years. Author Guy Dauncy was my 1st major convert. Air powered vehicles have a long history, and always a short range. Independent testing of the Air Car found that it only went 37km on air alone, which is about the maximum possible. A tremendous amount of energy is wasted if the compressed air is allowed to cool, and it always is. A more serious design would have huge heat exchangers to re-warm the air during a multi-stage expansion. Moreover, a tank of compressed air does not have to mix with air to turn all of it’s energy into an explosion – it is just like dynamite in that respect. This project probably started off as a neat idea, but nobody did the math until they were in so deep they could just continue as a stock fraud.