Author Options:

Another car that runs on fresh air. Answered

Here's another chap with a car that runs on compressed air.

He's got more potential than past attempts, though - F1 engineering background, large backer, neat trick for extending range.

The video and Previous BBC "airing"
Canadian news article
Critical article from Oil Drum (Australian energy site)
Oil Drum: part 2
Air Car site


Another BBC article
MDI Engineering site (they make the engines)
Tata Motors (who plan to build the car)


Better to have a windmill powered air compressor.

arguably, this isn't a "clean" method b/c in order to compress the air you'd need an air compressor, which is usually ether gas- or electric-powered. if it's gas-powered, well, thats self-explanatory. but if it's powered by good ol fashioned electricity, the question of how clean the electricity is, per se, comes into mind. how was the electricity harnessed? there are some plants with cleaner methods than others. i find alternative fuels interesting, but I'm still for hydrogen power at the moment :]

Ah, but you need electricity to make the hydrogen, so we're right back where we started again.

The best way to think of hydrogen is as a temporary energy store - you can "carry" more energy in the form of hydrogen (running a fuel cell) than in a battery.

Generating the hydrogen is analogous to charging the battery.

The big downside to hydrogen is the need for high-pressure, cryogenic storage.

Exactly! I just like compressed air because it's a simple mechanism.

... a simple mechanism ...

Can't argue with that one!

Honestly I think hydrogen is a bit of a pipe dream for green, since it wastes a bit of energy in the conversion process, meaning that you'll need more green power to do the same job as a standard EV, thought the battery like fuel cells could be a bit more efficient...

It's at the compressor that the system becomes "clean" - be careful how you source the energy to run your compressor, and the system is as clean as you want. See my Feb 13th post for more.


10 years ago

How does it compress the air? (sorry, I haven't read the links :-P )

I think you use a standard compressor to charge the tanks in the car, and it runs from them. I'd like to know what the ratio of mileage per tonne of C02 is of compressed air compared to the mileage per tonne of C02 from an ordinary petrol car, because I wouldn't think it's more eco-friendly.

People seem to forget when they see things like this that the air compressors are often run directly from petrol engines anyway, and think "WOW! NO EMISSIONS!".

I presume that the early tests were run from ordinary diesel compressors, but it is at the compressor that "green" and renewable energy resources enter the picture. All an air compressor needs is something to turn its shaft - a diesel engine, an electric motor or a donkey walking in circles, it doesn't matter.

They cite two past schemes for storing energy as air pressure in underground caverns.

It is quite feasible that a small wind turbine or solar system could "trickle pressurise" storage tanks at home, and all a commercial "pressure station" would need to supply vehicles away from home would be a large underground storage tank and a power supply of some kind (which is where the "green" aspect comes in). I imagine inner-city stations would use mains electricity, but stations in rural areas could have solar and wind stations for power, or whatever is locally available (a small hydroelectric station, a wave-power station, or it could be situated next to a landfill and burn the methane directly).

kiteman, the hydroelectric seems wasteful, why do that when you could have a waterwheel (smaller scale ideas) suspended with one side running a compressor shaft directly and the other side a generator, or go with an electric car... Oddly the temping security guard rides an electric bike, a commercial one he got for around £600 but it's unbelievable, it's farily new and beats the older versions hands down, it actually took off quicker than me... He gets around 40miles a charge from it and it folds up!

"Hydroelectric" means any system that extracts energy from moving freshwater - I've seen designs for small turbine-looking things that are designed for using in small turbulent rivers. In some clever way, the rotor spins in the same direction no matter which way the water hits it. It doesn't have to mean a huge dam holding back a valley-full of water.

I know, I've been looking into small size systems as theres a river just at the bottom of my street, you don't need a head of water or anything, that's where waterwheels can become highly efficient, ones that use a backside drop, they turn what looks like backwards are as efficient as most turbines... I just meant that on a small user scale it would be more efficient to be direct about it, a waterfall on your land could be an excellent way to make it work...

Yeah, large-scale energy storage in pressurized caverns (or hydroelectric dams, for that matter - same idea, different medium) is surprisingly effective. I wouldn't be surprised if vehicle-scale pressurized air storage can be made more efficient than electrical batteries.

I've actually had some schemes for an air bike, only two problems exist, it would be loud, obscenely powerful and go for a long time, in america someone could fall off and it could continue for a good while... Well actually it would run with no gears, have up to three hours of go at full throttle, around five hours at half throttle, the only problem that really comes up is the motor I want to use can move a twenty tonne lorry at full belt, thought the now redundant motor is perfect for the job, the hammer action is broken but it still spins up fine, which is good, however it would sound a bit like a cross between a harley and a chainsaw... It would be able to reverse on under its own power aswell... Now it would cost alot to buy the first tank but 3000psi nitrogen tanks are dirt cheap to fill, mainly due tot he fact that many tyrefitters dislike using compressors, the tanks just do it, no messing about and no arsing about...

I thought of this 5 years ago!

They still beat you by three decades...

Well, sorry. Its not my fault I was born so late! I was only 11 then!

Edited - more references added.