Others raised issues with the energy required to compress air. This is frequently neglected, but is NOT trivial for air as it is not trivial for systems which compress natural gas to 3000 - 5000 psig for natural gas vehicles. Adding the electricity cost is essential! It seems the article is saying that $2.00 will get you 125 miles range. That implies a public (not home) high pressure dispensing and thus *should* have electricity cost already included... but be wary. The numbers sound fairly attractive, but I'd need more details to do the energy analysis.

One thing people have missed is that there is a big thermodynamic problem with compressing a gas into a tank and then running off the accumulated pressure. The compressed gas gets (Boyle's Law) quite a lot hotter as it is compressed. Unless the tank is very well insulated, as it loses this heat and drops back to room temperature, you lose pressure (and range) -- a big loss of energy. These systems need to take great pains to conserve the enthalpy of the compressed air. That's a major reason why to date, there have been no practical public highway compressed air vehicles. They are more feasible for short term / short range use on scooters, fork trucks, etc. inside large factories (no emissions inside the building). In that application they are easily "charged up" and the slower travel speeds mitigates the need for serious crash protection. The fairly short time (hours, not many days) between recharges reduces the need for exotic tank insulation schemes.

Compressed air is DEADLY. Trucks carrying compressed air are REQUIRED by law to display hazmat warning signs.

Can't wait for the first traffic accident that sets off the tanks in this crackerbox. The ambulance-chasing lawyers will line up to sue the pants off of the company and anyone driving one for putting such a danger on the road....

i think its great, no nasty batery's (chemicals) quick recharge at the station or a slower at home.

A friend of mine told me about these a while ago, and that even if you uses a normal car engine to compress the air for these you'd be getting the equivalent of over 100 MPG. So, most sources of energy you use to fill this up will still make it a green car.

Not so green, depending on what powers the compressor.

Electricity from burning coal? Or perhaps a large stationary engine?

OK the car itself is clean. "

I don't know of any car that is 100% green. Oh yeah but a hybrid is much better because where you may live it may use nuclear or a hydro dam? Please. Studies are showing that hybrids will pollute more in the long run than some gas cars/SUVs/trucks.

Electricity from burning coal? Or perhaps a large stationary engine?

OK the car itself is clean.