You have probably already heard, probably through the media, of the - too - famous air car and its equally famous compressed air engine.
Since 1996, many reports and articles are devoted regularly to revive the, ultimately, false good idea of the air motor.
Indeed, the overall yield on the primary energy of the compressed air can only be bad (all the air manufacturers will tell you) that this is compared to a thermal car but also compared to electric cars which, themselves, still pose many problems and disadvantages. However, the air-car "concurence" directly the electric car (small "clean" urban movements).
The use of compressed air should, in our view, be limited to the recovery of braking energy with a completely independent on-board system with a main electric or thermal propulsion. That is to say that we should not be able to recharge with air: the autonomy of the tanks is limited to a few decelerations or accelerations (ie, at most, a few hundred kJ)…
The situation would obviously be different if the air was compressed was by renewable energy sources, but renewable energies are already lacking so wasting green energy by compressing air is it really wise?
In 2003, the Ecole des Mines de Paris carried out 2 studies on compressed air propulsion, you can download here. It is interesting, or rather dismaying, to hear from MDI, the company which developed this air motor, that they do not know these 2 reports.
To better understand the phenomenon of the "air car", here is a Investigation Complement investigation video broadcast a few days ago.