Air Cars Proven to be Waste of Energy

Graph - energy vs. km for alt-fuels

In brief: A new study shows that air-powered (usually compressed air) cars are inefficient and worse than gasoline-powered vehicles.

The word


Cars like the AirPod above run on compressed air. The air is stored under high pressure in a tank and released under the control of the throttle to turn the axle, moving the car.

A new study published in Environmental Research Letters, October-December 2009 issue, titled Economic and Environmental Evaluation of Compressed-Air Cars shows that these vehicles are inefficient and costly.

Since compressed air holds only about one percent of the energy of an equivalent amount of gasoline (when including the energy required to compress it), the carbon footprint of the compressed-air car is over twice as large as a gasoline car.

Obviously, this makes battery electrics and other alternative energy cars much more efficient by comparison.

Energy/km in alt-fuels

Other alternative uses of compressed air, which weren't included in this study, but referenced are ICE-pneumatics and possible hybrid-electric-air pump schemes.

In an ICE-pneumatic setup, an internal combustion engine provides the power to compress air from the surrounding atmosphere and push it through to turn the axles or wheels. In a hybrid-electric pump, the same principle applies using an electric motor.

And so ...

This is bad news for India, the compress-air car capital of the world. It's not likely that compress-air vehicles were ever to be more than novelties.

Photo credits: AutoblogGreen

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