India's compressed air car?

Question

A google search reveals that cars that run on compressed air seem to be plausible now - India supposedly is going to have a fleet of 6000-ish taxis running this year on compressed air. Does anyone know if this technology can be adopted for mainstream use, and, if so, why the heck aren't we pursuing this more fervently, instead of wasting so much time, money, and food on this ethanol boondoggle?

Answer 1

The problem with a compressed air car is that it's basically an inefficient electric car.  You're taking the energy needed to run the air compressor and putting it into the compressed air, which then mechanically pushes some pistons to make the car move.

This is inherently a less efficient process than simply storing the energy in a battery and using it to run an electric motor, which are on the order of 90% efficient.   Because air cars are less efficient, they have to be more lightweight, so they have difficulty passing crash tests in the USA.  That's why they're not being actively pursued here.

Answer 2

That sounds alot like a stirling engine. I think with some research and development a stirling engine could be put to good use in a car.

Answer 3

We aren't pursuing it because there's no particularly good reason to. What do you think the advantage would be?

This might make sense in the future if we develop an efficient way to produce electricity that we can use to compress the air. But currently we have no good way to do so.

Are you going to suggest building lots of nuclear power plants to make the compressed air? Even if so, doesn't an electrical car make more sense?

Answer 4

The laws of thermodynics state.

First law .... Energy is conserved

Energy in - energy out = change in internal energy.

Basically if you put 200 BTU's in a system you can not get 300 BTU's out.

Second law, (confusing and complicated)  The best explanation I have heard is.  We can not even get that.

We put 200 BTU's in, we can even get 200 BTu's back.

What does this mean for the compressed air Car.

ENERGY TO COMPRESS THE AIR>ENERGY PRODUCED BY UNCOMPRESSING AIR

It may be a more efficient than a gas or electric motor (I doubt that) It is not free energy.  Once you figure the energy to compress the air.  Remember we could probalbe build a gas car that got 100 mpg and went 30 mph a 2 seater.