This is the car your all talking about, the Tata Nano, powered by the Compressed Air Engine (CAE) and claimes some 100 + mpg, that's hydro-carbons, no power stations involved, unless you include any energy generated in it's manufacturing.
The concept is similar to the Hybrid cars currently available, but instead of generating and storing electricity in large battery banks for bursts of inertia, air is compressed and stored in a compressed gas tank and used for these bursts of inertia.
The concept is not new in fact it has been around for a couple of centuries, in the form of pneumatic locomotive engines
http://en.wikipedia.org/wiki/Pneumatic_motor it doesn't depend on the wind blowing, has no other emissions apart from some moisture (anyone who has worked with compressed air will relate to that) further, no oil is used in the engine therefore it is entirely hydro-carbon free
The technology in this instance, has been developed in France by Motor Development International (MDI) Angelo Di Pietro (Engineair Pty Ltd) in Australia has developed a more radical holistic approach insomuch as he has developed small rotary compressed air engines, one for each wheel, which reduces the overall energy consumption to go from A - B and the working parts involved in a, let's say car...anyone who is really interested, drop me a PM and I can give you some further information...bosshogg MSc. Advanced Sustainability for the Built Environment. :evil: