Now Here's a CLEAN CAR!

It looks to me as though the only question on the air car is whether a greater stored energy density can be achieved with compressed air or with batteries.

The cryogenic nitrogen car has an additional potential not mentioned in the article: A Stirling-cycle engine can run just as easily from a source of cold as from a source of heat; therefore the cold nitrogen could be used to run a Stirling-cycle engine, which would heat the nitrogen and vaporize it, and the now high-pressure nitrogen gas could then power the air motor.

(You can buy model Stirling-cycle engines that run on an ice cube, or ones that run on a flame, and I think maybe ones that can run either way.)

 

I really like that idea of compressed air. And you could probably be able to fill up at home.

 

Great article, Dave! Truly facinating.

Looking over the University of Washington Liquid Nitrogen car, I was struck from the picture of the prototype that:

• I know exactly where the picture was taken on the UW campus, and
• It appears that their prototype was built from one of the local ice cream mini-trucks (jeeps, actually) that drive around in North Seattle in the spring, selling ice cream to the local kids. (They're very North Seattle -- the trucks play classical musical to alert kids that they're in the area. :roll: )