Air-powered cars? Not energy efficient enough (Update)

Three years ago, I wrote a post saying that air-powered cards are not energy efficient enough to be used for most transportation uses. Three years later, only one thing has changed: Guy Nègre, the inventor of the air-powered car, died on June 24, 2016 (75 years old) without seeing his invention reach commercial success.

Zero Pollution Motors, a U.S. licensee of the technology, promises that you can buy a car next year (2019). It's always next year; in 2019, I expect that it will be 2020. I hope that anyone who made a deposit on a new car in 2015 has gotten their money back.

There is talk about Tata in India selling an air-powered car in 2020. However, the video I saw showed both three-wheeled and four-wheeled cars, indicating that the design isn't far along yet. (In the United States, a three-wheeled car is considered a motorcycle for regulatory purposes, which have much weaker security requirements than four-wheeled cars do.)

One thing the YouTube videos mention is that the cars are as light as possible. If these light cars were powered by a gasoline engine or an electric battery, they would have good gas mileage or range on a charge. Comparing these light cars to a conventional sedan is preposterous. I am getting 45+ miles per gallon in my 2017 Honda Accord Hybrid and it's a good sized car.

Scam alert: Do not make any investment in a company developing an air-powered car or give them a deposit on a new car. Likely, you will never see a return for your money. Shiva Vencat, CEO of Zero Pollution Motors, LLC has at least two funding sites trying to raise money.

I stand by my claim three years ago: Air-powered cars are not energy efficient enough for everyday use by Americans or Indians. I hope that, now that Mr. Nègre has died, this concept will fade into oblivion.

Air-powered cars? Not energy efficient enough

Three years after this post was published, I published an update here.

The most recent version of an air-powered car, first introduced by Guy Nègre in 1991, was featured on Shark Tank recently. Robert Herjavec is willing to invest $5 million into Zero Pollution Motors provided that they negotiate a North American license from Guy's company, Motor Development International. Currently, ZPM only has a license for Hawaii. Autoweek covered the story here.

Don't expect to see these cars on the road any time soon. Guy has been flogging this idea for over 20 years now with only prototypes to show for it. In 2007, he announced that Tata Motors had licensed the technology and would manufacture cars in India but a visit to Tata Motors' Web site shows no mention of air-powered cars. To my knowledge, Tata has not sold a single air-powered car.

Most people see the appeal of the concept. Where is the problem? It's in compressing the air for the car. Compressing air produces heat, which is typically lost, reducing efficiency. On the flip side, in the car, expanding the air absorbs heat which means the air needs to be heated, reducing efficiency. One way around this is to capture the heat and store it in a battery, using that energy to heat the air when it is used in the car. The end result is that an air-powered car is not sufficiently energy efficient to be practical.

I could see using air power in situations where energy efficiency is not a factor but convenience or access to compressed air is. For example, in an electrical power plant, the waste heat from the boilers could be used to compress the air, reducing the overall energy cost.

Part of the Shark Tank pitch was the concept of using "turnkey micro-production factories" to build the cars locally. With the car already being impractical, saddling it with an unrealistic manufacturing model will surely doom it. Just as Tesla has one manufacturing plant, only one manufacturing plant is needed to serve North America.

One final point: Neither Ethan Tucker or Pat Boone, the presenters on Shark Tank, appear to have any experience building or selling cars. Ethan, at least, is listed on the management page of ZPM.

I wish Mr. Nègre the best, but the physics are against him.