Compressed Air Cars

When I first wrote about cars powered by compressed air in 2008, I thought that the world had jumped back 100 years ago. Then, like now, companies were coming up with ideas to try and sell machines and many of the ideas being developed today were in existence a century ago but the underlying technology wasn’t there to make it cost effective to produce or viable to sell.

The use of compressed air to power a car is another idea that has been floating around for many years and over the past ten years has been getting some serious research dollars thrown at it – thanks to the fluctuating price of oil. The concept however, has been around for two centuries – use a pneumatic actuator to act as a source of power delivery. In the case of a car it is a sealed cylinder that has compressed air pushed in under pressure, this moves a piston down the cylinder, which turns a crankshaft – a very similar concept to the internal combustion engine. It is the air pressure changing in the cylinder that creates the useful kinetic energy to turn the shaft.

To improve the conversion of air pressure to kinetic energy, some designers heated the air or the engine to increase the pressure further – a sort of supercharging and other designers burned a fuel in the compressed air – similar to a jet engine – however not a true compressed air motor as it needs another fuel to act as the ignition source!

If you think about it, air goes in and air comes out, so there is no pollution other than the source of the power used to compress the air in the first place. As with any vehicle, there are dangers involved, especially if the car carries a compressed air tank.

So who is – or has tried – developing cars that use this type of propulsion? Firstly there is a company called Motor Developments International, a French company that has been developing concept cars for over 20 years. They intended to release a 3 wheeled model called the Air Pod and a more conventional looking 4 wheeler called the Air One, which is a hybrid with a small petrol motor.

Guy Negre, who ran the company had developed a two cylinder engine – using air from a tank. Negre had been clever in his business model, although after 20 years you would have thought that the world would have seen some of the cars in production. Negre realised that the real value was in the licensing and has sold 50-odd licences to build the cars all over the globe.

One licensee is Tata Motors, who have licensed the Air One, a five seater with a range of 90 kms or 56 miles – good for commuting. It was to be called the Tata OneCAT and was also to be launched in 2012. Five years on and the car is nowhere in sight – Tata have built out their range with conventional petrol and diesel powered vehicles.

IndraNet Technologies in New Zealand and Australia had also signed a licensing agreement but have not yet started to build. In fact, based on reports, IndraNet has had a checkered history of not making anything they have raised funds for!

Another Australian company to design a compressed air engine is Engineair. They have designed a rotary air engine. The Di Pietro motor, named after its designer is a super efficient motor, with minimal friction and very few moving parts to wear out. They have fitted it to very lightweight commercial utility vehicles that operate indoors such as in vegetable markets. Di Pietro’s background was working on the Mercedes-Benz rotary engine during the late 1960s before emigrating to Australia. One concern is that their web site hasn’t been updated in 7 years, so the technology could be still being developed further – the last report I read was from 2013.

Energine, was another licensee from South Korea who planned to build air hybrid prototypes with an electric motor to help with power delivery. Nothing can be found about this company any more and the top man appears to have been arrested for fraud!

I like the idea of compressed air power – if you can get the vehicle to generate enough power to compress as well as expand the air, you could have a vehicle that is totally self sufficient – if you had solar panels generating the electricity to fill the tanks when stationary, you could use it without causing any more greenhouse gases by replacing the need to draw from the electrical grid.

A great idea, however after many decades, we are still no closer to seeing a car driven by this fuel source – however many people seem to have invested (and lost) their money in the hope that this would take off. Guy Negre, the source of the current licencing structure, died in 2016 and this could mean that the concept will quietly go away until the next big breakthrough in technology – or the price of oil skyrockets due to increased political/military tensions in the oil drilling areas of the world.