Tata Working on a Compressed Air Car
A car that runs on compressed air may be making its way to the market soon. Indian carmaker Tata is hoping to build a production model of the AirPod. The AirPod is based on technology that Tata licensed from MDI, a Luxembourg company. MDI has been working on the technology for several years but signed a licensing deal with Tata in 2007. A concept car was revealed in 2011 but a production model has yet to hit dealer floors.
The AirPod is an extremely light, one seater car that should be able to reach between 28 to 43 miles per hour. The AirPod is powered by a tank of compressed air instead of gas or electricity. Compressed air can be pumped into the car via a charging station or taken in while the car is moving using a small electric engine. Like many hybrids the AirPod will also recapture energy during the braking process.
In May, Tata successfully tested the engine in two concept cars. Since then Tata and MDI have been working to move the AirPod to the next stage, actually creating a production car that can be sold to consumers. If they succeed they could change the face of transportation by creating an emissions free car that runs on something as plentiful as air.
MDI is not the first company to work with compressed air engines. They were actually created over a century ago and were commonly used in mining operations until electric motors became widespread. Compressed air still powers pneumatic tools that are often used in auto shops.
A compressed air engine is very similar to an internal combustion engine. Fuel forces the pistons to turn a crankshaft, which powers the car. The main difference is that in the compressed air engine, air moves the pistons instead of gasoline. Swedish researchers have also worked with single-cylinder compressed air engines.
The main problem with compressed air engines is the power, or lack of power that is created. Compressed air alone will only get a car up to about 35 miles per hour. In order to supplement the power, the vehicle needs to take in additional air as it gets moving. This is done using an onboard air compressor. The compressor is usually electric or gasoline powered. While this will add to the complete emission picture of a compressed air vehicle, the total emissions are much lower than an internal combustion engine as the gas engine is not running at low speeds.
Range can be another limiting factor. The tanks that store the compressed air must be stronger than steel due to the pressure required to store the air. These tanks can only be so big due to weight which limits the total range of the vehicle. Completely filling a tank with an air compressor could take up to two hours making refueling a lengthy process. While range can be an issue, compressed air is much safer than compressed hydrogen or natural gas.
At this point in time, Tata is alone in the compressed air car field. Honda unveiled a concept car in 2010 but has gone no further in pursuing a production vehicle. If Tata is successful these cars could drastically reduce emission levels in India and around the world.