(Tata, by the way, is the same company that is offering its People’s Car, the Tatanano which shocked the world recently with its less than $2500 starting price. Concern was raised among environmentalists that the potential of millions more cars on the planet wasn’t helpful.)
Negre, who invented the air-power technology, says that Tata will be the only large car company allowed to build cars and use the technology for other purposes. He wants large numbers of investors to build smaller plants scattered around the globe. The plants would build cars and sell them directly to consumers. Up to 80 percent of parts could be locally-sourced, creating jobs. Emissions from shipping parts thousands of miles would be eliminated. Cutting out the middlemen — direct factory to consumer sales —would cut costs as well. With hundreds of factories worldwide, he’s looking at one percent of global market share of automobiles - about 680,000 cars a year.
Under the hood of an MDI car is more than just a horizonally-opposed air powered piston engine. The Compressed Air Technology (CAT) includes two types of engines: Mono and Dual-Energy. Mono engines run on compressed air only in urban environments. Dual-Energy engines have a hydrocarbon fueled burner which heats air in the cylinders to increase pressure on the pistons. The addition of a combustible fuel means more power and extended range. The addition of an external heat source acting on the cylinders makes the engine design a close cousin of a Stirling engine.
The car model that Tata Motors will be selling is a version of the OneCAT. MDI’s website gives that model a top speed range of 55 - 68 miles per hour and a full tank range of 62 to nearly 500 miles. The significant range increase is due to the addition of heat source. Fuel for the burner can be bio-based or petroleum. On long distance runs the Dual-Energy CAT should achieve 120 miles per gallon. Around town on air-only fuel economy will be higher.
From a specialized, powerful air pumping station, pressure tanks can be refilled in about 3 minutes. At home, using the on-board compressor, filling takes about 4 hours. One can imagine solar-powered air filling stations for true full cycle zero emission transportation.
The engine is made of modules comprised of two opposing cylinders. Modules can be bolted together to make 4 or 6 cylinder engines, for instance. Current engines underdevelopment have power outputs ranging from 4 to 75 horsepower. Further development is planned for engines of 200 horsepower and higher to use in buses and trucks. The company says dozens of modules could be bolted together for even greater output for stationary applications.
The wide range of engine sizes possible with CAT makes for a wide range of possible applications - cars, trucks, buses, electric power generators, tow tractors, forklift trucks, agricultural tractors, outboard motors even engines for light aircraft.
Tata under its agreement is already thinking about power generators for remote use. In power generator mode the engine runs on fuel - anything available - to generate power as needed, or compress air. In emergency situations stored compressed air could run a CAT generator.
There’s more than the company talks about as well. One can also imagine using the technology as part of an energy storage system for solar or wind power. Excess energy from either source could be stored as compressed air by way of an electrically-driven compressor.
There’s another added value in the technology as well. The engines, being somewhat similar to conventional internal combustion engines, share similar time-tested production techniques - casting and machining for example - and are able to capture the wonders of volume production to keep costs down.
The technology seems like a winner. But if it weren’t for carbon fiber it wouldn’t be possible.