If powering a car by compressed air sounds a little strange to you, consider this: Every vehicle with an internal combustion engine runs on compressed air. An internal combustion engine operates by drawing air into its chamber, then compressing and exploding the air with the help of gasoline. The power of the explosion turns the wheels of the car.
But what if the air entering the engine were already compressed? You wouldn't need an explosion, which means you wouldn't need the fuel to create the explosion.
Motor Development International, a French company that has licensed air-powered engine technology to some carmakers, figured out a way to get compressed air into a car. An on-board compressor that plugs into a wall outlet sucks in air from the surroundings and compresses it to 4,500 pounds per square inch. The air is stored in tanks under the car and slowly released to provide automotive force.
Watch a video on MDI's technology and air cars here.
One of the companies that has licensed the technology from MDI is Zero Pollution Motors, based in New Paltz, N.Y. The start-up expects to start selling its air car in the U.S. by 2011. The air car carries MDI's compressed-air engine and a small conventional engine. It travels about 20 miles on air alone, after which the engine takes over.
The engine also works the compressor, so the conventional-fuel-to-air-power cycle keeps repeating itself, enabling the car to travel hundreds of miles before needing its compressed-air supply replenished.
Detractors of the technology point out two main drawbacks: compressors release only about 25% to 30% of the energy required to compress the air, and it takes too much electricity to fully load the air car's compressor.
Undaunted, ZPM is forging ahead. Says its CEO: "We've got a lot of people who wanted the car yesterday."