Alternative fuel cars used to be anathema to gearheads, including automotive writers. But these days, it’s a different story. Alternative cars are becoming more efficient and more practical, and examples like the all-electric BEV Tesla Roadster are cool in their own right. This isn’t the main reason, though. We understand that there is a limited supply of oil on the planet, and we still want some to be around for our Ferrari Californias and Ford GTs in 20 years. We want to save the gas for the cars that really need it.
Jay Leno had some interesting thoughts on the matter. “…much like the automobile was the savior of the horse. You know, in the cities…the horse would be whipped, and left dead, and when the car came along, it freed up the horse to be used for recreational purposes, and just for…the beauty of the animal. And I think [alternative fuel cars] will be the saviors of our sports cars.”
I find myself in complete agreement. And despite the fact that right now, in my opinion, the automakers of the world have yet to successfully produce a viable solution (the Chevy Volt is too expensive, the Nissan Leaf takes too long to charge, the Tesla likes to fall apart), I’m pulling for them.
But the one I can’t get behind is the Compressed Air Technology vehicle. Yes, it’s a car that runs on compressed air. Think about the scene in Jerry Bruckheimer’s remake of Gone in Sixty Seconds when the giant air tank is punctured and flies around crashing through buildings and making a hobby of mayhem.
On second thought, don’t think about that. Think about an impact wrench. It’s driven by compressed air, and the car works on the same basic principle. It’s nothing particularly new. The Victorian age of engine discovery is dotted, here and there, with examples of functional air engines. Pneumatic air trains were used in Europe for mining operations. The Plongeur, the first mechanical submarine ever invented, used a compressed air engine as far back as 1863. There was even a model airplane, the first one to fly under its own power, which used an air engine. It was invented in 1879. And in 1903, when the automotive fuel market was still up for grabs, a London firm called the Liquid Air Company even tried their hand with air-powered cars.
Perhaps, though, you weren’t paying attention to this history lesson because you were stuck on my impact wrench illustration. Because you know that every movie in which a hero picks up a nail gun and starts shooting at bad guys is wrong. Air tools, you’re thinking, are hooked up to compressors. And compressors are powered by electricity, gasoline, or diesel fuel. Therefore, since the more complicated a machine gets, the less efficient it gets, why not just cut out the middle man?
The idea is that a large, centralized compressor would be stationed at every filling station. No more huge, expensive fuel tankers lugging around loads of petrol. Just a huge, industrial, electric compressor, filling up your compressed air car’s tanks in about five minutes. So the chief need, and the universal bemoaning of all alternative fuel pioneers, is infrastructure. But unlike stations for hydrogen, compressed natural gas, or even electricity, they don’t need to draw their fuel from elsewhere. They can just pull it out of the atmosphere.
It sounds like a perfect solution, right? Right, if you’re only considering the refueling process. But as to the engine itself, there is one glaring problem. It’s not very efficient. If you compress air to 4,500 psi, it contains about 50 watt-hours of energy per liter. Gasoline, by comparison, pulls about 9,400 watt-hours per liter, a fairly significant gap.
And since the puny little pneumatic engines can’t seem to twist the cap off of a root beer bottle, the cars themselves have to be extremely light to even move. They are made of less durable, less crush-resistant materials, and the chances of a compressed air vehicle on the market today passing the NHTSA’s crash tests are exactly equal to my chances of getting a date with Natalie Portman.
It’s an interesting idea, but in my most-humble-in-the-world opinion, compressed air is not the answer. As you guessed, however, I know what is.
When Jay Leno offered the quote above, he was talking with Top Gear’s James May about the Honda FCX Clarity, which uses a hydrogen fuel cell and drives just like a normal car. Once again, the problem is infrastructure, as right now hydrogen stations exist solely in California, but Hydrogen is the most abundant element in the entire universe, so finding a little and adding some to every gas station in America doesn’t seem like much of a stretch.
I just hope Honda, and the other automakers of the world, get to it soon. I don’t own a Ford GT, but if, someday, I inherit one from a long lost billionaire uncle, I want to be able to fill the tank.
Images courtesy of Tata Motors.