I noticed that the video is five years old, so I'm guessing this particular product has died, but you can make one on your own. My husband's physics teacher made one and used it as a lesson in why the idea doesn't work. First, the amount of energy you can get out of compressed air is abysmal because most of the energy is lost in the thermodynamic exchange before it ever even has a chance to become 'fuel'.
IEEE (Institute of Electrical and Electronic Engineers) explains it this way:
The “thermo” of thermodynamics—the unstoppable flow of heat—makes pneumatic propulsion a considerable engineering challenge. The molecules of oxygen, nitrogen, and other gases in air give off heat when compressed, representing a loss of energy up front. Do the compression quickly, before the heat can dissipate into the surroundings, and the losses rise further. And the trouble only mounts when all this compressed gas is later released from the tank. The same molecules cool when they expand, hence the chill on your hand when you empty a spray can. Expand the gas slowly, and the pneumatic equipment can stay warm by reabsorbing energy from the atmosphere. But power-hungry vehicles must expand the gas quickly, so they are subject to extreme cooling, which hampers the engine or, at worst, freezes its air-feed lines.
And while compressed air is inexpensive, you also have to fill up considerably more often and the output is comical. The top speed has ranged from the commercial version's 18 mph to the professor's 'generous' 25 mph! That's not even legal driving speed on most streets. Second, the compressed air is not 'clean' since it still uses the power grid (powered by, you guessed it, fossil fuels) to compress the gasses. The only difference, just like electric cars, is that the fossil fuel is burned in an factory, not your car. According to
this article, compressed air could cause as much as twice the CO2 emissions of gas powered cars because of the inefficiency of compressed air. The article also compares energy efficiency of compressed air to battery and gas. Compressed air only has 12% the energy of battery and 1% the energy of gas. 1%!
Basically it
sounds like a good idea, but the reality is you're better off with a bike.
Posted: Sat Jun 06, 2015 8:29 am