By Evan Ackerman
The media has been getting a lot of mileage out of compressed air powered automobiles, touting (in the midst of remorseless witticisms of the sort that I was just guilty of) the fact that air is both plentiful and environmentally friendly… But I don’t entirely agree. The following video, from the Science Channel, profiles Motor Development International’s forthcoming Air Car:
After the jump, I hope you’ll enjoy a brief rant about why this sort of thing doesn’t entirely make sense.
If you pause this particular video 1:33 from the end, you’ll notice a bunch of storage tanks accompanied by a box that looks suspiciously like an air compressor. The video talks about how cheap easy it is to refuel the car, but they go out of their way not to discuss in detail the fact that compressing air takes energy, energy which is likely piped straight from your local coal-burning power plant. Furthermore, you’re taking electrical energy and converting it to mechanical energy to compress the air, which is then stored and converted back into mechanical energy again in the car’s engine to drive the wheels. As anyone who has taken freshman physics will recall, every time you transfer energy from one type to another, you lose some.
So basically, compressed air is just being used as a storage medium for energy. It’s certainly true that other energy storage mediums (say, batteries or hydrogen) might be more expensive or more dangerous or both, but it seems as though when it comes to environmental impact (and perhaps even efficiency), a lot of these air powered car claims are just full of… nonsense. I applaud the fact that such innovations are being pioneered, but I feel like we (as potentially environmentally conscious consumers) deserve full disclosure as to what the total costs and benefits are, both environmental and financial.
[ MDI Air Car ]
