Air-Powered Hybrid Cars Coming

Jokes about “being full of hot air” aside, a pnuematic hybrid car is very close to production. While it’s not going to be seen in the USA (at least not right away) PSA – that’s Puegeot Citroen – has officially begun developing a car that will be partially powered by compressed air.

The compressed air car is a pipe dream, but a compressed air HYBRID is very feasible. So feasible that PSA is getting ready to build them.

Why Use Compressed Air Hybrids?

There are a few good reasons to use compressed air in a hybrid, especially if you compare it to a battery-electric hybrid.

1. Compressed air is efficient. Storing energy as compressed air is surprisingly energy efficient…it’s one of the reasons that air tools are still very common in industry (that and the fact that compressed air tools are smaller and safer than comparable electric tools).
2. Compressed air storage systems are cheap compared to batteries. If you compare the cost of buying a battery pack for a hybrid to the cost of buying an air tank, it’s not even close. Ditto for the components needed to turn compressed air into forward motion.
3. Compressed air is safer than chemistry. Hybrid batteries come in two basic flavors – nickel metal hydride (NmH) and lithium ion (LiON). These battery packs are full of corrosive chemicals, operate at relatively high voltage, and lithium ion batteries can even “run away” and catch fire without careful computer control.

So, as you can see, lots of good reasons to use compressed air.

NOTE: Battery chemistry is immensely complicated…the explanation above oversimplified things quite a bit. The current Prius, for example, uses a battery with nickel, cobalt, and manganese, which Toyota calls a “tri-metal” battery rather than a nickel metal hydride…but you get the idea.

The trouble with compressed air is capacity. A relatively huge air tank isn’t going to take your vehicle nearly as far as a comparably sized battery pack.

Still, if a good sized tank were paired with a fuel efficient engine and used on a tiny little car the size of a Scion iQ, you could see substantial performance at minimal expense. Peugeot is saying that they can develop an affordable car using this technology that will get more than 100mpg. That’s awesome.

According to Peugeot, a car the size of a Scion iQ could get over 100mpg with a compressed air hybrid system, at a lower cost than a comparable battery-electric hybrid.

Here’s to hoping someone figures out a way to make this system work on cars of all sizes…nothing would please me more than to drive a truck that runs (at least partially) on air.