Compressed air cars are the ultimate romantic vision of our transportation future. A car powered by air? What could be better than that? A lot of things, it turns out. According to “Economic and Environmental Evaluation of Compressed Air Cars,” a paper published in Environmental Research Letters (ERL), compressed air cars scored worse than electric vehicles on energy use, greenhouse gas emissions, and life-cycle costs. The cars are, in other words, just plain inefficient.
All is not lost for air car devotees, however. While the ERL paper shows that compressed air hold less than 1% of the energy of gasoline, and that cars powered by the stuff could only travel 29 miles before a recharge, hybrid compressed air cars are viable–and could even compete with hybrid electric vehicles.
That’s good news for researchers banking on hybrid technology, but disappointing for the slew of companies (Tata, MDI, K’Airmobiles) hoping to make big bucks on compressed air cars. Of course, these companies probably already know that the technology is bunk, or at least nowhere near ready for production. Tata postponed its compressed air car indefinitely, and the other companies haven’t said a word on when (or whether) their air cars will be ready. But we’ll be still watching the New York-based startup Zero Pollutions Motors closely–the company claims it will have an efficient air car ready in the U.S. as early as 2012.