What will be the material of choice for the bodies and structures of the first generation of electric cars? The Tesla Model S which is expected to debut in late 2011, will use aluminum alloy body panels. The highly publicized Roadster, which will cost twice as much, will use carbon composites.
The Tesla Model S
The critical factor is processing time. Hand layup of fiber combined with cure times work fine for an aircraft such as the Dreamliner. But that won’t cut it for production models of cars, even if production only reaches around 20,000 units. As reported by Design News, Plasan Carbon Composites is developing new technology that will cut process times, but - at least as far as Tesla is concerned — it apparently won’t be ready for prime time in 18 months.
Companies such as Alcoa would love to see aluminum used for the bodies of higher-volume electric cars. But steel, albeit newer and lighter steels, will often be the material of choice because of cost considerations. One engineering analysis “shows that it takes 9 years or 122,460 miles, at a gas price of $2.53 per gallon for aluminum structured vehicle to offset the total cost for steel structured vehicle.” Certainly, aluminum will be an important player for many structural components in cars. As reported by Design News, GM engineers selected forged aluminum wheels for the Chevy Volt.