Carbon fiber production is more energy intensive than steel production (by mass). However, Revolutionary cars are lighter and their manufacturing is simpler, so their total manufacturing energy is much lower than for steel cars.
The nominal Revolutionary auto in Reinventing Fire will weigh 50% less than today’s model. Moreover, it uses significantly less material. The Revolutionary auto will use 6x fewer pounds of carbon fiber reinforced plastic (CFRP) than today’s cars use steel.
Carbon fiber energy intensity is also likely to decline further with time. Furthermore, recycled CFRP material is 10x less energy intensive than virgin CFRP material (15–33 MJ/kg), though its uses are more limited.
RMI analysis using data from:
A. World Steel Association. 2011. “Selection and Design for Car Door Outer Panel.” Steel University. link
Suzuki, Tetsuya and Jun Takahashi. 2005. “Prediction of Energy Intensity of Carbon Fiber Reinforced Plastics for Mass-Produced Passenger Cars.” Japan International SAMPE Symposium, December 29. link