The Center for Clean Products has conducted a life-cycle assessment involving a comparison of exterior body closure panels made of different lightweight materials (aluminum, carbon fiber-reinforced polymer [CFRP] and glass fiber-reinforced polymer [GFRP]), to steel closure panels weighing 220 lbs as the baseline. In an additional, more forward-looking assessment, a monocoque body made of a carbon fiber-based composite was assumed to replace a conventional steel body, resulting in a substantial weight reduction (more than 60%).
The primary results reveal that CFRP appears to be the least environmentally burdensome material in 9 of the 14 impact categories evaluated. This is mainly due to the fact that CFRP has the maximum weight reduction potential of all the materials evaluated (about 60% over steel), resulting in a much smaller quantity of material needed. Of the remaining 5 categories, aluminum has the lowest score in three categories while GFRP has the lowest score in two categories. Steel does not have the lowest impact scores in any of the categories examined.
In the monocoque analysis, CFRP's position is further strengthened (compared to the original assessment). However, its impact scores in three categories turn around from being lower than those of steel to being higher than steel. The major contributors in each case are various releases associated with using larger amounts of carbon fiber.