The Environmental Opportunities and Challenges of Composite Cars
Examensarbete för masterexamen
Industrial ecology (MPTSE), MSc
The transport sector faces several challenges when it comes to reducing its contribution to global warming and dependence on fossil fuels. This means that the transport sector needs to find alternative energy sources for its vehicles as well as to decrease the energy use in the use phase of the life cycle. This can be achieved by turning from vehicles with conventional internal combustion engines to electrical vehicles as well as to reduce the weight of the vehicles. The latter can be accomplished by substituting conventional materials with lightweight materials such as carbon fiber composites. However, there are also solutions on how to combine these strategies where the energy is stored in the body, which will reduce the mass of the vehicle as a consequence of reduced battery size. The aim of the thesis was to assess the environmental impact of two composite vehicles based on either carbon fiber reinforced polymers or structural batteries as well as to give suggestion on how these materials can substitute conventional materials to reduce the weight while keeping or increasing the system performance. This implied a conceptual design of a conventional battery electric vehicle where the components were replaced with either carbon fiber reinforced polymers or structural batteries. This resulted in three conceptual vehicles based on different materials which functioned as input data to the inventory analysis of a cradle-to-grave life cycle assessment where the vehicles were assessed according to global warming potential, crustal scarcity indicator and cumulative energy demand. The result showed that both carbon fiber reinforced polymers and structural batteries have the potential to reduce the weight of a conventional battery electric vehicle of approximately 30-50% while keeping or increasing the mechanical and electrochemical performance of the vehicle. The result showed that the vehicle based on carbon fiber reinforced polymers provides environmental benefits over a conventional electric vehicle, while structural batteries cause more environmental impact. However, the result indicated that the carbon fiber reinforced polymers and structural batteries could decrease its environmental impact drastically if the energy use was reduced in the carbon fiber production as well as the structural batteries manufacturing process in addition to using fossil carbon lean energy system.
Multifunctionality , Lightweight Materials , Structural Batteries , Carbon Fiber Reinforced Polymers , Life Cycle Assessment