SAVINGS OF MATERIAL RESOURCES AND CARBON EMISSIONS WHEN CONVERTING FOSSIL FUEL CAR TO ELECTRIC : A CASE STUDY FOR SWEDEN

Abstract: Transportation in Sweden currently accounts for one-third of domestic GHG emissions. Thereof more than 90 % are allocated to road traffic with passenger cars being the largest contributor. Hence, the Swedish government adopted stringent climate policies to cut transport emissionsby 70 % (compared to 2010) latest until 2030. Electrification is seen as one of the key strategies to mitigate climate change and to accomplish set climate goals. Hence, estimation and quantification of electric vehicle life cycle carbon footprints is of major interest to understand their environmental performance. As part of this study lifetime burdens for gasoline, diesel and battery electric vehicles were contrasted. Nominal end of life was assumed to be reached after 200.000 km. The life cycle inventory was conducted based on market and literature data and by employing the open-source LCA tool carculator. Impacts on material resources were assessed by various materialization models for vehicle glider, combustion powertrain and electric powertrain. Additional impact categories such as formation of fine particles, freshwater use and terrestrial ecotoxicity were included. Results showed that lifetime carbon footprints of electric vehicles in Sweden are 45-51 % lower compared to conventional diesel and gasoline drives. Per driven kilometer, electric vehicles caused 137,46 g CO2-eq./km, diesel vehicles 249,28 g/km and gasoline vehicles 282,75 g/km. Savings of electric drives mainly originate from vehicle operation (zero tailpipe emissions) and low carbon electricity generation (predominantly hydropower, nuclear energy and wind energy). Lifetime battery charging according to the Swedish energy system was found to provoke 1,03 t of GHG emissions. This is ten times lower compared to average EU loads. Modeling results for electric vehicle manufacturing disclosed a total carbon footprint of 17,63 t CO2-eq. with a significant portion of 5,99 t originating from lithium-ion batteries. This is 57-63 % higher than estimated production footprints for fossil fuel vehicles with the same amount of 8,63 t CO2-eq. allocated to the glider. However, performed sensitivity studies revealed significant potential to cut emissions from battery manufacturing with transition to European sites. Replacement and conversion of vehicles from the Swedish fleet was assessed according to both, a fixed lifetime perspective of 200.000 km and year-by-year scenario models. Three different paths projecting development of the vehicle stock until 2030 are presented. Results of this work showed that vehicle conversion offers potential to save about 1.191 kg of material resources (thereof 728 kg ferrous metals, 104 kg aluminum, 149 kg plastics and 210 kg other materials). Corresponding savings in production emissions comprise 8,63 t CO2-eq. through reuse of the vehicle glider. From a nationwide perspective, up to 34 % of annual GHG emissions and up to 60 % of the annual material demand could be saved. Results further suggest a target value of around 3,8 millionelectric vehicles by 2030 to achieve aspired emission limits.