Abstract
Powertrain electrification and lightweighting can lower light-duty vehicle (LDV) fleet energy consumption and CO_2 emissions. A stock turnover model of the LDV fleet is used to estimate the potential of powertrain electrification, lightweight materials use and vehicle size reduction for CO_2 emissions reduction and the impact on energy and automotive material use. 24 LDV types are considered, combining four powertrains, internal combustion engine vehicles (ICEVs), hybrid electric vehicles (HEVs), battery electric vehicles (BEVs), and fuel cell hybrid electric vehicles (FCHEVs); two glider types, conventional and lightweight; and three vehicle size classes, normal, compact and mini-sized vehicles. The case of Japan is studied, considering the base scenario and six alternative scenarios where HEVs, BEVs, FCHEVs, lightweight mini-sized HEVs, lightweight mini-sized BEVs and lightweight mini-sized FCHEVs are deployed. Compared to the 2050 baseline values of tank-to-wheel (TTW) energy consumption, 797 PJ/yr, and TTW CO_2 emissions, 53.1 Mt-CO_2/yr, maximum energy consumption and CO_2 emissions reductions of 563 PJ/yr and 49.0 Mt-CO_2/yr are obtained using lightweight mini-sized BEVs. Nevertheless, the largest energy consumption and CO_2 emissions reductions until 2029 and 2027 are achieved with lightweight mini-sized HEVs. Despite of aggressive lightweighting, iron and steel represent more than 30% of automotive material consumption by 2050.
