Electrification of New Zealand transport: Environmental impacts and role of renewable energy

Abstract

New Zealand's goal to be carbon neutral by 2050 has led to the development of strategic policies and schemes to encourage the use of electric vehicles (EVs). However, most studies are focused on the greenhouse gas emissions of EVs while limited studies are available on their other potential environmental impacts. Using life cycle assessment (LCA), the environmental impacts of EV adoption, specifically the battery electric vehicle (BEV), were assessed to determine the future environmental challenges for New Zealand. Due to 87.1 % share of renewable sources of electricity generation in New Zealand in 2022, EV adoption has demonstrated its strong potential to reduce the CO2 emission of the transport sector. Results showed that lithium-ion battery (LIB), including production and disposal, is the major contributor to the environmental impacts of BEV adoption. The direct environmental impacts of BEV in New Zealand range from 0.34 % to 42.5 % across its life cycle. The results are sensitive to the assumptions of the driving range and number of LIB replacements where they could increase up to 34.5 % per km and up to 48.9 % per replacement of LIB on environmental impacts, respectively. Scenario analysis also showed that when the renewable energy share in electricity production is increased to 100 %, the environmental impacts of the BEV life cycle could be reduced by up to 14.5 % while it could decrease by up to 69.6 % in New Zealand. Additionally, reusing the spent LIB for other purposes would have the least environmental impacts on disposal among the options considered in the study. Therefore, New Zealand would benefit the most from BEV adoption by generating 100 % electricity from renewable sources, and developing policies and schemes to repurpose LIB at its end of life.