Life Cycle Assessment Of Electric Vehicles’ Carbon Emission And Its Impact On The Environment

China is considering various ways to cut carbon emissions as the increasingly severe situation of greenhouse gas emissions at home and abroad.The electricity is used as EVs’power,which is without pollutant emissions in the use phase.In this case,the development of electric vehicles is seen as a measure to reduce carbon emissions in transportation field.However,China’s current power structure is coal-based and high-carbon,so that it is still controversial whether electric vehicles can truly reduce greenhouse gas emissions compared with GICEV in terms of full life cycle.Therefore,it is necessary to evaluate the greenhouse gas emissions of electric vehicles from the perspective of full life cycle.This study is based on theoretical analysis,data collection and model building,etc.This paper built the appraisal model of the whole life cycle of electric vehicles,using the Hybrid Life Cycle Assessment method and China’s energy structure data in 2018.The carbon emissions of pure electric vehicles（PEV）,plug-in hybrid electric vehicles（PHEV）and gasoline internal combustion engine vehicles（GICEV）of the same domestic SUV model are calculated.In order to get a more accurate and reasonable result,this paper divides the life cycle into fuel cycle and vehicle cycle,adopts the process-based life cycle assessment method for the fuel cycle,and adopts the hybrid life cycle assessment method for the vehicle cycle.Vehicle weight and power structure are two important factors influencing greenhouse gas emissions of electric vehicles.In this paper,linear regression analysis is used to determine the linear relationship between vehicle weight and greenhouse gas emissions.This paper selects the power structure of China in four scenarios:2018,2020,2030 and 2050 for calculation.Through the establishment and calculation of the above model,it is found that in the fuel cycle and vehicle cycle,the PEV has the highest greenhouse gas emissions,followed by the PHEV,and the GICEV has the lowest greenhouse gas emissions.Over the full life of a car,the PEV emits the most greenhouse gases,followed by PHEV and GICEV.The full life cycle greenhouse gas emissions of PEV are487.96g CO₂-eq/km,which is 1.19 times that of GICEV and 1.06 times that of PHEV.Especially during the WTP phase,electricity emits far more greenhouse gases than gasoline.As for the influence of vehicle weight and power structure on greenhouse gas emissions of electric vehicles,the research results show that vehicle weight is linearly correlated with greenhouse gas emissions.For every100kg increase in vehicle weight of electric vehicles,the energy consumption demand of electric vehicles will increase by 0.0051kwh/km.As the proportion of clean energy in the power mix increases,the greenhouse gas emissions from electric vehicles decrease.In the future,with the vigorous development of clean energy in China,the greenhouse gas emission of electric vehicles will be far lower than that of fuel vehicles.Therefore,while vigorously developing electric vehicles,we should also pay attention to raising the proportion of clean energy in our country.