Life Cycle Assessment Of EnergyUse,Carbon Emissions And Cost Benefit Of Electric Vehicles

All countries are giving substantial attention to electric vehicles?EV?for the relief of the petroleum crisis and the reduction of greenhouse gas and air pollutant emissions in vehicle operation stage.However,it should not be ignored that the energy consumption and emissions of upstream vehicle fuel and materials production still exist.Therefore,a life-cycle assessment?LCA?and cost benefit analysis are proposed in this study to evaluate the energy savings and emissions reduction of EVs and their social cost influence.Based on theoretical calculations,data analysis,and experimental tests,this research constructs a localized LCA model including the vehicle cycle and fuel cycle with temporal characteristics.This study constructs a complete material cycle database including material mining,transportation,production,vehicle manufacturing,usage and displacement and achieves integration with the fuel cycle model.The main optimizations of the LCA model are concentrated on the battery evaluation module based on the powertrain selection and the real world on-road fuel economy correction module.This article systematically evaluates the influence of the fossil energy consumption and CO₂ emission on the electrification of both light-duty vehicles and buses.The LCA model is applied to evaluate the cost benefits of different promotion strategies in light of maximizing the CO₂ emission reduction to help the government make decisions.The batteries are proven to be the key parts that the affect the vehicle cycle of EVs and that provide life-cycle energy saving and emission reduction benefits.For example,the nickel-cobalt-manganese lithium battery constitutes 41-54% of the vehicle cycle fossil energy consumption of battery electric vehicles?BEVs?.The most important factors in the high energy use contribution are the battery energy density,the energy consumption in upstream production process,the material regeneration ratio and the coal power ratio.Generally,the EVs achieve life cycle energetic and environmental benefits compared to internal combustion engine vehicles?ICEVs?,with the BEVs able to achieve 33% and 18% reductions in fossil energy use and CO₂ emissions,respectively.Because of the rapid battery energy consumption reduction,the EVs can achieve higher energy saving and emission reduction benefits in the future.For example,in 2030,the CO₂ emissions of BEVs are projected to fall to 126 g/km,resulting in the reduction of ICEVs expanding to 40%.Furthermore,the life-cycle energy savings and emissions reduction of EVs needs to be combined with regional characteristic conditions to carry out a differentiated evaluation.The results indicate that the EVs could attain additional CO₂ emission reductions under the conditions of congested traffic and high vehicle load?e.g.,opening air-conditioning or reaching full passenger load?.For example,an electric bus has a 12% reduction in CO₂ emissions compared to a diesel bus under congested traffic conditions,whereas under normal traffic conditions,the reduction is only 3%.This study establishes a quantitative response mechanism for the emission reduction of EVs to the grid mix,the relative fuel economy,and the total activity level.It is indicated that EVs need to consider the system design of the vehicles,the piles and the stations to reduce the charge loss.This research analyzes the cost benefits of EVs in both early and mature market scenarios,including the BEVs and the charging stations.In the fast charging and battery swapping modes,the equivalent annualized costs of BEVs are 1.9 and 2.6 times those of ICEVs under the premise of government subsidies,which reduces their original cost by 16%.The ratio of BEVs to stations is proven to be the most important factor in favor of the annualized cost control of BEVs among the single-factor influence comparisons.When one ICEV is replaced by a BEV,the specific amounts of life-cycle CO₂ reduction under the incremental cost in the fast charging and battery swapping modes,are 301 and 13 kg/10,000 RMB,respectively.Fast charge,a type of light resource burden model,has a cost benefit comparative advantage.If a mature BEV is operated in congested cities with a high clean electricity proportion,it can even achieve a win-win situation of cost and emission reduction.Hence differential marketing in each region should be based on the results of a cost benefit evaluation as well as the life-cycle energetic and environmental benefits,and the government subsidies should make enhancing the pure electric travel rate a primary goal.