2. Scope of this Study
2.1. Regions for This Study
2.2. Vehicles Assessed in This Study
2.4. The Scope of the Assessment
3. The Calculation at Each Phase of the Life Cycle
3.1. Vehicle Production Phase
3.2. Fuel Production, Fuel Combustion and Electric Power Generation Phase
- The CO2 emission factors of the fuel production in each region were cited from the LCA database ”GaBi”  ; data was referenced from 2013. Each system boundary for gasoline and diesel fuel is from resource extraction up to service stations. The emission factors of the fuels in “GaBi”  are specified with the amount of CO2 emissions by 1 kg fuel [kg-CO2/kg], therefore, the density values of fuel (gasoline: 0.727 kg/L, diesel: 0.828 kg/L)  were used to convert [kg-CO2/L] into [kg-CO2/kg].
- The CO2 emission factors of gasoline and diesel fuel combustion were cited  which were 2.28 kg-CO2/L for gasoline and 2.62 kg-CO2/L for diesel respectively and they were used in all five regions covered by the study. For both gasoline and diesel fuels, the CO2 emission factors of fuel combustion  are 5 to 8 times greater than those of fuel production  which varies from region to region.
- The CO2 emission factors of the electric power generation in each region were cited from ”GaBi”  ; data was referenced from 2013. The system boundary for the electric power generation is from energy resource extraction to transformation of electric energy to low voltage as the grid mix.
- CO2, ICV (FP, FC) = the amount of CO2 emissions in the phase of fuel production and combustion [kg-CO2],
- CFFP = CO2 emission factor of fuel production [kg-CO2/L],
- CFFC = CO2 emission factor of fuel combustion [kg-CO2/L],
- EICV = fuel efficiency of ICV [km/L],
- LD = lifetime driving distance [km].
- CO2, BEV (EG) = the amount of CO2 emissions in the phase of electric power generation [kg-CO2],
- CFEG = CO2 emission factor of electric power generation [kg-CO2/kWh],
- EBEV = Electric efficiency of BEV [km/kWh].
3.3. Maintenance Phase
3.4. End-of-Life (EOL) Phase
4.1. Effects of Lifetime Driving Distance
4.2. Regional Difference of the CO2 Emissions between Internal Combustion Engine Vehicles (ICV) and Battery Electric Vehicles (BEV)
4.3. Effects of the CO2 Emission Factor of Battery Production
5.1. Concern for the Setting of the Lifetime Driving Distance
5.2. Source of the Regional Differences of the CO2 Emissions between ICV and BEV
5.3. Estimation of the CO2 Emission Factor of Battery Production
- This study focused on the regional differences of the CO2 emission on the fuel production, electric power generation, and fuel combustion phase (i.e., vehicle use stage) but the CO2 emission on the vehicle and parts production phase is assumed to be the same for all regions.
- As the Joint Research Centre in the EU mentioned , the reuse and recycling of lithium-ion batteries is important to mitigate the CO2 emissions because it can avoid productions of new materials or parts, but it was out of scope of this study because there are not sufficient data of recycling in each region.
- The CO2 emissions in the use phase were calculated based on the fuel/electricity efficiency values of type approval test in each region. These values can be different from the values by real driving conditions.
- The uncertainty of cited data from references were taken care of in this study, but this study did not holistically perform a sensitivity check to examine which data could change the results widely other than battery production.
Conflicts of Interest
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|Reference||Studied Region||Studied Vehicles||Lifetime Driving Distance [km]||Estimation of Battery Production||Fuel Efficiency/Electric Efficiency||CO2 Emission Factor of Electricity|
|Ellingsen et al. ||Europe||ICV *1 and BEV *2|
from A (mini size) to F (luxury size) segment *3
|180,000||Referring to own earlier study ||ICV: average of actual ICVs (NEDC) *4|
BEV: estimating from the relationship between electric efficiency and weight of actual BEVs
(European average mix )
|—The life cycle Climate Change Potential of the F segment BEV was 1.7 times higher than that of the A segment BEV.|
—The CO2 emissions in the use phase of BEVs became lower when its electricity was coming from energy source of lower CO2 emission factor such as renewables.
|Mayyas et al. ||US||ICV (GE *5, HEV *6, plug-in HEV) and BEV with lightweight technologies||320,000||Referring to some other studies|
(120 kg-CO2- /kWh)
|Estimation from running resistances and energy for driving force, assuming US driving cycle (55 % FTP-75 *7 and 45 % HFET *8)||0.8515|
(US average mix)
|—The life cycle CO2 emissions of BEV and plug-in HEV were region dependent due to regional source of power generation. In the case of the US, HEV showed lower CO2 emissions than BEV and plug-in HEV.|
|Messagie ||European average and each country||ICV, BEV||200,000||Referring to Peters et al. |
(55 kg-CO2- /kWh for LMO battery*2*9)
|ICV: European fleet average, augmented by 35% to reflect real driving conditions based on Fontaras et al. |
BEV: Real driving efficiency based on De Cauwer et al.  (average of BEVs from A to C-segments)
(European average mix )
|—BEVs showed significant lower CO2 emissions, compared to ICV in most European countries.|
|Ou et al. ||China||ICV (GE, DE *10, Natural gas), BEV||240,000||Referring to GREET 2.8 |
(30 kg-CO2- /kWh)
|Referring to some other studies, e.g., 6 L/100 km for GE ||0.539 (by natural gas single cycle)|
0.485 (by natural gas combined cycle)
|—BEV reduces life cycle greenhouse gas emissions by 36%–47% compared to GE.|
|Sharma et al. ||Australia||ICV (GE, HEV, plug-in HEV) and BEV||150,000||Estimation by referring to some other studies||Australian Urban Drive Cycle (AUDC)||1.04 (Australian average mix).||—Regarding larger size vehicles, BEV shows lower greenhouse gas emissions than GE, but higher than HEV and plug-in HEV.|
|Vehicle||Gasoline Engine Vehicle (GE)||Diesel Engine Vehicle (DE)||Battery Electric Vehicle (BEV)|
|Battery capacity [kWh]||-||-||35.8|
|Fuel / Electric efficiency*1||US (5cycle)||13.2 km/L||-||5.75 km/kWh|
|Europe (NEDC)||19.6 km/L||26.3 km/L||7.87 km/kWh|
|Japan (JC08)||19.0 km/L||21.6 km/L||8.06 km/kWh|
|China (NEDC)||16.1 km/L||-||7.87 km/kWh|
|Australia (NEDC)||17.2 km/L||-||7.87 km/kWh|
|Literature||Cathode Type*1||CO2 Emission Factor |
|Zackrisson et al. ||LFP||166|
|Majeau-Bettez et al. ||NMC||200|
|Amarakoon et al. ||NMC||121|
|Ellingsen et al. ||NMC||172|
|Part Name||Reference||Referenced Data of CO2 Emission [kg-CO2]||Apply to|
(Body, tires, interior, etc.)
(76.8 % of overall production)
|GE, DE, BEV|
|Gasoline engine and transmission||JLCA ||1274|
(23.2 % of overall production)
|Diesel engine and transmission||JLCA  modified||1539 (20.8% higher than the gasoline engine)||DE|
|Electric drive unit parts|
|CO2 factor: Average of Table 3|
Capacity: Table 2
(177 kg-CO2/kWh × 35.8 kWh)
|Motor||Hawkins et al. ||1070||BEV|
|Inverter||Hawkins et al. ||641||BEV|
|Part Name||Maintenance Interval|
|Tire||40,000||108||JLCA ||GE, DE, BEV|
|Lead-acid battery||50,000||19.5||JLCA ||GE, DE, BEV|
|Engine oil||10,000||3.22||JLCA ||GE, DE|
|Radiator coolant||27,000||7.03||JLCA ||GE, DE|
|Li-ion battery||160,000||6337||Table 4||BEV|
|Process Name||CO2 Emission [kg-CO2]|
|Shredding and sorting||24|
|Area||DIP [km]||Fuel and Electric Efficiency||Relative Value of CO2 Factor * for Electricity|
|GE [km/L]||BEV [km/kWh]|
|Area||DIP [km]||Fuel and Electric Efficiency||Relative Value of CO2 Factor * for Electricity|
|DE [km/L]||BEV [km/kWh]|
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