Estimation of CO2 Emissions of Internal Combustion Engine Vehicle and Battery Electric Vehicle Using LCA

Ryuji Kawamoto,Hideo Mochizuki,Takahiro Nakano,Masayuki Motohashi,Atsushi Inaba,Yoshihisa Moriguchi,Yuji Sakai

doi:10.3390/su11092690

Ryuji Kawamoto, Hideo Mochizuki + Show 5 more

Open Access

https://doi.org/10.3390/su11092690

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Abstract

In order to reduce vehicle emitted greenhouse gases (GHGs) on a global scale, the scope of consideration should be expanded to include the manufacturing, fuel extraction, refinement, power generation, and end-of-life phases of a vehicle, in addition to the actual operational phase. In this paper, the CO2 emissions of conventional gasoline and diesel internal combustion engine vehicles (ICV) were compared with mainstream alternative powertrain technologies, namely battery electric vehicles (BEV), using life-cycle assessment (LCA). In most of the current studies, CO2 emissions were calculated assuming that the region where the vehicles were used, the lifetime driving distance in that region and the CO2 emission from the battery production were fixed. However, in this paper, the life cycle CO2 emissions in each region were calculated taking into consideration the vehicle’s lifetime driving distance in each region and the deviations in CO2 emissions for battery production. For this paper, the US, European Union (EU), Japan, China, and Australia were selected as the reference regions for vehicle operation. The calculated results showed that CO2 emission from the assembly of BEV was larger than that of ICV due to the added CO2 emissions from battery production. However, in regions where renewable energy sources and low CO2 emitting forms of electric power generation are widely used, as vehicle lifetime driving distance increase, the total operating CO2 emissions of BEV become less than that of ICV. But for BEV, the CO2 emissions for replacing the battery with a new one should be added when the lifetime driving distance is over 160,000 km. Moreover, it was shown that the life cycle CO2 emission of ICV was apt to be smaller than that of BEV when the CO2 emissions for battery production were very large.

Highlights

In response to the awareness of human induced climate change in the past decades, the international policy agenda has been driven toward greenhouse gas (GHG) reduction
The amounts of CO2 emissions of Gasoline Engine Vehicle (GE), Diesel Engine Vehicle (DE) and battery electric vehicles (BEV) were calculated in the European Union (EU) and Japan, while those for GE and BEV were calculated in the US, China, and Australia
The more the generated electricity came from renewables, the lower the CO2 emissions of BEV were than those of internal combustion engine vehicles (ICV) and the Distance of Intersection Point (DIP) comes at a shorter distance

Summary

Introduction

In response to the awareness of human induced climate change in the past decades, the international policy agenda has been driven toward greenhouse gas (GHG) reduction. The transport sector, especially land based passenger transport constitutes the fastest growing source of all GHG emissions. It is recognized as a primary sector [1]. Despite the growing importance of CO2 regulation in the passenger transport sector, the focal point of current regulations is limited only to a vehicle’s operational phase, i.e., tank-to-wheel tailpipe emissions. A prospective unbiased measure to evaluate GHG emissions during a vehicle’s life can be a life-cycle assessment (LCA). This considers the CO2 emissions of vehicles during its operational phase as well as the emissions generated from the fuel extraction, refining, power generation, and its end-of-life phases. LCA studies have gained more attention in recent years as a more holistic view of powertrain solutions for passenger transport with the goal of reducing CO2 emissions

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