Electric car life cycle assessment based on real-world mileage and the electric conversion scenario

• Published in: The international journal of life cycle assessment Vol. 22; no. 1; pp. 15 - 30
• Main Authors: Helmers, Eckard, Dietz, Johannes, Hartard, Susanne
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2017; Springer Nature B.V
• Subjects: Assessing and Managing Life Cycles of Electric Vehicles; Automobiles; Automotive engineering; Batteries; Carbon dioxide; Combustion; Conversion; Driving conditions; Earth and Environmental Science; Electric vehicles; Electricity; Energy consumption; Engines; Environment; Environmental Chemistry; Environmental Economics; Environmental Engineering/Biotechnology; Environmental impact; Life cycle analysis; Life cycle assessment; Life cycles; Sensitivity analysis; Stockpiling; Urban areas; China, People's Rep; Real-world driving; BEV; ICEV; LCA; Electric conversion; Battery electric vehicle; Urban use
• ISSN: 0948-3349; 1614-7502
• DOI: 10.1007/s11367-015-0934-3

Purpose
While almost all life cycle assessment (LCA) studies published so far are based on generic vehicles, type approval energy consumption as well as emission data, and application scenarios related to standardized laboratory-based driving cycles, this projects aims at quantifying the LCA based on a real-world vehicle composition and energy consumption data measured before and after the electric conversion of a mini class car. Furthermore, consequences of a second life of a vehicle’s glider on the environmental impact were investigated.
Methods
After having driven 100,000 km, a Smart was converted from combustion to electric in a laboratory project. The inventory was developed grounded upon materials data from laboratory measurements during the conversion process as well as on real-world energy consumption data prior and after the conversion. Three base models are compared in this life cycle impact assessment: a conventional new Smart (combustion engine), a new electric Smart, and a Smart converted from combustion engine to electric. Together with two sensitivity analyses (four different electricity mixes as well as urban vs. mixed driving conditions) and two EOL treatments, 36 scenarios have been quantified. The inventory is based on Ecoinvent database v 2.2 as a background system and includes raw material extraction.
Results and discussion
In urban use, the modeled battery electric vehicle has a favorable environmental impact compared to the ICEV even when charged with the German electricity mix of the year 2013. The advantage in summed up endpoints of the converted Smart is 23 % vs. the new electric Smart on average for the mixed driving conditions and 26 % for the urban driving conditions, respectively. Over a variety of impact categories, electricity consumption during battery cell production in China as well as impacts due to microelectronic components dominated the life cycle. Results for 18 midpoint categories, endpoints for damages to human health, to resource quality and to ecosystem quality as well as the Single score endpoints are reported.
Conclusions
This investigation points out that real-world treatments in inventory development can more specifically outline the environmental advantages of the electric car. The electric conversion of a used combustion engine vehicle can save an additional 16 % (CO
2
-eq) and 19 % (single score endpoints) of the environmental impact over a lifetime, respectively, when compared with the new BEV.