| dc.description.abstract | In the coming decades the society will shift towards less carbon intensive activities, with the goal of reducing the CO2 emissions, and hence mitigate the climate change phenomena. In 2010 the road tranport accounted for 10% of the total greenhouse gases emissions. Since in 2050 the number of light duty vehicles on the roads is expected to reach 2 billion units, from the current 700 million, the transport sector plays a key role in the decarbonization of our society.
Alternative vehicles, such as fuel cells or battery electric vehicles are promoted as future technologies for replacing internal combustion engine vehicles. Although several studies highlight the potential reduction of the impacts from the use phase, where no tailpipe emissions occur, few studies assess with consistency the environmental burden related to the production phase. Furthermore, in the literature, the vehicles assessed belong the C-segment, which is a mid-sized vehicle. However, both bigger and smaller vehicles are produced, and to tackle effectively the emissions due to the production of vehicles, their assessment is needed.
This thesis aimed to build three scalable life cycle inventories for assessing the environmental impacts stemming from the production phase of both conventional and alternative vehicles and technologies. The first inventory, models either the glider for a generic vehicle or a full internal combustion engine vehicle. The segments included in this inventory span from the A-Segment (mini cars) to the F-Segment (full-size luxury car), with 17 gasoline and 21 diesel engines available, plus 3 transmissions. The second inventory, based on data provided by a manufacturer, can be used for the
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impact assessment due to the production of Li-ion batteries with a capacity ranging from 1 to 100 kWh, and the three most used intercalation materials; LiNiCoMgO2 (or NCM), LiNiCoAlO2 (or NCA), and LiFePO4 (or LFP). Finally, the third inventory models a fuel cell system with a net power output ranging from 1 to 150 kW.
The life cycle impact assessments for the global warming potential show that the inventory for an internal combustion engine vehicle is well aligned with the literature and the emissions declared by vehicles manufacturers. Regarding battery electric vehicles and the Li-ion batteries, the results highlight some uncertainty surrounding these studies, where a wider distribution of results is found from both the literature and the manufacturers reports. These uncertainties also characterize the results for a fuel cell system and fuel cell electric vehicle, where no primary data is available, and no studies were performed by industries.
However, the models are based on robust data and assumptions, thus giving high confidence for the impact assessment. Furthermore, the models can be either used singularly, allowing for a precise and comprehensive impact assessment for the single components, or combined together for the analysis of an entire fleet of vehicles comprising several sizes and technologies. | |
