Scalable Life-Cycle Inventory for Heavy-Duty Vehicle Production

Abstract

<jats:p>The transportation sector needs to significantly lower greenhouse gas emissions. European manufacturers in particular must develop new vehicles and powertrains to comply with recent regulations and avoid fines for exceeding C O 2 emissions. To answer the question regarding which powertrain concept provides the best option to lower the environmental impacts, it is necessary to evaluate all vehicle life-cycle phases. Different system boundaries and scopes of the current state of science complicate a holistic impact assessment. This paper presents a scaleable life-cycle inventory (LCI) for heavy-duty trucks and powertrains components. We combine primary and secondary data to compile a component-based inventory and apply it to internal combustion engine (ICE), hybrid and battery electric vehicles (BEV). The vehicles are configured with regard to their powertrain topology and the components are scaled according to weight models. The resulting material compositions are modeled with LCA software to obtain global warming potential and primary energy demand. Especially for BEV, decisions in product development strongly influence the vehicle’s environmental impact. Our results show that the lithium-ion battery must be considered the most critical component for electrified powertrain concepts. Furthermore, the results highlight the importance of considering the vehicle production phase.</jats:p>

Comparative Life Cycle Assessment of Propulsion Systems for Heavy-Duty Transport Applications

“…It is clear from this figure that the battery electric truck's (BET) power unit of a Li-ion battery has the highest GWP, producing 7.8-times the emissions of the ICE, and 3.7-times the FC system. This can be compared to S. Wolff's study [25] which yields a range of 52,834.44 kgCO 2 e up to 121,925.63 kgCO 2 e for BET battery production, as they state that battery production can account for between 13 to 30% of total manufacturing GWP [25]. This investigation is on the conservative side of this range with a value of 62,757.37 kgCO 2 e. A key factor in the large GWP is the substantial mass of the battery that is needed to meet the power requirements for a HGV.…”

“…In this case, the FC system is the better option, as the full electric battery system produces close to 4 times the GWP. This can be attributed to the large mass of battery that is required to achieve the desired power outputs for a HGV, with S. Wolff [25] stating the battery can account for 46-56% of the tractor weight. This then has a knock-on effect with the efficiency as when the battery charge reduces the mass does not, unlike the FC and ICE systems where the fuel loads reduce.…”

“…This will be done for each of the power units, meaning that the Cradle-to-Gate section shown within Figure 2 will be satisfied. This is a similar approach to S. Wolff et al's [25] study, but with an emission focus, to ensure the main question of this study is answered.…”

“…The next LCI that needs compiling is for the ICE. The BOM for this was taken from S. Wolff's study [25]. As the ICE used in this study has similar power outputs to what would be expected from the Hyundai XCIENT, no scaling is required and the values in Table 4 can be used.…”

“…As the ICE used in this study has similar power outputs to what would be expected from the Hyundai XCIENT, no scaling is required and the values in Table 4 can be used. S. Wolff's [25] study also states the mass of batteries required for a full electric HGV, and detailing that for a Li-ion battery system to produce the same power outputs as the ICE system a mass of 5265 kg is required. This can then be combined with the percentage breakdown produced by the ANL [21] to gain the scaled BOM in Table 5.…”