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Item type:Publication, Access status: with files , Green batteries for clean skies: Sustainability assessment of lithium-sulfur all-solid-state batteries for electric aircraft(Wiley-Blackwell, 2023-06); ; ; ; The use of novel battery technologies in short-haul electric aircraft can support the aviation sector in achieving its goals for a sustainable development. However, the production of the batteries is often associated with adverse environmental and socio-economic impacts, potentially leading to burden shifting. Therefore, this paper investigates alternative technologies for lithium–sulfur all-solid-state batteries (LiS-ASSBs) in terms of their contribution to the sustainable development goals (SDGs). We propose a new approach that builds on life cycle sustainability assessment and links the relevant impact categories to the related SDGs. The approach is applied to analyze four LiS-ASSB configurations with different solid electrolytes, designed for maximum specific energy using an electrochemical model. They are compared to a lithium–sulfur battery with a liquid electrolyte as a benchmark. The results of our cradle-to-gate analysis reveal that the new LiS-ASSB technologies generally have a positive contribution to SDG achievement. However, the battery configuration with the best technical characteristics is not the most promising in terms of SDG achievement. Especially variations from the technically optimal cathode thickness can improve the SDG contribution. A sensitivity analysis shows that the results are rather robust against the weighting factors within the SDG quantification method.Publicationtype: Journal ArticleScopus© Citations 12 113 289 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Maintenance, repair, and overhaul of aircraft with novel propulsion concepts : analysis of environmental and economic impacts(Elsevier, 2023); ; ; ; Technological transitions of aircraft propulsion concepts are a key strategy for reducing the environmental impacts of air travel. Using battery-electric and fuel cell-based powertrains can avoid climate-damaging CO2 and non-CO2 emissions from kerosene combustion in conventional jet engines. However, the long service life of aircraft requires extensive maintenance, repair, and overhaul (MRO) processes of the powertrain. The main components of novel powertrain concepts (e.g., batteries, fuel cells, and electric motors) might require more frequent replacements than conventional powertrain components, leading to negative impacts on sustainability. Therefore, this article analyzes the environmental and economic impacts of novel powertrain concepts associated with their MRO. For this purpose, the aging behavior of the main components is analyzed, and replacement times are determined. Using life cycle assessment and life cycle costing, the MRO-related impacts of novel powertrain concepts are investigated and compared to those of conventional jet engines. The analysis shows that batteries, fuel cells, and electric motors must be replaced more often than conventional jet engines. In addition, the replacement frequency of batteries and fuel cells results in higher environmental impacts than conventional jet engines.Publicationtype: Journal ArticleScopus© Citations 3 62 127 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Model-based assessment of the environmental impacts of fuel cell systems designed for eVTOLsHydrogen fuel cells have increasingly gained relevance for electric vertical take-off and landing aircraft due to their potential to overcome the main challenges related to batteries. Previous studies have investigated their feasibility for urban air mobility; however, a robust assessment of their environmental implications is still lacking. To fill this gap, this study follows a model-based life cycle engineering approach to quantify the environmental impacts of a fuel cell system designed for three ranges. The production burdens distributed along the lifetime are demonstrated, showing that, for the best case scenario, 70g CO2-eq. per passenger-kilometer is achieved. Under the premise of green hydrogen production, the stack is the main contributor to the environmental impacts. This changes for non-renewable hydrogen production pathways, where hydrogen has the highest impact contributions. Better environmental performance results from short design ranges; however, systems designed for longer ranges will likely increase attractiveness in the future.Publicationtype: Journal Article96 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparison of conventional and electric passenger aircraft for short-haul flights : a life cycle sustainability assessment(Elsevier, 2022-04); ; ; ; Due to the increasing demand for flights, the aviation sector will become one of the main emitters of harmful emissions such as carbon dioxide (CO2) and nitrogen oxides (NOx) in the long term. Especially short-haul flights are particularly critical because of the high kerosene consumption per passenger kilometer traveled. To counteract this development, the Flightpath 2050 strategy aims to reduce CO2emissions by 75% and NOxemissions by 90% until 2050. To achieve these ambitious reduction goals, radical technological transitions are required. A promising strategy for short-haul flights is the deployment of battery-electric powertrains, which replace conventional jet engines. In addition, sustainable aviation fuels (SAFs) can replace fossil kerosene as energy carriers without changing the powertrain configuration and offer further reduction potentials. However, both solutions can be associated with negative environmental and socio-economic impacts along the life cycle. Therefore, this article aims to analyze the potentials of powertrain transition and alternative energy carriers to make the air transport system more sustainable. A well-to-wake life cycle sustainability assessment is conducted to analyze the environmental and socio-economic impacts of an electric powertrain and SAFs compared to a conventional powertrain powered by fossil kerosene. The assessment results indicate that especially the electric powertrain offers huge reduction potentials. Besides, the results also show that SAFs can reduce the environmental impacts of conventional aircraft in the short term. Therefore, both solutions will be required to achieve the short- and long-term reduction goals of Flightpath 2050.Publicationtype: Journal ArticleScopus© Citations 7 60 254 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Life Cycle Engineering Modelling Framework for batteries powering electric aircrafts : the contribution of eVTOLs towards a more sustainable urban mobility(Elsevier, 2022-04); ; ; ; The aviation industry is increasingly facing the challenge posed by climate change. Alongside the aviation sector, advances in aircraft design and electric propulsion towards sustainability have also emerged in new segments of transportation, the urban air mobility, which has arisen to address the road traffic congestion challenges particularly faced in megacities. Within this new mode of mobility, electric vertical takeoff and landing aircrafts (eVTOLs) have gained interest as a solution for on-demand services, including passenger, cargo transportation, as well as rescue and air ambulances. In this regard, batteries are seen as one of the essential technologies towards decarbonizing the mobility sector. Even though studies have indicated the potential of eVTOLs to enable longer travel distances with significant time savings in comparison with battery electric vehicles (BEVs), the variability in terms of spatial, temporal and technological aspects needs to be addressed in order to assess in how far battery-powered eVTOLs will in fact contribute to a more sustainable urban mobility. Based on a modelling framework of the Life Cycle Engineering (LCE) of future aircraft technologies, this paper investigates the factors contributing to the variability of the environmental assessment results, revealing the inherent complexities of modelling emerging technologies. By simulating different scenarios for the battery operation in eVTOLs and BEVs around the world, a case study demostrates the applicability of the LCE framework in urban and regional application contexts.Publicationtype: Journal ArticleScopus© Citations 4 71 269 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Life cycle sustainability assessment of potential battery systems for electric aircraft(Elsevier, 2021-03); ; ; ; The Flightpath 2050 strategy sets ambitious goals for aviation to reduce its environmental impacts. Therefore, new propulsion concepts that avoid in-flight emissions are being developed. Particular attention is given to (hybrid) electric propulsion systems based on batteries, fuel cells, and synthetic fuels that replace the conventional jet engines. This paper assesses the environmental, economic, and social impacts of eight potential battery systems for short-range aircraft from a life cycle perspective and conducts a pre-selection of suitable technologies. The results indicate that lithium-sulfur batteries are advantageous compared to lithium-ion batteries in terms of environmental as well as social and economic impacts.Publicationtype: Journal ArticleScopus© Citations 17 57 146 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Sustainability assessment and engineering of emerging aircraft technologies - challenges, methods and tools(Multidisciplinary Digital Publishing Institute (MDPI), 2020-07-20); ; ; ; Driven by concerns regarding the sustainability of aviation and the continued growth of air traffic, increasing interest is given to emerging aircraft technologies. Although new technologies, such as battery-electric propulsion systems, have the potential to minimise in-flight emissions and noise, environmental burdens are possibly shifted to other stages of the aircraft's life cycle, and new socio-economic challenges may arise. Therefore, a life-cycle-oriented sustainability assessment is required to identify these hotspots and problem shifts and to derive recommendations for action for aircraft development at an early stage. This paper proposes a framework for the modelling and assessment of future aircraft technologies and provides an overview of the challenges and available methods and tools in this field. A structured search and screening process is used to determine which aspects of the proposed framework are already addressed in the scientific literature and in which areas research is still needed. For this purpose, a total of 66 related articles are identified and systematically analysed. Firstly, an overview of statistics of papers dealing with life-cycle-oriented analysis of conventional and emerging aircraft propulsion systems is given, classifying them according to the technologies considered, the sustainability dimensions and indicators investigated, and the assessment methods applied. Secondly, a detailed analysis of the articles is conducted to derive answers to the defined research questions. It illustrates that the assessment of environmental aspects of alternative fuels is a dominating research theme, while novel approaches that integrate socio-economic aspects and broaden the scope to battery-powered, fuel-cell-based, or hybrid-electric aircraft are emerging. It also provides insights by what extent future aviation technologies can contribute to more sustainable and energy-efficient aviation. The findings underline the need to harmonise existing methods into an integrated modelling and assessment approach that considers the specifics of upcoming technological developments in aviation.Publicationtype: Journal Article59 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Socio-economic life cycle assessment of future aircraft systems(Elsevier, 2020); ; ; ; The development of novel aircraft based on electric propulsion is a key strategy to achieve emission reductions in the aviation sector despite the continuously growing demand for air travel. Most sustainability assessments of aircraft focus on environmental indicators and neglect important socio-economic aspects. We address this gap by developing a conceptual framework for the socio-economic sustainability assessment of aircraft with novel propulsion systems. The framework considers the specific requirements for socio-economic sustainability in the aviation sector and builds on established methods such as life cycle costing and social life cycle assessment to complement the environmental perspective in sustainability assessments.Publicationtype: Journal ArticleScopus© Citations 11 37 123 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Life cycle engineering of future aircraft systems : the case of eVTOL vehicles(Elsevier, 2020); ; ; ; This paper introduces the first steps towards a general modelling framework for the integrated life cycle engineering (LCE) of future air transportation systems. The focus of analysis lies on the potential environmental implications of batteries powering electric vertical takeoff and landing aircrafts (eVTOLs), which have emerged as an option for urban air mobility to alleviate automobile traffic in cities. The impact of main influencing factors on the sustainability of eVTOLs is discussed, presenting the main modelling requirements for an LCE framework to accompany the transition towards a more sustainable air mobility.Publicationtype: Journal ArticleScopus© Citations 18 80 653