Towards Standardized Grid Emission Factors: Methodological Insights and Best Practices

Inconsistent calculation of grid emission factors (EF) can result in widely divergent corporate greenhouse gas (GHG) emissions reports. We dissect this issue through a comprehensive literature review, identifying nine key aspects - each with two to six methodological choices - that substantially influence the reported EF. These choices lead to relative effect variations ranging from 1.9% to 60.9%. Using Germany's 2018-2021 data as a case study, our method yields results that largely align with prior studies, yet reveal relative effects from 0.2% to 94.1%. This study is the first to methodically unpack the key determinants of grid EF, quantify their impacts, and offer clear guidelines for their application in corporate GHG accounting. Our findings hold implications for practitioners, data publishers, researchers, and guideline-making organizations. By openly sharing our data and calculations, we invite replication, scrutiny, and further research.Comment: 25 pages main paper, 67 pages supplementary information, graphical abstract on the very last page (p. 93). Code: https://doi.org/10.24355/dbbs.084-202309131139-0, Data: https://doi.org/10.24355/dbbs.084-202309111514-

Design of Eco-Efficient Body Parts for Electric Vehicles Considering Life Cycle Environmental Information

The reduction of greenhouse gas (GHG) emissions over the entire life cycle of vehicles has become part of the strategic objectives in automotive industry. In this regard, the design of future body parts should be carried out based on information of life cycle GHG emissions. The substitution of steel towards lightweight materials is a major trend, with the industry undergoing a fundamental shift towards the introduction of electric vehicles (EV). The present research aims to support the conceptual design of body parts with a combined perspective on mechanical performance and life cycle GHG emissions. Particular attention is paid to the fact that the GHG impact of EV in the use phase depends on vehicle-specific factors that may not be specified at the conceptual design stage of components, such as the market-specific electricity mix used for vehicle charging. A methodology is proposed that combines a simplified numerical design of concept alternatives and an analytic approach estimating life cycle GHG emissions. It is applied to a case study in body part design based on a set of principal geometries and load cases, a range of materials (aluminum, glass and carbon fiber reinforced plastics (GFRP, CFRP) as substitution to a steel reference) and different use stage scenarios of EV. A new engineering chart was developed, which helps design engineers to compare life cycle GHG emissions of lightweight material concepts to the reference. For body shells, the replacement of the steel reference with aluminum or GFRP shows reduced lifecycle GHG emissions for most use phase scenarios. This holds as well for structural parts being designed on torsional stiffness. For structural parts designed on tension/compression or bending stiffness CFRP designs show lowest lifecycle GHG emissions. In all cases, a high share of renewable electricity mix and a short lifetime pose the steel reference in favor. It is argued that a further elaboration of the approach could substantially increase transparency between design choices and life cycle GHG emissions

The influence of stakeholder perspectives on the end-of-life allocation in the life cycle assessment of lithium-ion batteries

With an increasing number of electric vehicles on roads, recycling is an important topic to design circular supply chains for batteries. To stimulate such circular supply chains, the new EU battery directive includes mandatory recycled content in batteries and recovery rates of materials for lithium-ion batteries on the European market. Modeling the end-of-life of batteries as part of a life cycle assessment (LCA) is methodologically challenging as batteries are quite complex product systems. One of these challenges is the allocation of material impacts from different life cycle stages along subsequent product life cycles. We analyzed the different stakeholders in the life cycle of a lithium-ion battery and identified possible LCA questions based on their decision contexts. For each LCA question, an LCA archetype was defined, which includes the functional unit, the system boundary, and the allocation procedure. These archetypes are applied and tested in a case study. The results show a significant variance depending on the archetype used. This highlights the importance of understanding the stakeholder perspective in LCA and decision support

Life-cycle analysis of last-mile parcel delivery using autonomous delivery robots

The acceleration of global e-commerce brings an increasing environmental burden to urban last-mile logistics. Autonomous delivery robots (ADRs) have often been considered as an attractive solution to this challenge but, to date, their environmental impact had not been fully assessed. To fill this gap, a life-cycle analysis of two-echelon and business-as-usual distribution strategies is proposed in this paper. To model ADR production, primary data from an actual prototype is used. The mathematical formulation of the use stage is done using the continuous approximation methodology. Finally, some managerial insights are obtained. Two-echelon operations would generate between 60 and 130 gCO2-eq per parcel delivery depending on the considered operation scenario. The ADR fleet production and renewal are the biggest contributors to this total global warming potential (GWP). As a consequence, the three main leverages to decrease the GWP of an ADR-based two-echelon delivery scheme are an improvement of the ADR production processes, the maximization of the robot lifespan (both for mechanical parts and battery), and the optimization of delivery operations to minimize the robot fleet size.The first author would like to personally acknowledge CARNET for the funding of this research article, developed in the framework of his PhD thesis. The second author also thanks the funding by the DFG, German Research Foundation, under Germany's Excellence Strategy - EXC 2163/1 – SE2A. The participation of the last author of this paper was made under the project PID2020-118641RB-I00, funded by the Spanish Ministry of Science and Innovation, MCIN/AEI/10.13039/501100011033. The authors also acknowledge the comments of anonymous reviewers that greatly helped in improving and clarifying the paper.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

Life cycle assessment of a disposable and a reusable surgery instrument set for spinal fusion surgeries

Producción CientíficaThe worldwide increasing wealth and increased life expectancy of humans has led to an increase in the number of medical procedures and surgeries. Surgeries are complex medical procedures which contribute to a significant share of the total environmental impact of the healthcare system. Among other important sources of environmental impacts from surgeries, material consumption due to required instrumentation accounts for up to 65 % of greenhouse gas emissions from surgeries. This study investigates how a disposable and a reusable surgery instrument sets for lumbar fusion surgeries contribute to the environmental impact and which system is more advantageous for the environment. For lumbar fusion surgeries, reusable and disposable instrumentation and implant sets are commercially available. Both sets are capable to support a one level lumbar fusion surgery. The reusable set is comprehensive and fully opened before the surgery, while the disposable system comes in a modular box system, and the boxes are opened on demand during the surgery. To compare the environmental impact of these different configurations, a comparative Life Cycle Assessment (LCA) was performed to assess the overall environmental impacts of both alternatives. One of the key findings is that the selected cleaning and sterilization process for reusable instruments is responsible for up to 90 % of the greenhouse gas emissions and decides which system is advantageous from an environmental perspective. Reducing the number of instruments to be cleaned and sterilized for a surgery should be the focus for future surgery instruments development from an environmental perspective

Model-based identification of production tolerances in battery production

Battery technology in combination with carbon-free energy presents a major paradigm shift for the future of the mobility and energy storage sector and already creates an immense demand for large scale battery factories. However, current battery production sites still report considerable scrap rates caused by insufficient process control and a lack of adequate production tolerances, which increase the cost and environmental impact of the battery cells. The present work introduces a methodology which assist in defining model-based production tolerances by considering the impact of varying process parameters on final cell properties in combination with production cost and cell revenue

Sustainability Assessment and Engineering of Emerging Aircraft Technologies: Challenges, Methods and Tools

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

Competencia para desarrollar el razonamiento matemático a través de fracciones

Evaluación diagnóstica Tema 1 Tema 2 Tema 3 Tema 4 Tema 5 Evaluación final Créditos Referencia

Green batteries for clean skies: Sustainability assessment of lithium‐sulfur all‐solid‐state batteries for electric aircraft

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

Material reutilization cycles across industries and production lines

The concept of Industrial Symbiosis aims at organizing industrial activity like a living ecosystem where the by-product outputs of one process are used as valuable raw material input for another process. A significant method for the systematic planning of Industrial Symbiosis is found in input–output matching, which is aimed at collecting material input and output data from companies, and using the results to establish links across industries. The collection and classification of data is crucial to the development of synergies in Industrial Symbiosis. Public and private institutions involved in the planning and development of Industrial Symbiosis rely however on manual interpretation of information in the course of creating synergies. Yet, the evaluation and analysis of these data sources on Industrial Symbiosis topics is a tall order. Within this chapter a method is presented which describes value creation activities according to the Value Creation Module (VCM). They are assessed before they are integrated in Value Creation Networks (VCNs), where alternative uses for by-products are proposed by means of iterative input-output matching of selected value creation factors