This paper summarizes the findings of a detailed assessment of synthetic, electricity-based fuels for use in aviation, shipping, and road transport. The fuels considered correspond to the most promising alternatives that were analyzed as part of the German research project BEniVer (Begleitforschung Energiewende im Verkehr—Accompanying Research for the Energy Transition in Transport) initiated by the German Federal Ministry for Economic Affairs and Climate Action (BMWK). Focusing on usage, infrastructure, and ecological analyses, several e-fuels were evaluated and compared to fossil fuels according to the specific sector. It turns out that for all sectors evaluated, the existing sustainable synthetic fuels are already compatible with current technology and regulations. In shipping and road transport, the use of advanced, sustainable fuels will allow for a more distinct reduction in emissions once technology and regulations are adopted. However, standard-compliant synthetic gasoline and diesel are considered the most promising fuels for use in road transport if the transition to electricity is not realized as quickly as planned. For the aviation sector, the number of sustainable aviation fuels (SAFs) is limited. Here, the current aim is the introduction of a 100% SAF as soon as possible to also tackle non-CO₂ emissions.

This study builds a bridge between the advancements from prospective life cycle assessments (pLCAs) and dynamic life cycle assessments (dLCAs) to improve the evaluation of circular economy (CE) strategies for long-lived products such as energy technologies. Based on a literature review of recent developments from pLCA and dLCA, an extended LCA methodology is proposed that provides guidance in the consideration and integration of technological and market dynamics across all major LCA steps of a dLCA, whose flows and impacts extend over a long period of time. This ensures a more accurate assessment of the impacts on global warming over time by explicitly incorporating temporal differentiation into goals and scopes, life cycle inventories, and interpretations. The methodology was applied to compare two CE measures for wind turbines: full repowering, including material recycling, and partial repowering. The analysis revealed that full repowering is the environmentally preferable option from the perspective of global warming potential, as the higher electricity output offsets the emissions associated with decommissioning and new construction. The findings were robust under various assumptions on future technological advancements, the underlying decarbonization scenario aligned with the Paris Agreement, and the application of discounting of future emissions. Ultimately, this work provides a practical yet adaptable approach for integrating future-oriented LCA methods into decision-making for more sustainable infrastructure and machinery.

The results of life cycle assessments (LCAs) are used for sustainable decision-making. Parameters that impact environmental performance during a product’s lifetime, e.g., operational electricity mix, are subject to future change. Especially in energy technologies with a long lifespan, future developments need to be included early in the tender stage by utilizing prospective LCA. Existing studies of transformers show that the significant global warming potential (GWP) impact results from operational electricity losses. The influence on industrial LCA from considering future developments already in a project’s tender phase is analyzed in this paper by implementing a future German electricity mix for the operation stage of a power transformer. The results show a reduction of 85% in the transformer’s GWP by integration of prospective data from 2030 and 2050 and 90% when prospective data are integrated in 5-year steps until 2050. This reflection of further developments makes product LCA results more accurate and therefore impacts, e.g., reported scope 3 emissions. The increased resolution of a product model allows focusing on parameters that are relevant during a product’s lifetime and developing, e.g., tailor-made circularity measures to improve the product’s environmental performance, thereby supporting sustainable decision-making.

Scope-3-Emissionen sind für einen Großteil der Treibhausgasemissionen von Unternehmen verantwortlich und damit zentral für eine nachhaltige Transformation der Wirtschaft. Dieser Artikel erläutert die Bilanzierung von Scope-3-Emissionen und damit verbundene Chancen, Herausforderungen und Reduktionsmaßnahmen und hilft so bei der Umsetzung der neuen Anforderungen in der Nachhaltigkeitsberichterstattung.