Direct Air Capture (DAC) in Germany : resource implications of a possible rollout in 2045

Direct Air Capture (DAC) is increasingly being discussed as a possibility to limit climate change. In this study, a possible rollout of the DAC technology at German coastal areas is analysed based on an existing climate neutrality scenario. For the year 2045 the resulting costs as well as land, water and energy consumption are examined. It is concluded that a realization of the DAC technology in Germany might be possible from a technical point of view. However, there is a high demand for land and energy. Since a rollout is needed to start in 20 years at the latest, the required discussion and evaluation should be initiated as quickly as possible

Holistic evaluation of aircraft detection lighting systems for wind turbines in Germany using a multi-method evaluation framework

Transponder-based Aircraft Detection Lighting Systems (ADLS) are increasingly used in wind turbines to limit beacon operation times, reduce light emissions, and increase wind energy acceptance. The systems use digital technologies such as receivers of digital transponder signals, LTE/5G, and other information and communication technology. The use of ADLS will be mandatory in Germany both for new and existing wind turbines with a height of >100 m from 2023 (onshore) and 2024 (offshore), so a nationwide rollout is expected to start during 2022. To fully realize the benefits while avoiding risks and bottlenecks, a thorough and holistic understanding of the efforts required and the impacts caused along the life cycle of an ADLS is essential. Therefore, this study presents the first multi-aspect holistic evaluation of an ADLS. A framework for evaluating digital applications in the energy sector, previously developed by the authors, is refined and applied. The framework is based on multi-criteria analysis (MCA), life cycle assessment (LCA), and expert interviews. On an aggregated level, the MCA results show an overall positive impact from all stakeholders’ perspectives. Most positive impacts are found in the society and politics category, while most negative impacts are of technical nature. The LCA of the ADLS reveals a slightly negative impact, but this impact is negligible when compared to the total life cycle impact of the wind turbines of which the ADLS is a part. Besides the aggregated evaluation, detailed information on potential implementation risks, bottlenecks, and levers for life cycle improvement are presented. In particular, the worldwide scarcity of the required semiconductors, in combination with the general lack of technicians in Germany, lead to the authors’ recommendation for a limited prolongation of the planned rollout period. This period should be used by decision-makers to ensure the availability of technical components and installation capacities. A pooling of ADLS installations in larger regions could improve plannability for manufacturers and installers. Furthermore, an ADLS implementation in other countries could be supported by an early holistic evaluation using the presented framework

An extension of assumed stress finite elements to a general hyperelastic framework

Assumed stress finite elements are known for their extraordinary good performance in the framework of linear elasticity. In this contribution we propose a mixed variational formulation of the Hellinger–Reissner type for hyperelasticity. A family of hexahedral shaped elements is considered with a classical trilinear interpolation of the displacements and different piecewise discontinuous interpolation schemes for the stresses. The performance and stability of the new elements are investigated and demonstrated by the analysis of several benchmark problems. In addition the results are compared to well known enhanced assumed strain elements. © 2019, The Author(s)

Self-grading of students

Nach Darstellung der verschiedenen pädagogischen Zielvorstellungen, mit denen Schülerselbstbeurteilung befürwortet wird (z.B. Angstverminderung oder Entwicklung eigenverantwortlicher Lernstrategien), wird anhand von Untersuchungsergebnissen gezeigt, daß die globale Schülerselbstzensierung stark mit der Zensur des Lehrers übereinstimmen kann. Für einen Teilbereich der Schülerselbstbeurteilung, nämlich für die Auswertung von einfachen „Lernkontrollen“, werden die Bedingungen einer richtigen Auswertung genauer behandelt. Insbesondere wird die Auswertungsbereitschaft analysiert, und zwar vor allem, indem Ergebnisse der „Mogelforschung“ auf der Grundlage der „Erwartungs-Wert-Theorie“ interpretiert werden. (DIPF/Orig.)The author discusses the various pedagogical arguments in support of self-grading and demonstrates by research data that a global self-evaluation of students in some cases does correspond to the teacher’s grading. The conditions under which a correct self-evaluation might take place are discussed in more detail, especially in the light of research on cheating

Implementation factors for green hydrogen projects : a systematic literature review

The global transition to a low-carbon economy relies on the large-scale deployment of green hydrogen as a clean energy carrier and industrial feedstock. Despite numerous project announcements worldwide, actual implementation remains limited. Accordingly, it is necessary to systematically analyse the critical factors influencing the practical deployment of green hydrogen projects. To this end, the paper conducts a systematic literature review examining the factors that determine green hydrogen project implementation success, analyzing 153 academic publications and key reports from IRENA and IEA. The systematic literature review identifies that the implementation of green hydrogen projects hinges on a complex interplay of techno-economic, site-specific resource, economic, and socio-political factors. Notably, there are significant global disparities, which are particularly evident for developing and least developed economies, often relying on international financing, technology transfer, and strategic partnerships. These disparities are also reflected in the academic landscape, where research predominantly focuses on advanced economies and major emerging markets

Conceptualisation of the potential renewables pull effect : a result of topic area 3 "scenarios and transformation pathways" of the research project SCI4climate.NRW

This report was prepared by the Wuppertal Institute in cooperation with the German Economic Institute as part of the SCI4climate.NRW project. The report aims to shed light on the possible phenomenon that the availability and costs of "green" energy sources may become a relevant location factor for basic materials produced in a climate-neutral manner in the future. For this purpose, we introduce the term "Renewables Pull". We define Renewables Pull as the initially hypothetical phenomenon of a shift of industrial production from one region to another as a result of different marginal costs of renewable energies (or of secondary energy sources or feedstocks based on renewable energies). Shifts in industrial production in the sense of Renewables Pull can in principle be caused by differences in the stringency of climate policies in different countries, as in the case of Carbon Leakage. Unlike Carbon Leakage, however, Renewables Pull can also occur if similarly ambitious climate policies are implemented in different countries. This is because Renewables Pull is primarily determined by differences in the costs and availability of renewable energies. In addition, Renewables Pull can also be triggered by cost reductions of renewable energies and by changing preferences on the demand side towards climate-friendly products. Another important difference to Carbon Leakage is that the Renewables Pull effect does not necessarily counteract climate policy. Similar to Carbon Leakage, it is to be expected that Renewables Pull could become relevant primarily for very energy-intensive products in basic materials industries. In these sectors (e.g. in the steel or chemical industry), there is also the possibility that relocations of specific energy-intensive parts of the production process could trigger domino effects. As a result, large parts of the value chains previously existing in a country or region could also be subjected to an (indirect) Renewables Pull effect. For the federal state of NRW, in which the basic materials industry plays an important role, the possible emergence of Renewables Pull is associated with significant challenges as climate policy in Germany, the EU and also worldwide is expected to become more ambitious in the future. This report aims to enable and initiate a deeper analysis of the potential future developments and challenges associated with the Renewables Pull effect. Thus, in the final chapter of the report, several research questions are formulated that can be answered in the further course of the SCI4climate.NRW project as well as in other research projects