• Energy Research

Abstract Microgrids integrating local renewable energy sources at low-voltage level show promising potentials in realizing a reliable, efficient, and clean supply of electricity. Further improvements are expected when such a microgrid is operated based on direct current (dc) instead of alternating current (ac) infrastructure for power distribution commonly in use today. Our study aims to systemically quantify the gap between environmental impacts of microgrids at building level using the case study of power distribution within office buildings. For this purpose, a scalable comparative life cycle assessment (LCA) is conducted based on a technical bottom-up analysis of differences between ac and dc microgrids. Particularly, our approach combines the micro-level assessment of required power electronic components with the macro-level requirements for daily operation derived from a generic grid model. The results indicate that the environmental impacts of employed power electronics are substantially reduced by operating a microgrid based on dc power distribution infrastructure. Our sensitivity analyses show that efficient dc microgrids particularly lead to savings in climate change impact emissions. In addition, our study shows that the state-of-the-art scaling rules of power electronics currently used in LCAs leads to inaccurate results. In contrast, the proposed methodology applies a more technical approach, which enables a detailed analysis of the environmental impacts of power electronic components at system level. Thus, it provides the foundation for an evaluation criterion for a comprehensive assessment of technological changes within the framework of energy policy objectives.

The transformation of the energy system is a highly complex process involving many dimensions. Energy system models help to understand the process and to define either target systems or policy measures. Insights derived from the social sciences are not sufficiently represented in energy system models, but address crucial aspects of the transformation process. It is, therefore, necessary to develop approaches to integrate results from social science studies into energy system models. Hence, as a result of an interdisciplinary discourse among energy system modellers, social scientists, psychologists, economists and political scientists, this article explains which aspects should be considered in the models, how the respective results can be collected and which aspects of integration into energy system models are conceivable to provide an overview for other modellers. As a result of the discourse, five facets are examined: Investment behaviour (market acceptance), user behaviour, local acceptance, technology innovation and socio-political acceptance. Finally, an approach is presented that introduces a compound of energy system models (with a focus on the macro and micro-perspective) as well as submodels on technology genesis and socio-political acceptance, which serves to gain a more fundamental knowledge of the transformation process.

Local implementation projects for sector coupling play an important role in the transformation to a more sustainable energy system. Despite various technical possibilities, there are various barriers to the realisation of local projects. Against this backdrop, we introduce an inter- and transdisciplinary approach to identifying and evaluating different power-to-X paths as well as setting up robust local implementation projects, which account for existing drivers and potential hurdles early on. After developing the approach conceptually, we exemplify our elaborations by applying them to a use case in the German city of Wuppertal. It can be shown that a mix of several interlinked interdisciplinary methods as well as several participatory elements is suitable for triggering a collective, local innovation process. However, the timing and extent of end-user integration remain a balancing act. The paper does not focus on a detailed description of power-to-X (PtX) as a central pillar of the sustainable transformation of the energy system. Rather, it focuses on the innovative methodological approach used to select a suitable use path and design a corresponding business model. The research approach was successfully implemented in the specific case study. However, it also becomes clear that the local-specific consideration entails limitations with regard to the transferability of the research design to other spatial contexts.

How dependent are European power systems and economies on natural gas? To answer this pressing question, we coupled a simulation model for assessing security of electricity supply and an economic optimization model. With this, we were able to analyze different reduction scenarios of the amount of gas utilized in the power sector. Our results show that reducing the amount of natural gas in the European power sector by up to 30% has a relatively moderate impact on the security of electricity supply. Restrictions of 40% or more result in substantially higher reductions in electricity demand shortfall and are associated with economic costs of more than EUR 77 billion. Furthermore, we demonstrate that a close coordination of gas distribution on a European level would be instrumental in mitigating negative economic consequences. Finally, it can be deduced that a coordinated delay of planned power plant shutdowns could effectively compensate for reduced gas volumes in the electricity sector.

The JERICHO-E-usage dataset including code for compilation. The dataset includes time series of useful energy consumption patterns for energy system modeling. The time series data covers 38 NUTS2 regions in germany and has an hourly resolution. The dataset distinguished between four sectors - the residential, the industrial, the commerce, and the mobility sectors. Useful energy types comprise space heating, warm water, process heating, space cooling, process cooling, mechanical energy, information and communication technology, and lighting.

In 2011, the concept of Industry 4.0 was introduced and later adopted by the German government, paving the way for a new industrial revolution in Germany. The high significance of this topic is reflected by the large number of corresponding publications. Additionally, the regional focus of research is widespread on a global level and often differs even at a national level. This paper generates transparency regarding the adoption of the concept of Industry 4.0 by analyzing the locations of main contributors within the research field on an international, European, and German-national level. Further, it examines the regionally different foci concerning the concept of Industry 4.0. Having identified four main aspects linked to Industry 4.0 within a pre-study, a quantitative literature research was conducted based on over 800 published papers. The results were further visualized with QGIS. Looking at the results, it can be concluded that the German research community is virtually the only user of the term Industry 4.0, while other institutions seem to link their research to other related concepts. On a German level, the majority of the analyzed studies originate from Southern and Western Germany. North Rhine-Westphalia and the Aachen/Jülich region, in particular, represent main contributors.