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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.

Abstract Public participation is often part of planning and decision-making processes relating to the German energy transformation (Energiewende). Factors influencing the active involvement of individuals have not been fully investigated, although these factors may impact the outcome of participatory decision making. However, a few concepts are discussed relating to what kind of people participate in governance processes: political efficacy, place attachment, value orientation, and sociodemographic characteristics. We further assumed that the aspects of attitudes toward renewable energy technologies, general knowledge about environment and energy, specific knowledge about electricity-generating technologies, personality strength, and living situation might influence people's participation in planning and decision making related to energy issues. In this study, we examine the relevance of these concepts based on a survey for which (n=) 2400 respondents were recruited from an access panel to build up a quota sample on the three crossed characteristics: gender, age, and school education. Many of the respondents are aware of participation options but very few become actively engaged in participation processes. The multivariate analyses conducted showed that attitudes towards renewable energy technologies, value orientation towards nature, political efficacy, personality strength, and individuals' specific knowledge have a strong influence on whether someone becomes actively involved or not.

AbstractSustainable biorefineries have a critical role to play in our common future. The need to provide more goods using renewable resources, combined with advances in science and technology, has provided a receptive environment for biorefinery systems development. Biorefineries offer the promise of using fewer non‐renewable resources, reducing CO2 emissions, creating new employment, and spurring innovation using clean and efficient technologies. Lessons are being learned from the establishment of first‐generation biofuel operations. The factors that are key to answering the question of biorefinery sustainability include: the type of feedstock, the conversion technologies and their respective conversion and energy efficiencies, the types of products (including coproducts) that are manufactured, and what products are substituted by the bioproducts. The BIOPOL review of eight existing biorefineries indicates that new efficient biorefineries can revitalize existing industries and promote regional development, especially in the R&D area. Establishment can be facilitated if existing facilities are used, if there is at least one product which is immediately marketable, and if supportive policies are in place. Economic, environmental, and social dimensions need to be evaluated in an integrated sustainability assessment. Sustainability principles, criteria, and indicators are emerging for bioenergy, biofuels, and bioproducts. Practical assessment methodologies, including data systems, are critical for both sustainable design and to assure consumers, investors, and governments that they are doing the ‘right thing’ by purchasing a certain bioproduct. If designed using lifecycle thinking, biorefineries can be profitable, socially responsible, and produce goods with less environmental impact than conventional products … and potentially even be restorative!. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd

Xiyu Ren is a DPhil candidate at the Smith School of Enterprise and the Environment, the School of Geography and the Environment, and the Institute for New Economic Thinking at the Oxford Martin School of the University of Oxford. Her research interests lie in energy and environmental economics, particularly in energy modeling, electricity market design, times-series analysis, and environmental policies. Iacopo Savelli is a postdoctoral researcher in applied economics at the GREEN Centre, Bocconi University. He is the PI of the peer-reviewed project “Decarbonising the energy system by incentivising energy storage in the right places,” investigating the role of grid-scale energy storage in decarbonizing the energy system. Previously, he was a postdoc at the University of Edinburgh and the University of Oxford working on energy market design. He holds a PhD in engineering, an MS in finance, and a BS in economics. He taught selected energy economics topics at the University of Oxford and the University of Siena. Thomas Morstyn is associate professor in power systems with the Department of Engineering Science of the University of Oxford, where he leads a research group focused on power system control and energy market design. He is also a tutorial fellow at Hertford College and an honorary fellow at the University of Edinburgh. He is an associate editor of IEEE Transactions on Power Systems and co-chairs the IEEE Power & Energy Society Taskforce on Quantum Computing for Power System Operations. His research focuses on the design of control systems and markets to enable the large-scale integration of distributed power system flexibility.

Climate change will bring warmer and wetter conditions and more frequent extreme events in the Nemoral climate zone. These changes are expected to affect maize growth and yields. In this study, we applied the AgroC model to assess climate change impact on changes in growing environmental conditions, growing season length, yield and potential yield losses due to multiple abiotic stresses. The model was calibrated and validated using data from dedicated field experiments conducted in Lithuania during four meteorologically contrasting years (2015, 2016, 2017 and 2019). We simulated the climate impacts on rainfed maize for long-term future climate conditions from 2020 to 2100 under the RCP2.6 (low), RCP4.5 (medium) and RCP8.5 (high) emission scenarios. As a result, we found that air temperature, sum of growing degree days and amount of precipitation during the growing season of maize will increase, especially under medium and higher emission scenarios (RCP4.5 and RCP8.5), with significantly positive effect on yields. The simulation results showed that average maize grain yield will increase under RCP2.6 by 69 kg ha-1 per decade, under RCP4.5 by 197 kg ha-1 per decade and under RCP8.5 by 304 kg ha-1 per decade. The future potential maize yield reveals a progressive increase with a surplus of +10.2% under RCP4.5 and +14.4% under RCP8.5, while under RCP2.6 the increase of potential yield during the same period will be statistically not significant. The yield gap under RCP2.6 and RCP4.5 will fluctuate within a rather narrow range and under RCP8.5, it will decrease.

Abstract Bioeconomy is deemed to be an ambiguous term with multiple facets: new products from biomass, circular and cascading resource systems, developments of new and more resilient plants, or synthetic biology for molecular biotechnology, to name a few. Accordingly, the term is interpreted just as diversely by involved stakeholders and the broader public. To enable a clear and constructive dialog on bioeconomy strategies with and among society requires a profound understanding of these perceptions. Addressing this issue, a representative survey was conducted among the German population in order to scrutinize the general public's understanding of the term bioeconomy, citizens’ knowledge, fears, and expectations, as well as factors explaining their attitudes toward the bioeconomy. Our results indicate that, so far, German citizens are not very familiar with the concept. Its underlying ideas, however, are vastly appreciated. Support for a sustainable bioeconomy is thus strong and connected to high expectations in terms of environmental and economic benefits, which needs to be taken into account both in the implementation and communication of bioeconomy strategies. Support for the bioeconomy is furthermore connected to beliefs that reflect environmental concern and to pro-environmental behavior. While most measures and principles related to the bioeconomy (e.g., the use of biogas, biofuels, renewable materials for everyday products or buildings, or the cascading and circular use of resources) are strongly appreciated, the use of genetic engineering, for example, is opposed, mainly with regard to its applications in agriculture and industry, to a lesser extent in medicine.

Ammonia is a promising clean and sustainable energy carrier, yet challenges persist in achieving stable combustion, particularly concerning poor ignition quality and elevated NOx emissions. Recent research suggests that the Moderate or Intense Low-oxygen Dilution (MILD) regime could address these challenges for ammonia combustion. This study aims to optimize the MILD regime using non-equilibrium plasma discharges, specifically nanosecond repetitive pulsed discharges (NRPD). While the beneficial effects of NRPD on ammonia chemistry have been demonstrated in traditional applications, their impact under the highly diluted conditions characteristic of the MILD regime remains unexplored. This numerical study employs a detailed two-temperature model to investigate the effects of pulsed discharges in ammonia/air mixtures, simulating conditions representative of the MILD regime. The research comprehensively explores the selection of optimal discharge settings and examines plasma effects on various parameters, including ignition delay time, flammability limit, radical production, and emissions. Equivalence ratios ranging from 0.2 to 2 and dilution levels up to 2.5% O2 are considered in this investigation. Results indicate that NRPD show a notable benefit by enlarging fuel-lean and fuel-rich stability limits, promising enhanced operational flexibility. Examining OH radicals and NOx emissions underscored a consistent plasma-driven mechanism, reducing emissions, also in the MILD regime. Novelty and Significance Statement The novelty of this research is the application of non-equilibrium plasma discharges to improve ammonia combustion in the MILD regime. It offers a new and original solution to the challenges associated with the poor ignition quality and high NOx emissions that are currently limiting its practical implementation. For the first time, a numerical analysis is provided to quantify the benefits of plasma chemistry activation on the combustion performance. Another novel aspect of this work is the use of a detailed two-temperature model to describe the plasma-combustion interactions in an integrated computational framework. The literature reports only a few references on the interaction of plasma with MILD combustion conditions. The former were modeled using a very simplified model to describe the evolution of the plasma species. Consequently, we believe that this contribution will significantly advance the state-of-the-science in field of plasma-assisted ammonia combustion.