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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.

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.

Summary Afforestation projects using species mixtures are expected to better support ecosystem services than monoculture plantations. While grassland studies have shown natural selection favoring high‐performance genotypes in species‐rich communities, this has not been explored in forests. We used seed‐family identity (known maternity) to represent genetic identity and investigated how this affected the biomass accumulation (i.e. growth) of individual trees (n = 13 435) along a species richness gradient (1–16 species) and over stand age (9 yr) in a forest biodiversity experiment. We found that among the eight species tested, different seed families responded differently to species richness, some of them growing relatively better in low‐diversity plots and others in high‐diversity plots. Furthermore, within‐species growth variation increased with species richness and stand age, while between‐species variation decreased with stand age. These results indicate that seed families within species and their reaction norms along the species richness gradient vary considerably and thus can explain a substantial proportion of the overall variation in tree growth. Our findings suggest that the growth and associated ecosystem services of species‐rich mixtures in afforestation projects can be optimized by artificially selecting seed families with high mixture performance in biodiversity experiments.

The demand for energy sources with high energy densities continues to push the limits of Ni-rich layered oxides, which are currently the most promising cathode materials in automobile batteries. Although most current research is focused on extending battery life using Ni-rich layered cathodes, long-term cycling stability using a full cell is yet to be demonstrated. Here, we introduce Li[Ni0.90Co0.09Ta0.01]O2, which exhibits 90% capacity retention after 2,000 cycles at full depth of discharge (DOD) and a cathode energy density >850 Wh kg−1. In contrast, the currently most sought-after Li[Ni0.90Co0.09Al0.01]O2 cathode loses ~40% of its initial capacity within 500 cycles at full DOD. Cycling stability is achieved by radially aligned primary particles with [003] crystallographic texture that effectively dissipate the internal strain occurring in the deeply charged state, while the substitution of Ni3+ with higher valence ions induces ordered occupation of Ni ions in the Li slab and stabilizes the delithiated structure. Nickel-rich layered oxide cathodes are at the forefront of the development of automobile batteries. The authors report an atomic and microstructural engineering design for a Li[Ni0.90Co0.09Ta0.01]O2 cathode that exhibits outstanding long-term cyclability and high energy at full depth of discharge in full cells.

Polymers are essential for long-term green energy production by photovoltaics (PV). We created a unique dataset that links electrical performance data of 28,030 PV modules, combined into 1295 strings and 423 inverters with the identity of the backsheet (BS) materials of each of the tested modules. This dataset gives an insight into BS-versatility and resulting impact on the insulation resistance of strings and inverters. The BSs were analyzed using near infrared absorption spectroscopy (NIRA) plus visual inspection in the field. The insulation resistance (Riso) of selected modules and strings was measured on-site. Furthermore, reported ground impedance (GI) values were evaluated with respect to an inverter-specific threshold below which the inverters do not start operation. We differentiated seven BS-types, the three most frequent being polyamide (PA), fluorinated coating (FC), and polyvinylidene fluoride (PVDF). Although modules with PA show often BS cracking, the insulation resistance was above the threshold. Similar, the GI of inverters with modules with PVDF-BSs was high. Modules with FC-BSs feature generally low Riso–values on module-, string-, and on inverter level. Evaluating historic data reveals an increase in frequency of GI-values below the threshold for inverters connected to modules with exclusively FC-BSs. While inverters with modules having PA- or PVDF-BSs function as expected, inverters with modules having FC-BSs require maintenance to keep power yield on an acceptable level. The dataset collected in the present work highlights that the choice of BS-material of PV-modules is essential for reliable operation of PV power stations.