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Abstract. The concept of wake steering on wind farms for power maximization has gained significant popularity over the last decade. Recent field trials described in the literature not only demonstrate the real potential of wake steering on commercial wind farms but also show that wake steering does not yet consistently lead to an increase in energy production for all inflow conditions. Moreover, a recent survey among experts shows that validation of the concept currently remains the largest barrier to adoption. In response, this article presents the results of a field experiment investigating wake steering in three-turbine arrays at an onshore wind farm in Italy. This experiment was performed as part of the European CL-Windcon project. While important, this experiment excludes an analysis of the structural loads and focuses solely on the effects of wake steering on power production. The measurements show increases in power production of up to 35 % for two-turbine interactions and up to 16 % for three-turbine interactions. However, losses in power production are seen for various regions of wind directions too. In addition to the gains achieved through wake steering at downstream turbines, more interesting to note is that a significant share in gains is from the upstream turbines, showing an increased power production of the yawed turbine itself compared to baseline operation for some wind directions. Furthermore, the surrogate model, while capturing the general trends of wake interaction, lacks the details necessary to accurately represent the measurements. This article supports the notion that further research is necessary, notably on the topics of wind farm modeling and experiment design, before wake steering will lead to consistent energy gains on commercial wind farms.

Abstract With the rise of awareness of health and well-being in cities, urban environmental analysis should expand from energy performance to new environmental quality-based considerations. The limited potential to annually evaluate outdoor thermal comfort, predominant among these considerations, has restricted the exploration of the interrelations between urban morphology and annual energy performance. This study aims to bridge this gap by capitalizing on the new capabilities of Eddy3D – a Grasshopper plugin which enables effective calculations of hourly microclimatic wind factors via OpenFOAM which in turn are used to generate annual outdoor thermal comfort plots. Using this method, a parametric study was conducted for different typology and density scenarios in three different hot climatic contexts in Israel. The automated analytical workflow evaluated a total of 60 design iterations for their energy balance, outdoor thermal comfort autonomy (OTCA) and self-shading levels using the shade index. The high correlation found here between the annual shade index and the OTCA, across all climatic contexts, shows the potential of the shade index to serve as an effective indicator, in these contexts, for comparative or optimization outdoor comfort studies. Further results are both the superiority of the courtyard typology in both energy and outdoor comfort studies, and the contrasting impact of higher density on the annual energy balance (lower performance) and outdoor thermal comfort (higher performance) in hot climates. The annual plots of both the energy balance and OTCA reveal various seasonal and monthly trends in the three different climatic zones which can lead to localized and seasonal urban design strategies.

As the prospect of exceeding global temperature targets set forth in the Paris Agreement becomes more likely, methods of climate intervention are increasingly being explored. With this increased interest there is a need for an assessment process to understand the range of impacts across different scenarios against a set of performance goals in order to support policy decisions. The methodology and tools developed for Performance Assessment (PA) for nuclear waste repositories shares many similarities with the needs and requirements for a framework for climate intervention. Using PA, we outline and test an evaluation framework for climate intervention, called Performance Assessment for Climate Intervention (PACI) with a focus on Stratospheric Aerosol Injection (SAI). We define a set of key technical components for the example PACI framework which include identifying performance goals, the extent of the system, and identifying which features, events, and processes are relevant and impactful to calculating model output for the system given the performance goals. Having identified a set of performance goals, the performance of the system, including uncertainty, can then be evaluated against these goals. Using the Geoengineering Large Ensemble (GLENS) scenario, we develop a set of performance goals for monthly temperature, precipitation, drought index, soil water, solar flux, and surface runoff. The assessment assumes that targets may be framed in the context of risk-risk via a risk ratio, or the ratio of the risk of exceeding the performance goal for the SAI scenario against the risk of exceeding the performance goal for the emissions scenario. From regional responses, across multiple climate variables, it is then possible to assess which pathway carries lower risk relative to the goals. The assessment is not comprehensive but rather a demonstration of the evaluation of an SAI scenario. Future work is needed to develop a more complete assessment that would provide additional simulations to cover parametric and aleatory uncertainty and enable a deeper understanding of impacts, informed scenario selection, and allow further refinements to the approach.

Introduction: During the COVID-19 lockdown significant improvements in urban air quality were detected due to the absence of motorized vehicles. It is crucial to perpetuate such improvements to maintain and improve public health simultaneously. Therefore, this exploratory study approached bicycle infrastructure in the case of Munich (Germany) to find out which specific bicycle lanes meet the demands of its users, how such infrastructure looks like, and which characteristics are potentially important. Methods: To identify patterns of bicycle infrastructure in Munich exploratory data is collected over the timespan of three consecutive weeks in August by a bicycle rider at different times of the day. We measure position, time, velocity, pulse, level of sound, temperature and humidity. In the next step, we qualitatively identified different segments and applied a cluster analysis to quantitatively describe those segments regarding the measured factors. The data allows us to identify which bicycle lanes have a particular set of measurements, indicating a favorable construction for bike riders. Results: In the exploratory dataset, five relevant segment clusters are identified: viscous, slow, inconsistent, accelerating, and best-performance. The segments that are identified as best-performance enable bicycle riders to travel efficiently and safely at amenable distances in urban areas. They are characterized by their width, little to no interaction with motorized traffic as well as pedestrians, and effective traffic light control. Discussion: We propose two levels of discussion: (1) revolves around what kind of bicycles lanes from the case study can help to increase bicycle usage in urban areas, while simultaneously improving public health and mitigating climate change challenges and (2) discussing the possibilities, limitations and necessary improvements of this kind of exploratory methodology.

The current energy transition imposes a rapid implementation of energy storage systems with high energy density and eminent regeneration and cycling efficiency. Metal hydrides are potential candidates for generalized energy storage, when coupled with fuel cell units and/or batteries. An overview of ongoing research is reported and discussed in this review work on the light of application as hydrogen and heat storage matrices, as well as thin films for hydrogen optical sensors. These include a selection of single-metal hydrides, Ti-V(Fe) based intermetallics, multi-principal element alloys (high-entropy alloys), and a series of novel synthetically accessible metal borohydrides. Metal hydride materials can be as well of important usefulness for MH-based electrodes with high capacity (e.g. MgH2 ~ 2000 mAh g-1) and solid-state electrolytes displaying high ionic conductivity suitable, respectively, for Li-ion and Li/Mg battery technologies. To boost further research and development directions some characterization techniques dedicated to the study of M-H interactions, their equilibrium reactions, and additional quantification of hydrogen concentration in thin film and bulk hydrides are presented at the end of this manuscript.

Los nuevos sistemas inteligentes para ayudar a la transición energética y mejorar la sostenibilidad y la vida de las personas se pueden implementar a diferentes escalas, desde una casa hasta una región entera. Los campus universitarios son un tamaño intermedio interesante (lo suficientemente grande como para importar y lo suficientemente pequeño como para ser manejable) para la investigación, el desarrollo, las pruebas y la capacitación sobre la integración de la inteligencia en todos los niveles, lo que llevó a la aparición del concepto de "campus inteligente" en los últimos años. Este artículo de revisión propone un amplio análisis de la literatura científica sobre campus inteligentes de la última década (2010-2020). Las 182 publicaciones seleccionadas se distribuyen en siete categorías de inteligencia: edificio inteligente, entorno inteligente, movilidad inteligente, vida inteligente, personas inteligentes, gobierno inteligente y datos inteligentes. Las principales preguntas y desafíos abiertos con respecto a los campus inteligentes se presentan al final de la revisión y abordan la sostenibilidad y la transición energética, la aceptabilidad y la ética, los modelos de aprendizaje, las políticas de datos abiertos y la interoperabilidad. El presente trabajo se realizó en el marco de la Red de Energía de la Cumbre de Líderes Regionales (RLS-Energy) como parte de sus esfuerzos de investigación multilateral sobre regiones inteligentes. De nouveaux systèmes intelligents pour aider à la transition énergétique et améliorer la durabilité et la vie des gens peuvent être déployés à différentes échelles, allant d'une maison à une région entière. Les campus universitaires sont une taille intermédiaire intéressante (assez grande pour compter et assez petite pour être maniable) pour la recherche, le développement, les tests et la formation sur l'intégration de l'intelligence à tous les niveaux, ce qui a conduit à l'émergence du concept de « campus intelligent » au cours des dernières années. Cet article de synthèse propose une analyse approfondie de la littérature scientifique sur les campus intelligents de la dernière décennie (2010-2020). Les 182 publications sélectionnées sont réparties en sept catégories d'intelligence : smart building, smart environment, smart mobility, smart living, smart people, smart governance et smart data. Les principales questions et défis ouverts concernant les campus intelligents sont présentés à la fin de l'examen et traitent de la durabilité et de la transition énergétique, de l'acceptabilité et de l'éthique, des modèles d'apprentissage, des politiques de données ouvertes et de l'interopérabilité. Le présent travail a été réalisé dans le cadre du Réseau de l'énergie du Sommet des dirigeants régionaux (RLS-Energy) dans le cadre de ses efforts multilatéraux de recherche sur les régions intelligentes. Novel intelligent systems to assist the energy transition and improve sustainability and people's life can be deployed at different scales, ranging from a house to an entire region. University campuses are an interesting intermediate size (big enough to matter and small enough to be tractable) for research, development, test and training on the integration of smartness at all levels, which led to the emergence of the concept of "smart campus" over the last few years. This review article proposes an extensive analysis of the scientific literature on smart campuses from the last decade (2010-2020). The 182 selected publications are distributed into seven categories of smartness: smart building, smart environment, smart mobility, smart living, smart people, smart governance and smart data. The main open questions and challenges regarding smart campuses are presented at the end of the review and deal with sustainability and energy transition, acceptability and ethics, learning models, open data policies and interoperability. The present work was carried out within the framework of the Energy Network of the Regional Leaders Summit (RLS-Energy) as part of its multilateral research efforts on smart regions. يمكن نشر أنظمة ذكية جديدة للمساعدة في انتقال الطاقة وتحسين الاستدامة وحياة الناس على مستويات مختلفة، تتراوح من منزل إلى منطقة بأكملها. تعتبر الجامعات ذات حجم متوسط مثير للاهتمام (كبيرة بما يكفي لتكون مهمة وصغيرة بما يكفي لتكون قابلة للتتبع) للبحث والتطوير والاختبار والتدريب على تكامل الذكاء على جميع المستويات، مما أدى إلى ظهور مفهوم "الحرم الجامعي الذكي" على مدى السنوات القليلة الماضية. تقترح مقالة المراجعة هذه تحليلاً شاملاً للأدبيات العلمية حول الجامعات الذكية من العقد الماضي (2010-2020). يتم توزيع المنشورات الـ 182 المختارة على سبع فئات من الذكاء: البناء الذكي، والبيئة الذكية، والتنقل الذكي، والمعيشة الذكية، والأشخاص الأذكياء، والحوكمة الذكية، والبيانات الذكية. يتم تقديم الأسئلة والتحديات الرئيسية المفتوحة المتعلقة بالحرم الجامعي الذكي في نهاية المراجعة والتعامل مع الاستدامة وانتقال الطاقة والقبول والأخلاقيات ونماذج التعلم وسياسات البيانات المفتوحة وقابلية التشغيل البيني. تم تنفيذ العمل الحالي في إطار شبكة الطاقة التابعة لقمة القادة الإقليميين (RLS - Energy) كجزء من جهودها البحثية متعددة الأطراف حول المناطق الذكية.