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AbstractCurrent building regulations enforce building designers towards efficient system design and provision of alternative means of supplying energy. Different green building certification schemes are deployed worldwide to encourage creating a sustainable built environment and the adoption of green building best practices.Micro-generation technologies, low and zero carbon, are either recommended by designers or mandated. A range of constraints including design and technical issues, are currently affecting the wide-scale deployment of micro-generation. For instance, it is important that the micro-generation plant operates for as many hours as possible as an idle plant accrues no benefits. Such issues make the design of a micro-cogeneration technology not quite as straightforward. Combined Heat and Power (CHP) or micro-cogeneration provides means of electricity and heat supply.This paper investigates, through a detailed study, the maximum CO2 reduction that could be achieved by CHP and biomass technologies in a mixed-use development. The implementation of micro-cogeneration, its combination with district heating and the integration of CHP into a trigeneration scheme are investigated. The coupling of CHP unit with absorption cooling, as well as the interactions with biomass boilers, to allow for setting up multi-generation systems for combined local production of different energy vectors are assessed and optimised for maximum CO2 reduction.

This study has developed a methodology for the nexus approach by integrating interdisciplinary and transdisciplinary concepts and qualitative and quantitative mixed methods into the process of the systems thinking approach. The nexus approach was institutionalized in two projects using the location specific case study of Beppu, Japan where a set of interconnected issues in using geothermal hot spring resources have emerged due to the promotion of geothermal energy development under low-carbon policies at global and national levels. The interlinkages among geothermal hot spring resources, including heat, steam, nutrients, and drainage between land and coastal systems were analyzed to improve decision- and policy-making. This study discusses (1) how different discipline-oriented methods and data are integrated, (2) how much of the targeted water-energy-food nexus systems are understood using the nexus approach, and (3) how far does the nexus approach influence changes in the policy agenda and human behavior regarding sustainable geothermal hot spring resources use. The nexus approach facilitated the sequential integration of individual methods and data to better explain the causal linkages focusing on water-energy-food resources in the human-nature systems in Beppu. The proposed policy recommendations are based on the local government initiative for continuing to conduct citizen participatory surveys on geothermal hot spring resources. Transferring the developed methodology will help to effectively develop geothermal hot spring resources and compliment the current national renewable energy and natural resource policies and management.

Methane emissions from reindeer (Rangifer tarandus tarandus) fed lichens (mainly Cladonia stellaris) and a concentrate feed were determined using open-circuit respirometry. The lichen diet was low in crude protein ( 4 weeks prior to experiments and methane emissions recorded for two separate 23 h periods for each diet. Methane emissions increased on average by 0.93 g/h (or by 5.8 times) in the first hour after feeding the concentrate feed, while emissions remained unchanged after the intake of lichens. Mean methane emissions from reindeer (n = 5) were 7.5 ± 0.54 (SE) g CH4 day−1 when fed lichens, compared to a higher emission (p = 0.001) of 11.2 ± 0.54 g CH4 day−1 on the concentrate diet. The mean proportion of gross energy intake lost as methane was 5.2 ± 0.37% on the lichens and 7.6 ± 0.37%, or some 50% higher, on the concentrate feed. This difference was significant (p < 0.001). Our results suggest that it is of environmental importance to preserve the lichens on the tundra and minimize supplementary feeding with concentrate diets, in order to reduce methane emission.

Urban communities differ in their social, economic, and environmental characteristics, as well as in the approach to energy use. Dynamic energy use and available on-site resources allow interaction with the surroundings and contribute to the key performance indicators of smart cities. This study aimed at proposing systematically a strategic framework for smart cities development by gradually transforming urban communities into smart-energy systems. This framework is based on multidisciplinary practices regarding the staged planning of smart communities and develops smart transformation concepts to enhance capacities toward the preservation, revitalization, livability, and sustainability of a community. In this study, we focused on the concept of smart and zero-carbon communities by using technology and infrastructure. We also considered the premise of the “community” and the related social, technological, and economic aspects. The decision constructs are explained from the perspective of a bottom-up approach ranging from preliminary inspections to economic investment planning. The study proposed a set of decision constructs aimed at allowing planners, engineers, and investors to have different alternatives at their disposal and select a feasible set of practical solutions for smart transformations accordingly.

Les pays riches doivent renforcer leur soutien à l'Afrique et aux pays vulnérables pour faire face aux impacts passés, présents et futurs du changement climatique. Le rapport 2022 du Groupe d'experts intergouvernemental sur l'évolution du climat brosse un tableau sombre de l'avenir de la vie sur terre, caractérisé par l'effondrement des écosystèmes, l'extinction des espèces et les risques climatiques tels que les vagues de chaleur et les inondations1. Ceux-ci sont tous liés à des problèmes de santé physique et mentale, avec des conséquences directes et indirectes de l'augmentation de la morbidité et de la mortalité. Las naciones ricas deben intensificar el apoyo a África y a los países vulnerables para abordar los impactos pasados, presentes y futuros del cambio climático. El informe de 2022 del Grupo Intergubernamental de Expertos sobre el Cambio Climático pinta un panorama oscuro del futuro de la vida en la tierra, caracterizado por el colapso de los ecosistemas, la extinción de especies y los peligros climáticos como las olas de calor y las inundaciones.1 Todos ellos están relacionados con problemas de salud física y mental, con consecuencias directas e indirectas del aumento de la morbilidad y la mortalidad. Wealthy nations must step up support for Africa and vulnerable countries in addressing past, present, and future impacts of climate change. The 2022 report of the Intergovernmental Panel on Climate Change paints a dark picture of the future of life on earth, characterised by ecosystem collapse, species extinction, and climate hazards such as heatwaves and floods.1 These are all linked to physical and mental health problems, with direct and indirect consequences of increased morbidity and mortality. يجب على الدول الغنية زيادة دعمها لأفريقيا والبلدان الضعيفة في معالجة آثار تغير المناخ في الماضي والحاضر والمستقبل. يرسم تقرير الهيئة الحكومية الدولية المعنية بتغير المناخ لعام 2022 صورة قاتمة لمستقبل الحياة على الأرض، والتي تتميز بانهيار النظام البيئي، وانقراض الأنواع، والمخاطر المناخية مثل موجات الحر والفيضانات. 1 ترتبط جميعها بمشاكل الصحة البدنية والعقلية، مع عواقب مباشرة وغير مباشرة لزيادة المراضة والوفيات.

Application of local energy resources in the buildings encounters such systems with both uncertainties in the produced power and failures (events) of the resources. The energy planning excluding uncertainty and events may be economically efficient but it is not resilient and practical. This paper provides a platform for energy management in the building under a set of realistic failures and uncertainties. The energy resilience is improved and the energy cost is decreased at the same time while all events and uncertainties are modeled. A typical building integrated with solar-battery-grid is studied. The resilience index is to minimize the loss of demanded service following all possible events. Three objective functions are defined and compared including (i) resilience cost, (ii) energy cost, (ii) resilience and energy costs together. The stochastic mixed integer linear programming is implemented to minimize the objective functions. The results validate that the developed toolkit can cope with all events and uncertainties with minimum operating cost and maximum resilience. The optimal tradeoff between operating cost, resilience, and uncertainty is presented. The results demonstrate that the uncertainty and resilience increase the planning cost by 5.3% and 13.8%, respectively, and both of them together increase the cost by 19.5%.

Converting existing ac transmission lines to an extended multiterminal three-wire bipolar HVDC system can be considered a cost-effective way to interconnect dispersed offshore wind farms to onshore ac grids instead of building new bipolar HVDC systems. To automatically coordinate between different converters in a multiterminal HVDC (MTDC) system, droop control techniques have been adopted as an effective means without the need for fast communications between units. The droop control design is mainly dependent on the line resistances. This paper shows that the equivalent resistance of a three-wire bipolar system changes based on the operational mode. The modification to droop control design of an MTDC equipped with a three-wire bipolar system is then presented to tackle this resistance variation with the operating condition. Two types of MTDC systems are considered in this work, namely, radial parallel and meshed parallel systems. Different simulation studies have been conducted to validate the results of the presented analysis.

Cet article vise à présenter un modèle de prise de décision économique pour déterminer la conception optimale de l'éolienne (WT) pour différents nœuds de bus dans un réseau de distribution radial (RDN) basé sur le potentiel éolien du site étudié et la capacité du réseau. La fonction principale de l'objectif dans le problème d'optimisation de cette étude est la maximisation de la valeur actuelle nette (VAN) des revenus de l'énergie éolienne soumis aux variables de conception géométrique WT, y compris le diamètre du rotor et la hauteur de la tour ; et sous les contraintes du RDN pour maintenir la stabilité du système électrique. Les emplacements adéquats parmi les différents nœuds de bus pour l'installation d'éoliennes sont ceux avec la valeur maximale de la VAN. En outre, la caractéristique intermittente de l'énergie éolienne conduit à l'utilisation d'un réseau neuronal artificiel (RNA) dans la prévision de la vitesse du vent pour une bonne estimation de l'énergie éolienne générée. L'efficacité du modèle proposé a été validée à l'aide des RDN de bus IEEE 9 et IEEE 33. Les résultats démontrent que la détermination de la conception de l'éolienne n'est pas liée à la puissance du potentiel éolien mais principalement à la capacité du RDN connecté. Este documento tiene como objetivo presentar un modelo de toma de decisiones económicas para determinar el diseño óptimo de aerogeneradores (WT) para diferentes nodos de bus en una Red de Distribución Radial (RDN) basado en el potencial eólico del sitio estudiado y la capacidad de la red. La función principal del objetivo en el problema de optimización de este estudio es la maximización del Valor Actual Neto (VPN) de los ingresos de energía eólica sujetos a las variables de diseño geométrico de WT, incluido el diámetro del rotor y la Altura de la Torre; y bajo las restricciones de RDN para mantener la estabilidad del sistema de energía. Las ubicaciones adecuadas entre los diferentes nodos de bus para la instalación de WT son aquellas con el valor máximo de NPV. Además, la característica intermitente de la energía eólica conduce al uso de una Red Neuronal Artificial (ANN) en el pronóstico de la velocidad del viento para una buena estimación de la energía eólica generada. La efectividad del modelo propuesto se validó utilizando IEEE 9 e IEEE 33 Bus RDN. Los resultados demuestran que la determinación del diseño de WT no está relacionada con la potencia del potencial eólico, sino principalmente con la capacidad de la RDN conectada. This paper aims to present an economic decision-making model for determining the optimal wind turbine (WT) design for different bus nodes in a Radial Distribution Network (RDN) based on the wind potential of the studied site and grid capability.The main objective function in the optimization problem of this study is the maximization of the Net Present Value (NPV) of wind energy incomes subject to the WT geometrical design variables, including the rotor diameter and Tower Height; and under the RDN constraints to maintain the power system stability.Adequate placements among the different bus nodes for WT installation are those with the maximum NPV value.Furthermore, the intermittent characteristic of wind energy leads to the use of an Artificial Neural Network (ANN) in wind speed forecasting for good estimation of the generated wind energy.The effectiveness of the proposed model was validated using IEEE 9 and IEEE 33 Bus RDNs.The results demonstrate that the WT design determination is not related to the power of the wind potential but mostly to the capability of the connected RDN. تهدف هذه الورقة إلى تقديم نموذج لصنع القرار الاقتصادي لتحديد التصميم الأمثل لتوربينات الرياح (WT) لعقد الناقل المختلفة في شبكة التوزيع الشعاعية (RDN) بناءً على إمكانات الرياح للموقع المدروس وقدرة الشبكة. وتتمثل الوظيفة الرئيسية للهدف في مشكلة التحسين لهذه الدراسة في تعظيم القيمة الحالية الصافية (NPV) لدخول طاقة الرياح الخاضعة لمتغيرات التصميم الهندسي WT، بما في ذلك قطر الدوار وارتفاع البرج ؛ وتحت قيود RDN للحفاظ على استقرار نظام الطاقة. المواضع المناسبة بين عقد الناقل المختلفة لتركيب WT هي تلك التي لها أقصى قيمة NPV. علاوة على ذلك، تؤدي الخاصية المتقطعة لطاقة الرياح إلى استخدام شبكة عصبية اصطناعية (ANN) في التنبؤ بسرعة الرياح لتقدير جيد لطاقة الرياح المتولدة. تم التحقق من فعالية النموذج المقترح باستخدام IEEE 9 و IEEE 33 Bus RDNs. تظهر النتائج أن تحديد تصميم WT لا يرتبط بقوة جهد الرياح ولكن في الغالب بقدرة RDN المتصلة.