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Upwelling processes bring nutrient-rich waters from the deep ocean to the surface. Areas of upwelling are often associated with high productivity, offering great economic value in terms of fisheries. The sensitivity of spring/summer-time coastal upwelling systems to climate change has recently received a lot of attention. Several studies have suggested that their intensity may increase in the future while other authors have shown decreasing intensity in their equatorward portions. Yet, recent observations do not show robust evidence of this intensification. The Senegalo-Mauritanian upwelling system (SMUS) located at the southern edge of the north Atlantic system (12°N–20°N) and most active in winter/spring has been largely excluded from these studies. Here, the seasonal cycle of the SMUS and its response to climate change is investigated in the database of the Coupled Models Inter comparison Project Phase 5 (CMIP5). Upwelling magnitude and surface signature are characterized by several sea surface temperature and wind stress indices. We highlight the ability of the climate models to reproduce the system, as well as their biases. The simulations suggest that the intensity of the SMUS winter/spring upwelling will moderately decrease in the future, primarily because of a reduction of the wind forcing linked to a northward shift of Azores anticyclone and a more regional modulation of the low pressures found over Northwest Africa. The implications of such an upwelling reduction on the ecosystems and local communities exploiting them remains very uncertain.

Abstract This paper investigates the optimal choice of building energy efficiency (BEE) standard in the context of centralised urban district heating system in northern China. By employing a techno-economic analysis approach, we demonstrate that the current BEE standard implemented in the Chinese cities should be tightened further in order to achieve a socially optimal level. Without considering the externality costs associated with carbon dioxide (CO2) emissions, current BEE standards need to be upgraded to the equivalent level of French RT2005 standard coupled with a properly designed district coal-fired Combined Heat and Power (CHP). In contrast, the equivalent efficiency standard of Swedish building code is preferably to be implemented in the case of explicit carbon emission restriction as long as the marginal cost of carbon emission (carbon price) is sufficiently high. The fuel-switching policy (from coal to natural gas) in the urban district heating system would result in significant increase in overall costs if the BEE upgrade is not taken into account simultaneously. It is also found that BEE improvements in northern Chinese cities are more cost-effective than investing in low-carbon technologies such as wind power or Carbon Capture and storage in the EU and US with regard to CO2 emissions mitigation.

The transportation impact on pollution and global climate change, has forced the automotive sector to search for more ecological solutions. Owing to the different properties of Fuel Cell (FC), real potential for reducing vehicles’ emissions has been witnessed. The optimization of FC integration within Electric Vehicles (EVs) is one of the original solutions. This paper presents an innovating solution of multi-stack Fuel Cell Electrical Vehicle (FCEV) in terms of efficiency, durability and ecological impact on environment. The main objective is to illustrate the interest of using the multi-stack FC system on the global autonomy, cycling, and efficiency enhancement, besides optimizing its operation performance.

The climate agenda in France and several other countries is a complex combination of unilateral commitments with regional and international objectives. When analyzing national policies, the findings of worldwide analyses are of limited accuracy and the large aggregates on which they are built level out most local specificities and inertia. Specific. assessments are hence needed. This paper quantifies the dynamic evolution of carbon values for French climate and energy policy. Its time dependency over successive periods and the effects of setting intermediate targets are evaluated using a long-term optimization model. Addressing critical issues for France, we produce consistent energy, emissions and carbon value estimates with a 5-year time step. Our results are situated above the upper range of carbon value estimates of world models with an overlapping zone. We show that the official policy guideline value is only consistent with an optimistic combination of assumptions. The central estimates are 4 times greater than the guideline carbon value for 2050 and up to 14 times greater in 2020 because of short-term inertia that are costly to move. We also find that with intermediate objectives, the carbon value's dynamic is more than a simple upward curve and that its variability is itself time dependent

AbstractThe European Union aspires to reducing the import dependency of raw materials that are critical to its industries. In this respect, mineral resource information and data sharing by European Geological Surveys is crucial. In 2010, the European Commission identified 14 critical non-energy non-agricultural raw materials. This list was updated in 2014. This article presents the Critical Raw Material (CRM) Map of Europe produced by EuroGeoSurvey's Mineral Resources Expert Group. This map shows European mineral deposits from the EU FP7 ProMine project database, as containing critical commodities, according to the list of CRM published by the European Commission.

La quête de décarbonisation et de décentralisation du réseau électrique actuel a permis une forte pénétration des ressources énergétiques distribuées en bordure du réseau de distribution. La diversité, la complexité et le nombre croissant de ces ressources énergétiques posent actuellement un défi à leur gestion. Cela a entraîné l'émergence de divers écosystèmes énergétiques qui utilisent diverses stratégies et initiatives organisationnelles communautaires comme formes de techniques de gestion. Il existe également des modèles commerciaux et des structures de gouvernance correspondants qui sont innovants et technologiquement perturbateurs pour les opérations du réseau actuel. Une analyse de cinq cas représentatifs de ces communautés d'énergie renouvelable est réalisée en utilisant des projets réels comme études de cas. Les domaines d'intervention pris en compte dans cette étude comprenaient les structures organisationnelles et de gouvernance, les rôles et la relation entre les principales parties prenantes/propriétaires, la façon dont ces écosystèmes interagissent avec le réseau électrique et le rôle des collaborations. Les résultats de l'étude ont révélé que chaque catégorie d'écosystème a des structures organisationnelles et de gouvernance similaires, bien qu'elles puissent être constituées différemment. En termes de propriété, il a été constaté que les coopératives énergétiques, les municipalités et les communautés possédaient une plus grande part de ces ressources énergétiques. En outre, il a été constaté que la plupart de ces écosystèmes interagissaient avec le réseau en fournissant de l'énergie excédentaire de la communauté au réseau électrique, tandis que d'autres fonctionnent de manière isolée du réseau. À l'exception d'un cas, tous les autres ont montré des éléments de collaboration comme faisant partie intégrante de leur mode de fonctionnement. La búsqueda de descarbonizar y descentralizar la red eléctrica actual ha permitido una alta penetración de los Recursos de Energía Distribuida en el borde de la red de distribución. La diversidad, complejidad y número creciente de estos recursos energéticos suponen actualmente un reto para su gestión. Esto ha dado lugar a la aparición de diversos ecosistemas energéticos que utilizan diversas estrategias e iniciativas organizativas basadas en la comunidad como formas de técnicas de gestión. También hay modelos de negocio y estructuras de gobierno correspondientes que son innovadores y tecnológicamente disruptivos para las operaciones de la red actual. Se realiza un análisis de cinco casos representativos de estas Comunidades de Energías Renovables utilizando proyectos de la vida real como casos de estudio. Las áreas de enfoque consideradas en este estudio incluyeron estructuras organizativas y de gobernanza, roles y la relación entre las partes interesadas/propietarios clave, cómo estos ecosistemas interactúan con la red eléctrica y el papel de las colaboraciones. El resultado del estudio reveló que cada categoría de ecosistema tiene estructuras organizativas y de gobernanza similares, aunque pueden estar constituidas de manera diferente. En términos de propiedad, se encontró que las cooperativas de energía, los municipios y las comunidades poseen una mayor parte de estos recursos energéticos. Además, se descubrió que la mayoría de estos ecosistemas interactúan con la red al suministrar el exceso de energía de la comunidad a la red eléctrica, mientras que otros operan aislados de la red. Aparte de un caso, todos los demás mostraron elementos de colaboración como un componente integral de su modo de operación. The quest to decarbonize and decentralize the current power grid has enabled high penetration of Distributed Energy Resources at the edge of the distribution network. The diversity, complexity and growing numbers of these energy resources currently pose a challenge to managing them. This has resulted in the emergence of various energy ecosystems which use diverse community-based organizational strategies and initiatives as forms of management techniques. There are also corresponding business models and governance structures that are innovative and technologically disruptive to the operations of the current grid. An analysis of five representative cases of these Renewable Energy Communities is performed using real-life projects as case studies. The focus areas considered in this study included organizational and governance structures, roles, and the relationship between key stakeholders/owners, how these ecosystems interact with the power grid, and the role of collaborations. The outcome of the study revealed that each category of ecosystem has similar organizational and governance structures although they may differently be constituted. In terms of ownership, energy cooperative, municipalities, and communities were found to own a greater share of these energy resources. Furthermore, most of these ecosystems were found to interact with the grid by supplying excess energy from the community to the power grid whilst others operate in isolation from the grid. Apart from one case, all the others showed elements of collaborations as an integral component of their mode of operations. وقد مكن السعي إلى إزالة الكربون واللامركزية من شبكة الطاقة الحالية من الاختراق العالي لموارد الطاقة الموزعة على حافة شبكة التوزيع. يشكل تنوع موارد الطاقة هذه وتعقيدها وأعدادها المتزايدة حاليًا تحديًا لإدارتها. وقد أدى ذلك إلى ظهور مختلف النظم الإيكولوجية للطاقة التي تستخدم استراتيجيات ومبادرات تنظيمية مجتمعية متنوعة كأشكال لتقنيات الإدارة. هناك أيضًا نماذج أعمال وهياكل حوكمة مقابلة مبتكرة ومدمرة تقنيًا لعمليات الشبكة الحالية. يتم إجراء تحليل لخمس حالات تمثيلية لمجتمعات الطاقة المتجددة هذه باستخدام مشاريع واقعية كدراسات حالة. وشملت مجالات التركيز التي تم النظر فيها في هذه الدراسة الهياكل التنظيمية والحوكمة، والأدوار، والعلاقة بين أصحاب المصلحة/المالكين الرئيسيين، وكيفية تفاعل هذه النظم الإيكولوجية مع شبكة الطاقة، ودور التعاون. كشفت نتائج الدراسة أن كل فئة من فئات النظام الإيكولوجي لها هياكل تنظيمية وحوكمة متشابهة على الرغم من أنه قد يتم تشكيلها بشكل مختلف. من حيث الملكية، وجد أن تعاونيات الطاقة والبلديات والمجتمعات تمتلك حصة أكبر من موارد الطاقة هذه. علاوة على ذلك، وجد أن معظم هذه النظم الإيكولوجية تتفاعل مع الشبكة من خلال توفير الطاقة الزائدة من المجتمع إلى شبكة الطاقة بينما تعمل النظم الأخرى بمعزل عن الشبكة. وبصرف النظر عن حالة واحدة، أظهرت جميع الحالات الأخرى عناصر التعاون كجزء لا يتجزأ من طريقة عملياتها.

Marine renewable energies (MRE) allow the diversification of the energy mix and are thus developing rapidly. The extraction of tidal energy is one of the most promising MRE and is nowadays in a preindustrial phase. The Alderney Race (Raz Blanchard in French), situated between the island of Alderney (Channel Islands) and the Cap de la Hague in France, capitalizes a resource estimated between 5 and 14 TWh/year. This great tidal resource attracts tidal energy developers. Harnessing the high potential of the Alderney Race requires deploying numerous turbines in arrays. The purpose of this paper is to investigate the influence of the wake effects on the electrical dynamics of commercial tidal farms. The proposed methodology is applied to a hypothetical tidal farm in the Alderney Race. The influence of the wake effects on the power produced by a tidal farm is assessed by comparing simulations where the effect is neglected to simulations with wake effects. Two operational conditions are analyzed: Normal operation (one-day simulation with varying tidal speed); grid disturbances (voltage dip at the tidal farm point of common coupling). Simulations show that neglecting the wake effect implies significant errors in active power estimation at the point of common coupling during normal operation. Moreover, differences in the behavior of the system during voltage dip occur if the wake effect is not taken into account.

Decarbonisation of energy systems requires deep structural change. The purpose of this research was to analyse the rates of change taking place in the energy systems of each Member State of the European Union (EU), and the EU in aggregate, in the light of the EU's climate change mitigation objectives. Trends on indicators such as sectoral activity levels and composition, energy intensity, and carbon intensity of energy were compared with decadal benchmarks derived from deep decarbonisation scenarios. The methodology applied provides a useful and informative approach to tracking decarbonisation of energy systems. The results show that while the EU has made significant progress in decarbonising its energy system. On a number of indicators assessed the results show that a significant acceleration from historical levels is required in order to reach the rates of change seen on the future benchmarks for deep decarbonisation. The methodology applied provides an example of how the research community and international organisations could complement the transparency mechanism developed by the Paris Agreement on climate change, to improve understanding of progress toward low-carbon energy systems.