• Energy Research
• engineering and technology close
• 13. Climate action close
• 11. Sustainability close
• 3. Good health close
• 4. Education close
• PT close

The growing search for alternative energy sources is not only due to the present shortage of non-renewable energy sources, but also due to their negative environmental impacts. Therefore, a lot of attention is drawn to the use of biomass as a renewable energy source. However, using biomass in its natural state has not proven to be an efficient technique, giving rise to a wide range of processing treatments that enhance the properties of biomass as an energy source. Torrefaction is a thermal process that enhances the properties of biomass through its thermal decomposition at temperatures between 200 and 300 °C. The torrefaction process is defined by several parameters, which also have impacts on the final quality of the torrefied biomass. The final quality is measured by considering parameters, such as humidity, heating value (HV), and grindability. Studies have focused on maximizing the torrefied biomass’ quality using the best possible combination for the different parameters. The main objective of this article is to present new information regarding the conventional torrefaction process, as well as study the innovative techniques that have been in development for the improvement of the torrefied biomass qualities. With this study, conclusions were made regarding the importance of torrefaction in the energy field, after considering the economic status of this renewable resource. The importance of the torrefaction parameters on the final properties of torrefied biomass was also highly considered, as well as the importance of the reactor scales for the definition of ideal protocols.

East Lisbon is being exposed to large-scale urban regeneration processes, where luxury residential projects and mixed-use spatial developments are already underway. Thus, it is a living laboratory for “smart”, “creative” and “green” projects, as well as related urban public space interventions. Braço de Prata is an urban space overlooked by developers, being surrounded by obsolete industrial buildings. Concerning the recent interest in international investments in brownfield regeneration and greenfield developments, it represents an attractive urban terrain as a post-industrial working-class neighbourhood, where “smart” and “green” suggest transforming space so that both new and old residents can live and work together and share public space regardless of analysis on their environmental recognitions. The aim of this paper is to present an empirical evaluation model that examines the possible impacts of environmental negligence through the reorganisation of the physical and social fabric. The analyses focus on dwellers’ moral understanding of their changing environment as site-specific domains to address the unique conditions that affect transiently defined presumptions about the collective needs. Taking an evaluative approach in the Braço de Prata case, this paper demonstrates the specific socio-ecological implications of urban inequality in post-industrial neighbourhoods that could be threatened by new decisions, both through urban planning approaches and instruments.

Abstract Lighting simulation is a useful instrument in predicting lighting conditions in buildings. Modelers can use several matrix methods according to the buildings’ characteristics and the objectives of the analysis. However, it is unknown which methods are the most appropriate for lighting analysis of heritage buildings. The Joanina Library located in the University of Coimbra – a World Heritage building – was used to compare different matrix methods (2PH, 3PH, and 5PH) under several solar models (BRL, DISC, Perez, and Reindl) using Radiance-based simulations. On-site measurements (indoor and outdoor) were used to calculate each method’s accuracy under different solar models. The combination of the 2PH method with the DISC solar model presented the highest accuracy with an average MBEr and RMSEr of 2.8 % and 43.6 %, respectively. Therefore, the 2PH method was the best choice for the case study, even though the 3PH method may also be considered, especially for parametric studies of improving measures.

This research studied the impacts of the environmental Kuznets curve and the determinants of economic growth for Visegrad countries from 1990 to 2018. This paper reflects on the effects of renewable and non-renewable energy, urban population, foreign direct investment, economic growth, and carbon dioxide emissions. According to our results, the panel of unit root tests showed that the variables under study are integrated into the first differences. Considering the empirical results for the environmental Kuznets curve, we observe that economic growth is positively correlated with pollution emissions; nevertheless, the squared income per capita is negatively impacted by carbon dioxide emissions. Energy consumption increases carbon emissions, and foreign direct investment confirms the pollution halo hypothesis. Therefore, the econometric results showed that renewable energy consumption promotes regional growth. Consequently, urban population and foreign direct investment positively correlate with economic growth.

Cloud computing and sustainability have become part of a core strategy in organizations globally and locally, since their characteristics assist both businesses and individuals to become unique and exclusive in their work and study. Businesses and individuals should integrate sustainability in their strategy and to include cloud computing technology as a tool for sustainable work, especially in the Information Technology (IT) departments to cut costs and increase efficiencies and productivity. This paper examines European organizations' awareness of cloud computing and sustainability opportunities and risks, via an online survey targeting 56 Information Technology managers in Europe. A Cloud Computing Conceptual model was developed using structural equation modeling (SEM) to evaluate the survey results. The study results confirmed that cloud computing technology opportunities, including sustainability in the organization's strategy, will enhance their job performance and job satisfaction, use and awareness; however, security, privacy and risks are still a major concern.

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.

This paper presents a methodology that quantifies the life cycle costs of concrete decks of roadway bridges that supports the decision-making regarding the optimal selection between several construction / repair alternatives. A deterioration model based on the main material and environmental characteristics of bridges is presented. Some of the most up-to-date materials that are used on concrete bridges are also presented and characterized. The quantification of the user costs is presented. These calculations are made considering the vehicle operating costs, the cost of time and accident costs. The user costs are determined by comparing the traffic costs under free flow conditions with those that arise from disrupting the free traffic flow. The created model is applied to an existing bridge, where the determination and comparison of the costs of the application of different repair alternatives are analysed. At the end, the main conclusions and recommendations are presented.

Abstract This paper addresses the importance of the probabilistic analysis in determining the wave energy potential to support the design of electrical generators for wave energy conversion. The irregular activity of ocean waves induces variable frequencies and amplitudes of operation for point absorbers electrical generators, which may lead to the construction of inefficient electrical machines. Applying probabilistic models to describe the ocean wave's behavior allows the determination of the values most likely to be sampled for ocean-state parameters. Knowing these values, the most expected ocean wave potential can be determined and a proper device design can be performed. This work also refers to the importance of using the joint probability models instead of the marginal ones. Seven locations at the Portuguese coast are evaluated in order to determine their wave energy resource potential.

Abstract Despite the significant growth in the number of published life-cycle assessments of biofuels, important aspects have not captured sufficient attention, namely soil carbon emissions from land use change (LUC) and uncertainty analysis. The main goal of this article is to evaluate the implications of different LUC scenarios and uncertainty in the life-cycle energy renewability efficiency and GHG (greenhouse gases) intensity of wheat-based bioethanol replacing gasoline. A comprehensive assessment of different LUC scenarios (grassland or cropland converted to wheat cultivation) and agricultural practices is conducted, which results in different carbon stock change values. The types of uncertainty addressed include parameter uncertainty (propagated into LC (life-cycle) results using Monte-Carlo simulation) and uncertainty concerning how bioethanol co-product credits are accounted for. Results show that GHG emissions have considerably higher uncertainty than energy efficiency values, mainly due to soil carbon emissions from direct LUC and N2O release from cultivated soil. Moreover, LUC dominates the GHG intensity of bioethanol. Very different GHG emissions are calculated depending on the LUC scenario considered. Conversion of full- or low-tillage croplands to wheat cultivation results in bioethanol GHG emissions lower than gasoline emissions, whereas conversion of grassland does not contribute to bioethanol GHG savings over gasoline in the short- to mid-term.

Abstract This paper presents a new methodology for impact assessment—SIAM (Spatial Impact Assessment Methodology)—which is based on the assumption that the importance of environmental impacts is dependent, among other things, on the spatial distribution of the effects and of the affected environment. The information generated by the use of Geographical Information Systems (GIS) in impact identification and prediction stages of Environmental Impact Assessment (EIA) is used in the assessment of impact significance by the computation of a set of impact indices. For each environmental component (e.g., air pollution, water resources, biological resources), impact indices are calculated based on the spatial distribution of impacts. A case study of impact evaluation of a proposed highway in Central Portugal illustrates the application of the methodology and shows its capabilities to be adapted to the particular characteristics of a given EIA problem.