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Transport is one of the sectors of the energy consumption where the presence of renewable energies is lower and its increase is hard to achieve especially in countries that import all the fuels that they consume. This paper addresses the progress that Portugal is making toward a more sustainable transport sector. A near- and medium- term scenario analysis is performed, based on the energy consumption in the past and on a detailed evaluation of the trends for renewable energy in the transport sector. The near-term scenarios aim at portraying the conditions that allow the country to fulfill the target of 10% renewable share in transportation established by the European Union. The medium-term scenarios highlight the implications, in terms of emission reduction and of energy independence, deriving from the use of electric vehicles and natural gas, synthetic and fossil, as alternatives to liquid fuels. The results show that electric vehicles would substantially reduce the total energy consumption and the greenhouse gas emissions, while the promotion of routes for synthetic natural gas would contribute to taking advantage of local resources. The paper also provides some insights about the design of future policies to build a more sustainable transport sector. [ABSTRACT FROM AUTHOR]

The coherency of research, development, and innovation processes are vital in promoting a more resource efficient society. Sustainability-oriented innovation systems define specific kinds of innovation systems, i.e. those that are directed to the aims of sustainable development. This paper develops an integrated method with four layers of analysis to evaluate the priorities and performances of such systems. The method is applied to a sample of emerging and innovation based economies, namely Brazil, Russia, India, China, South Africa, Turkey, and Singapore. The analyses consider the 6 main activities or functional dynamics of innovation systems and a set of 19 keywords. The keywords relate to the thematic clusters of renewable energy technologies, energy efficiency, and environmental management. The priorities of the countries in each main interaction of the system are classified accordingly. The priorities are compared to the existing level of specialization in the keywords based on the intermediate outputs of the system. The analyses cover 153,838 papers and 15,138 patents between the years 2003 and 2014. A Sustainable Innovation Index is developed to aggregate the normalized values of country performance across all keywords. Singapore receives the highest value (21.17) and the average of Brazil, Russia, India, China, and South Africa is 14.91. The results determine the ability of countries to align priorities and performance towards more mature innovation systems for sustainable development. [ABSTRACT FROM AUTHOR]

Exploring the sustainability of urban ecosystem is becoming a key area in global sustainable development. Urban metabolism is an effective analysis tool for the study of urban ecosystem. In this regard, how to evaluate the level of urban sustainable development and identify the key factors that affect urban metabolism is critical. Many studies on urban metabolism have been explored during the past half century, but few concerns about the key factors that affect urban metabolism. Therefore, this paper fills such a gap by combining emergy and Logarithmic Mean Divisia Index (LMDI) methods in order to analyze the sustainable development level and identify the driving forces of emergy utilization, respectively. A typical industrial city, Shenyang in northeast China, was chosen as a case study city in this paper. Results show that renewable resource utilization in Shenyang was very limited from 2000 to 2010, while nonrenewable resources and the imported resources increased rapidly. During this period, total emergy utilization of Shenyang increased from 8.52 × 10 22 sej to 21.53 × 10 22 sej, and emergy density increased with annual increasing rate of 10.34%, demonstrating a fast development of the economy and high level of resident's consumption. LMDI method was employed to analyze the driving forces of emergy consumption from the aspects of scale, structure and intensity. Results show that the rapid increase of emergy utilization in Shenyang was mainly caused by the expansion of economic scale, while emergy intensity greatly contributed to offset total consumption, and industry structure played a marginal role, with a minor value for its growth. Based upon these results, several policy recommendations were raised, including the use of more renewable and clean energy sources, a regenerative and preventative eco-industrial development approach, and capacity-building efforts, so that the overall environment pressure on urban development can be reduced. [ABSTRACT FROM AUTHOR]

In light of various environmental problems and challenges concerning resource allocation, the utilisation of renewable resources is increasingly important for the efficient use of raw materials. Therefore, cascading utilisation (i.e., the multiple material utilisations of renewable resources prior to their conversion into energy) and approaches that aim to further increase resource efficiency (e.g., the utilisation of by-products) can be considered guiding principles. This paper therefore introduces the Special Volume "Improved Resource Efficiency and Cascading Utilisation of Renewable Materials". Because both research aspects, resource efficiency and cascading utilisation, belong to several disciplines, the Special Volume adopts an interdisciplinary perspective and presents 16 articles, which can be divided into four subjects: Innovative Materials based on Renewable Resources and their Impact on Sustainability and Resource Efficiency, Quantitative Models for the Integrated Optimisation of Production and Distribution in Networks for Renewable Resources, Information Technology-based Collaboration in Value Generating Networks for Renewable Resources, and Consumer Behaviour towards Eco-friendly Products. The interdisciplinary perspective allows a comprehensive overview of current research on resource efficiency, which is supplemented with 15 book reviews showing the extent to which textbooks of selected disciplines already refer to resource efficiency. This introductory article highlights the relevance of the four subjects, presents summaries of all papers, and discusses future research directions. The overall contribution of the Special Volume is that it bridges the resource efficiency research of selected disciplines and that it presents several approaches for more environmentally sound production and consumption. [ABSTRACT FROM AUTHOR]

The world is experiencing an unprecedented transition towards a low-carbon and renewable-based energy system, driven by the imperatives of mitigating climate changes, building climate resilience and ensuring sustainable development. Recently, polygeneration systems based on renewable energies have emerged as a viable solution to support the energy transition since they can improve resource utilization and energy efficiency, thus reducing the dependency on fossil fuels and the environmental impacts on ecosystems. Renewable polygeneration systems can play a significant role in the decarbonization of the food processing industry due to its high thermal energy demand at low and medium temperature levels. This paper presents a detailed analysis of a renewable polygeneration system integrating solar, geothermal and biomass energies and able to produce electricity, heat and cold water. The novelty of this study is the analysis of polygeneration system configurations relying solely on renewable energies and the optimization of the strategy to control the energy exchange between power systems, storage facilities and utilities. Two system configurations based on different power technologies and control strategies are investigated and compared, considering as end-user a milk production process with hot and cold water requirements at different temperature levels and load profiles. To this end, a dynamic model in Matlab/Simulink has been developed to simulate the behaviour of the polygeneration system over time and evaluate its overall energy performance parameters. For each system configuration, the optimal operating strategy has been identified by maximizing the energy conversion efficiency and minimizing the unmet thermal and cooling loads. Simulation results highlighted that, compared to polygeneration systems relying only on fluctuating renewable energies, those including a backup heat source (i.e., a biomass boiler) were able to meet the thermal energy needs of larger and more complex milk production processes. [ABSTRACT FROM AUTHOR]

For the past three decades, the notion of sustainable cities has become central in planning and managing urban areas in the world and the large-scale city formation has been formed in big cities. As a result of economic growth and urban transformation, Shanghai, a major Chinese international metropolis, faces ongoing issues with resource waste and low energy utilization. Therefore, this paper aims to consider the availability of water for energy production from a consumption-based perspective and estimate the water footprint of the energy supply using a regional input-output analysis approach for Shanghai. As a result, we conclude that the water footprint of the energy supply of Shanghai is about 1.28 billion m 3 in 2007, with 46.1% of water used for electricity and heat supply. The total water withdrawal by the energy sector is about 2.35 billion m 3 and additional water withdrawal needed is about 35% of the total water withdrawals by the energy sector in Shanghai. Furthermore, an energy self-sufficiency scenario was developed, and the scenario analysis reveals that 55% more water would be required to ensure a self-sufficient energy sector. To guarantee future regional energy security, it is important to manage water resources effectively by allocating water resources among sectors. [ABSTRACT FROM AUTHOR]

Renewable energy resources are currently being deployed on a large scale to meet the requirements of increased energy demand, mitigate the environmental pollutants, and achieve socio-economic benefits for sustainable development. The integration of such distributed energy sources into utility grid paves the way for microgrids. The microgrid concept is introduced to have a self-sustained system consisting of distributed energy resources that can operate in an islanded mode during grid failures. In microgrid, an energy management system is essential for optimal use of these distributed energy resources in intelligent, secure, reliable, and coordinated ways. Therefore, this review paper presents a comparative and critical analysis on decision making strategies and their solution methods for microgrid energy management systems. To manage the volatility and intermittency of renewable energy resources and load demand, various uncertainty quantification methods are summarized. A comparative analysis on communication technologies is also discussed for cost-effective implementation of microgrid energy management systems. Finally, insights into future directions and real world applications are provided. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of the impact of renewable/non-renewable energy consumption on ecological quality and economic growth can serve to the sustainability of energy, ecology, and economy. This paper provides a new perspective of the comprehensive system of the 3E model, and introduces indicator of social factor to examine the non-linear effects of urbanization on energy, economy, and the environment. A threshold panel regression model is developed using the data of 120 countries in the last 20 years. In the proposed model, renewable energy and non-renewable energy are explanatory variables, economic growth and ecological footprint are explained variables, and urbanization are threshold variable. Non-linear relationships are concretized and quantified in the research of global and different income groups. The results show that global renewable energy can promote economic growth while improving the environment. As the urbanization rate increases, the negative effect of renewable energy on the ecological footprint first weakens and then increases, and the positive coefficient on the economy maintains a growth trend. Non-renewable energy has a more obvious positive effect on economic growth, but it increases the ecological footprint. The development of urbanization strengthens its promotion of the economy and reduces its pressure on the environment. From the perspective of different income groups, renewable energy does not always suppress the ecological footprint. The energy transition reduces economic growth in the initial stages of urbanization in certain regions. After crossing the threshold, the coefficient changes of different income groups have similarities and differences. Based on the conclusions, some recommendations are put forward, including promoting the transformation of energy consumption structure, improving energy efficiency and accelerating the process of urbanization. The model in this paper is suitable for investigating the nonlinear impact of urbanization on the 3E system through panel data, and can provide theoretical support for studying the threshold effect of a country or economy. This study also shows the importance of renewable energy and the indirect effects of urbanization, which is helpful for formulating global sustainable and coordinated development policies. [Display omitted] • A new perspective of the energy-economy-environment (3E) model is proposed. • Threshold models enable the non-linear relationships to be concretized and quantified. • Global renewable energy improves the environment while promoting economic growth. • Urbanization reduces the pressure on the environment from energy consumption. • Urbanization strengthens the positive effect of energy on economic growth. [ABSTRACT FROM AUTHOR]

Military expenditures in the Asia-Pacific region have grown rapidly in tandem with economic growth over the past few decades. The military sector's impact on environmental change has not been given enough attention. Renewable energy utilization in the Asia-Pacific region also has increased significantly. This paper examines the relationship between militarization, economic growth, renewable energy utilization, and environmental change in the 15 countries participating in the Regional Comprehensive Economic Cooperation (RCEP) agreement using data that covers 1990–2018. The panel cointegration and cross section autoregressive distributed lag (CS-ARDL) models are used to examine the long- and short-term relationships among variables. The empirical results show that economic growth and rising levels of militarization have a positive impact on a country's ecological footprint. The increase in military capital intensity has aggravated the environmental harm caused by the military. Improving the utilization rate of renewable energy can alleviate detrimental environmental effects in the long term. This study also puts forward policy recommendations from the policy perspective of sustainable development to reduce the level of regional militarization and improve the utilization of renewable energy. • Militarization is the cause of environmental degradation. • The increase of military capital intensity will aggravate its damage to the environment. • Renewable energy use can ease ecological footprint expansion. [ABSTRACT FROM AUTHOR]

Increased competition and reduced profit margins are pushing manufacturing plants to find ways to improve operational efficiency and reduce costs. At the same time, government incentives and community initiatives are encouraging the industrial sector to pursue sustainability in operation and energy consumption. This has introduced a paradigm shift where the focus of plant operation is moving from solely cost reduction to one that considers asset management, emission control, and utilization of alternative energy resources. Mathematically speaking, the problem is changing from a single objective optimization to one with multiple objective functions that may at times be contradictory. The focus of this paper is to propose a methodology for management of an industrial plant considering the above factors. It is assumed that the plant is equipped with distributed generation (DG), and can also participate in demand response (DR). Further, the effect of ambient temperature on the lifetime and available capacity of assets such as the plant transformer has been taken into account and incorporated into their daily schedule. The objective is then to find an optimal solution for operating various workstations in such a way that it minimizes the operational costs, the emissions produced, and the loss of life of assets exposed to excess temperatures. A multi-objective optimization problem is therefore formulated through extended lexicographic goal programming, which is further modified to ensure Pareto optimality. A case study has also been presented for a manufacturing plant for luxury vehicle cockpit assembly line. [ABSTRACT FROM AUTHOR]

Educational sector is growing drastically as a result of upward trend of population. These schools require tremendous quantities of energy units to be generated and consumed. As a result, this will impact negatively on the environment by increasing the carbon emissions and depletion of non-renewable energy resources. Moreover, the harsh climate condition contributes substantially to increase the energy consumption in various weather zones in the world. Therefore, several energy efficiency plans have been developed to improve the energy performance of the schools facilities globally. Hence, this paper discusses the energy management program as a sustainable strategy that applicable on the schools. This program is designed for the schools to improve the energy efficiency, indoor environmental quality and adopting the best management practices during the operating stages. This research has developed a customized energy management program for one of the schools in UAE. It has concluded the findings by using computerized hourly thermal modeling. The energy model has evaluated the proposed energy conservation measures and the best practices that were generated by the energy management program steps. This case shows that the energy performance could be improved substantially by 35%. Thus, the energy use index of the audited school that adopted the energy management program has reduced from 438 kWh/m 2 /year to 285 kWh/m 2 /year. The proposed energy management program has been articulated in this study as a consecutive and linear progression. This methodology presents several steps to mitigate the carbon emission by addressing the sustainability dimensions; economic, environment and social aspects. This study discusses the steps and the work flow of developing the energy management program and the anticipated outcomes for the school's buildings. The program considers practical ECMs along with the students and teachers participation and interaction. Furthermore, it highlights the success criteria that assure the sustainability of the energy efficiency at the operating life cycle of school's facilities. [ABSTRACT FROM AUTHOR]

Energy sectors of all the countries around the world are faced with a big challenge: the energy transition under the imperative of continuous reduction of carbon dioxide emissions. The energy transition and the sustainability constraints pose a significant challenge for engineers, researcher and scientists developing new and clean energy-efficient technologies. Energy production and transformations, along with its storage, distribution and consumption, are achieved by utilising new and clean energy technologies, with the goal of the continuous increase of energy efficiency, the growth of renewable energy sources utilisation, the uninterrupted switch from fossil fuels to alternative energy sources, and the continued reduction of CO2 emissions. This editorial paper addresses the latest progress and the findings in research and developments in the sustainable energy technologies, energy and environment systems from selected papers of the conference on Sustainable Development of Energy, Water and Environment Systems held in 2019. [ABSTRACT FROM AUTHOR]

Is there a trade-off between spending on the green economy and an economy's strength? This paper addresses this question by estimating output multipliers for spending in clean energy and biodiversity conservation, and by comparing these to multipliers of spending on non-ecofriendly energy and land use activities. Using a new international dataset, we arrive at two key results. First, we find that every dollar spent on key carbon-neutral or carbon-sink activities can generate more than a dollar's worth of economic activity, whereas non-green spending returns less than a dollar. Second, for categories of spending where formal comparisons are possible, like renewable versus fossil fuel energy, we find that multipliers on green spending are about twice as large as their non-green counterparts. The point estimates of the multipliers are 1.1–1.7 for renewable energy investment and 0.4–0.7 for fossil fuel energy investment, depending on horizon and specification. These findings survive several robustness checks and lend support to bottom-up analyses that find that stabilizing climate and reversing biodiversity loss go hand in hand with economic prosperity. [ABSTRACT FROM AUTHOR]

Among the main components of a smart city, the energy system plays a vital and core role in the transition towards a sustainable urban life. Furthermore, the utilization of renewable energy sources has been demonstrated as a significant contribution to reducing pollutant emissions and enhancing the quality of the living environment. Therefore, designing the energy systems based on clean and renewable criteria is considered a sustainable solution for smart cities. Indeed, the deep and rapid penetration of renewable energy-based technologies have been believed to very well fit into a smart city under various scales, this could supply a secure basis for a modern society with a low-carbon economy. In this review paper, the main components and roles of renewable energy resources (such as solar, wind, geothermal, hydropower, ocean, and biofuels) for the smart city were fully introduced. Besides, integrating the renewable sources form into the energy systems of smart cities was thoroughly analyzed on the basis of technical and economic criteria. Finally, existing challenges and future scenarios were also discussed in detail to clarify the progress and perspective of smart renewable energy systems for the smart city. In general, the integration of renewables into energy systems of the smart city is a sagacious perspective and solution aiming to achieve cleaner process and more sustainable development. However, the optimization issues of the energy system for integrating of renewable components, ensuring good stability, maximizing the operating range, and minimizing the investment costs should be critically evaluated in the future works. • Designing tools and key criteria for smart renewable energy systems. • Efficiency and prospect of integrating renewables into energy system for smart city. • Existing problems and challenges for renewable-based energy system in smart city. • Future scenarios for the sustainable development of energy system in smart city. [ABSTRACT FROM AUTHOR]

Renewable energy is one of the fastest growing segments of energy consumption and wind energy is one of the most widely used sources of renewable energy. There is, however, much less known about the main drivers of wind energy consumption at the country level. This paper uses the logarithmic mean Divisia index (LMDI) method to study the driving factors in wind energy consumption for a group of 17 countries (Australia, Canada, China, Denmark, France, Germany, Greece, India, Ireland, Italy, Japan, Netherlands, Portugal, Spain, Sweden, United Kingdom, and the United States) that are major consumers of wind energy. The renewable energy share component has the largest impact on wind energy consumption. Improvements in energy intensity are the largest driver of reductions in wind energy consumption. Wind energy consumption forecasts for each country in the business as usual (BAU) scenario for the years 2018–2025 show that compound annual growth rates (CAGRs) for wind energy consumption are highest for Canada, Sweden, China, and Germany. Countries that have high shares of renewable energy like Spain, Portugal, and Denmark have low forecast values of CAGRs. Wind energy forecasts are also calculated for a high growth rate scenario and a low growth rate scenario. Future increases in wind energy consumption are going to depend upon the continued increase in renewable energy share which in turn is affected by energy policy designed to promote fuel switching from fossil fuels to renewables. [ABSTRACT FROM AUTHOR]

While the economic is rapidly developing, human beings are facing a serious ecological problems, sustainable-development has got attention from more and more countries and has been treated as an economic and social development strategy. The development and utilization of renewable energy can realize the transformation of regional economic development mode and promote the long-term sustainable development of regional economy. One of the latest concepts that has attracted a lot of attention in the power systems is the energy hub (EH). In this paper, a combined energy system (CES) known as the EH consisting of electrical, cooling and heating equipment along with the demand response programs (DRPs) as well as renewable energy resources (RERs) optimization study have been proposed. Moreover, the uncertainty modeling and electrical scenario creation of cooling, heating, wind speed, solar irradiation and the energy carriers prices including electricity and natural gas is presented. The objective of the optimization problem is maximizing the profit of the EH with the existence of DRPs and RERs under four scenarios which is solved by enhanced grey wolf optimization (GWO) algorithm. In order to avoid such deficiencies and to realize a stabilized relationship between exploration and exploitation, a new modified grey wolf optimization (MGWO) algorithm is proposed. The implementation results show high accuracy and power levels of this method to solve the aforementioned problem under different uncertain parameters and various scenarios. The simulation results of proposed EH profit maximization model shows a reduction in purchased electricity from the main grid and a reduction of the overall operation costs. [ABSTRACT FROM AUTHOR]