The conversion to renewable energy can be achieved when cities and communities start to depend on sustainable resources capable of providing for the basic needs of the community, along with a reduction in the daily problems and issues that people face. These issues, such as poverty, hunger, sanitation, and economic difficulties are highlighted in the Sustainable Development Goals (SDGs), which aim to limit and eradicate these problems along with other environmental obstacles including climate change and Greenhouse Gases (GHGs). These SDGs, containing 17 goals target each sector and provide propositions to solve such devastating problems. Hydrogen contributes to the targets of these sustainable developments, since through its implementation in different industries the levels of GHG will drop and thus contribute to the climate change which Earth is facing. Further, through the usage of such resources, many job opportunities will also be developed, thus enhancing the economy, and lifting... [more]

The area of a Microgrid (μG) is a very fast-growing and promising system for overcoming power barriers. This paper examines the impacts of a microgrid system considering Electric Vehicle Grid Integration (EVGI) based on stochastic metaheuristic methods. One of the biggest challenges to slowing down global climate change is the transition to sustainable mobility. Renewable Energy Sources (RESs) integrated with Evs are considered a solution for the power and environmental issues needed to achieve Sustainable Development Goal Seven (SDG7) and Climate Action Goal 13 (CAG13). The aforementioned goals can be achieved by coupling Evs with the utility grid and other RESs using Vehicle-to-Grid (V2G) technology to form a hybrid system. Overloading is a challenge due to the unknown number of loads (unknown number of Evs). Thus, this study helps to establish the system impact of the uncertainties (arrival and departure Evs) by proposing Stochastic Monte Carlo Method (SMCM) to be addressed. The mai... [more]

The electric power industry is one of the major industries in terms of carbon dioxide (CO2) emissions, and it is necessary to explore low-carbon green power generation models. In recent years, more research has focused on the difference in carbon emissions in fossil energy versus renewable energy but ignored the impact of energy on human well-being. The life cycle assessment (LCA) method is a better method for assessing the impact of the low-carbon model on human well-being. In this paper, the carbon footprints of coal power plants and photovoltaic power (PV) plants generating 1 Kilowatt hour (kWh) of electricity are compared to analyze the degree of carbon emissions at different stages of the two models, and the environmental impact potential of the two models is analyzed using the LCA method. The differences between the two models in terms of human well-being were analyzed through questionnaires and quantified using the hierarchical analysis method. The impact of the different models... [more]

Solar energy is a long-established technology, which has zero CO2 emissions, and provides low-cost energy for a given area of land. The concentrator photovoltaic (CPV) has been given preference over the photovoltaic due to its high efficiency. In a CPV system, most of the solar cell area has been replaced with an optical concentrator. Various parabolic trough based CPV systems have been presented where a concentration of <300 is achieved. In the current research, a design is presented to achieve a high concentration of 622×. The design consists of two stages of concentration including parabolic trough as a main concentrator and nonimaging reflective grooves as a secondary concentrator. The trough reflects the incident light towards the secondary reflector where the light is redirected over the solar cell. Design of the two-stage concentrator, ray-tracing simulation, and results are presented. The system achieved an optical efficiency of 79%. The system would also be highly acceptabl... [more]

The replacement of hydrocarbon fuels by ammonia in industrial systems is challenging due to its low burning velocity, its narrow flammability range, and a large production of nitric oxide and nitrogen dioxide when burned close to stoichiometric conditions. Cracking a fraction of ammonia into hydrogen and nitrogen prior to injection in the combustion chamber is considered a promising strategy to overcome these issues. This paper focuses on evaluating how different levels of ammonia cracking affect the overall burning velocity, the lean blow-off limit, the concentration of nitric oxide and nitrogen dioxide, and the flame response to acoustic perturbations. Swirl stabilized premixed flames of pure ammonia−air and ammonia−hydrogen−nitrogen−air mixtures mimicking 10%, 20%, and 28% of cracking are experimentally investigated. The results show that even though ammonia cracking is beneficial for enhancing the lean blow-off limit and the overall burning velocity, its impact on pollutant emissio... [more]

Carbon emissions reduction is crucial to global climate governance and sustainable development. By 2060, China envisioned being carbon-neutral, and it has adopted a series of policies and measures for environmental management, especially in the main stream of Yangtze River basin, where China’s carbon emissions are centered. The spatial distribution characteristics and agglomeration effects of carbon dioxide (CO2) emissions in the main stream of Yangtze River basin are analyzed from 2010 to 2019 based on the perspective of local (city and state) administrative regions, and uses the spatial Durbin model to examine the influencing factors and spatial spillover effects of carbon emissions. The findings discovered from the extensive research are as follows: First, carbon emissions in the main stream of Yangtze River basin present a fluctuating upward trend, and CO2 emissions in the lower reaches are significantly higher than those in the middle and upper reaches, which are closely related t... [more]

In this work, we have studied how the vertical illuminance of the human eye position, illuminance of the horizontal work surface, and the brightness of the computer screen in the office space lighting are correlated under an energy-saving environment. This investigation was conducted in a full-scale laboratory that simulates an office space with 20 adults. It was found that when the indoor ambient lighting illuminance changes, the vertical illuminance of the subject’s eye position is affected accordingly, and the two factors are strongly correlated. On the other hand, when the surrounding environment is brighter and the vertical illuminance increases, the illuminance of the horizontal working surface adjusted by the subject during the visual display terminal (VDT) operation is significantly reduced. The horizontal illuminance value can even be lower than the value frequently employed in various countries around the world, since the computer screen brightness will be adjusted accordingl... [more]

The process of looking for alternative energy sources is driven by the increasing demand for energy and environmental contamination caused by using fossil fuels. Recent investigations reported the efficiency of microalgae for biofuel production due to its low cost of production, high speed of growth, and ability to grow in harsh environments. In addition, many microalgae are photosynthetic, consuming CO2 and solar light to grow in biomass and providing a promising bioenergy source. This review presents the recent advances in the application of microalgae for biofuel production. In addition, cultivation and harvesting systems and environmental factors that affect microalgae cultivation for biofuel production have also been discussed. Moreover, lipid extraction and conversion technologies to biofuel are presented. The mixotrophic cultivation strategy is promising as it combines the advantages of heterotrophy and autotrophy. Green harvesting methods such as using bio-coagulants and floccu... [more]

Climate change and natural disasters have brought threats to humanity greater than ever. The built environment is a critical part of the climate action plan in terms of its resilience and sustainability. The growing awareness of sustainability in the built environment has led to the increased uptake of sustainable buildings and infrastructure projects. However, a growing number of studies reported some forms of performance gaps in achieving sustainability, in which the actual outcomes and performance of buildings were far from the expected goals. Researchers started to question the alleged benefits of the sustainable built environment. Apart from being overoptimistic in setting the environmental goals, some studies suggested that the gaps could arise from a negligence of the interplay between humans and the environment for delivering the sustainability goals. Hence, this paper intends to highlight opportunities in optimizing sustainability performance in the built environment via human... [more]

The classic Photovoltaic system maximum power point tracking technique cannot concurrently take into account the dynamic response speed and steady-state accuracy when the light intensity changes. To address this issue, a new composite variable step MPPT control algorithm is developed in this study. Based on the three-stage variable step incremental conductance method, the algorithm adds the Kalman filtering algorithm to pre-process the photovoltaic cells output signal, and uses a new calculation approach to adjust the variable step coefficient. As a result, the perturbation step can be automatically modified according to changes in the external environment, which resolves the issues with poor dynamic reaction speed when the classic variable step algorithm started and the light changed. Compared to conventional MPPT control algorithms, the improved MPPT strategy can be easily realized using a hardware control system since it has a simplified control logic and requires less data to be ca... [more]

The field of solar photovoltaic (PV) plants has seen significant growth in recent years, with an increasing number of installations being developed worldwide. However, despite advancements in technology and design, the impact of shading on the performance of PV plants remains an area of concern. Accurate 3D models produced using unmanned aerial vehicle (UAV) photogrammetry can provide aid to evaluate shading from nearby surroundings and to determine the potential of a site for electricity production via solar PV plants. The main objective of this paper is to address the problem of shadows significantly reducing energy yield in solar PV plants by proposing a methodology that aims at assessing the shading effects on PV systems and determining the optimal configuration for a PV module array using an accurate digital environment 3D model built using UAV photogrammetry. A high-level-of-detail 3D model allows us to evaluate possible obstacles for PV module array construction and accurately r... [more]

The paper describes a new, proprietary method of HS extraction from digested sewage sludge. HS was extracted using the processes of dissolving organic substances and precipitating mineral micropollutants. The obtained substances were tested by determining their IR spectrum, elemental composition, and content of micropollutants and comparing them with HS obtained using the classical method. Using Phytotestkit, it was shown that HSs isolated from digested sewage sludge contain relatively large amounts of the nutrients necessary for plants (including N and P) and are a good component of a biostimulating substance. The obtained HS contains more ammonium and phosphorus ions. During extraction, inorganic impurities (including heavy metals) are reduced, and the humic product does not contain pathogens, parasites, and their spores. The method is simple, economically justified, and can be used on an industrial scale.

The aim of the presented research was the assessment of phosphorus speciation impact on the precipitation of phosphorus in reject water using Ca(OH)2. To achieve this, phosphorus speciation (organic and inorganic phosphorus in suspension and in dissolved form) in reject water that is produced during sludge dewatering, after methane digestion in wastewater treatment plants (WWTPs), was determined. This study covered the materials from four WWTPs with different compositions of feedstock for anaerobic digestion (AnD). In one, the AnD process of primary and secondary sludge was carried out without co-substrate, while in three others, co-substrate (waste from the agri-food industry and external waste-activated sludge and fats from industrial plants) was examined. The investigation was conducted in batch reactors using doses of Ca(OH)2 ranging from 2500 to 5500 mg Ca/dm3. The percentage of phosphorus forms determined in the raw reject water was similar, with the dominant form being soluble r... [more]

Students require a comfortable thermal environment for better academic learning and health in general. In Nepal, the majority of school buildings are constructed using local materials, but little consideration is provided to the thermal environment required for comfort. Therefore, this study demonstrates the advantages of using passive design measures through a simulation that can be used either in the early stages or as a retrofit to determine how the building performs in terms of comfort and the thermal environment. First, the thermal environment of school buildings and thermal comfort of students were evaluated through field surveys. Subsequently, a simulation was performed to investigate the operative temperatures in the classroom of a school building in Kathmandu. DesignBuilder software was used to create the base model and the simulated operative temperature was validated using the measured globe temperature. Subsequently, passive strategies, such as natural ventilation, insulati... [more]

Sustainable campus management includes energy-saving measures and waste reduction and has become important to many universities, being part of the institution’s societal responsibility. Smart energy systems (SESs), as part of campus energy management, can bring many benefits, including increased efficiency, reduced energy consumption, reduced emissions, increased reliability, and real-time control, and facilitate the integration of the renewable energy systems (RES). Despite the growing interest in energy efficiency and for the initiatives and projects to implement SESs, there are no universally accepted standards for assessing the performance of SESs, with most techniques being dedicated to subsystems. A KPI (key performance indicator) framework for evaluating the SESs’ performance from university campuses is proposed, starting from the current findings and priorities from the scientific literature, energy standards, legislation, and university rankings. The framework can support the... [more]

In China, one of the most pressing issues that have to be addressed is how to best manage the link between energy consumption and sustainable development. Given this context, the goal of the current article is to investigate the effect of renewable energy consumption on sustainable development. Using provincial panel data from 2005 to 2020 and the province and year fixed effects model for an empirical study, we discover that renewable energy consumption has a favorable impact on sustainable development. Similarly, the findings suggest the influence of non-renewable energy consumption on sustainable development is weaker than that of renewable energy consumption. Moreover, the heterogeneity of the influence of renewable energy consumption and nonrenewable energy consumption on sustainable development in eastern, central, and western China has been demonstrated as well. Notably, the two-stage least squares approach and generalized system method of moments are utilized to examine the robu... [more]

Electronic devices are commonly used for exploiting and extracting shale oil in deep downhole environments. However, high−temperature−and−pressure downhole environments jeopardize the safe operation of electronic components due to their severe thermal conditions. In the present study, an active thermal−insulation system is proposed, which consists of a spiral annular cooling plate (ACP), a thermal storage container with phase−change material (PCM) and an aerogel mat (AM). The effect of the ACP’s structure, layout and working−medium flowrate on the heat−protection performance were experimentally measured; temperature−control capability and system−operating time were used as the criteria. The results show that the AM layer is necessary and that the inner−ACP case displays better thermal−protection performance. Next, a dimensionless temperature−control factor (TCF) was proposed to evaluate the trade−off between temperature control and the system’s operating time. Note that the TCF of the... [more]

Climate change has made the decarbonization of the different domestic economies a widely accepted and urgent priority. Yet, this is a very challenging task in a largely uncharted territory. In this context, in this paper, we address the issue of energy taxation reform with an environmental focus in Portugal. We do so using a multi-sector and multi-household dynamic computable general equilibrium model of the Portuguese economy. We analyze the environmental, macroeconomic, and distributional effects of different policies replacing current energy taxation with carbon taxation and, then, extend the carbon taxation to the levels necessary to achieve the IPCC 2018 emissions reduction targets. Our analysis indicates a clear path in the quest for decarbonization. First, replace energy taxes with a carbon tax; second, adopt the levels of carbon taxation necessary to achieve the emissions goals; third, use extra tax revenues from the carbon tax to reverse any potential adverse macroeconomic and... [more]

Combined heat and power (CHP) plants have opportunities to work as distributed power generation for providing heat and power demand. Furthermore, CHP plants contribute effectively to overcoming the intermittence of renewable energy sources as well as load dynamics. CHP plants need optimal solution(s) for providing electrical and heat energy demand simultaneously within the smart network environment. CHP or cogeneration plant operations need appropriate techno-economic dispatching of combined heat and power with minimising produced energy cost. The interrelationship between heat and power development in a CHP unit, the valve point loading effect, and forbidden working regions of a thermal power plant make the CHP economic dispatch’s (CHPED) objective function discontinuous. It adds complexity in the CHPED optimisation process. The key objective of the CHPED is operating cost minimisation while meeting the desired power and heat demand. To optimise the dispatch operation, three different... [more]

Sustainable development has positioned itself as a fundamental element of a transversal nature, being linked to the energy transition. In this sense, it must be included as a mainstream objective of all actions and strategies developed at the social, academic, business, and political levels. However, to the best of our knowledge, no bibliometric work has been carried out to date to analyze the main contributions to the literature focused on the concepts of renewable energy and sustainable development. The main aim of this paper is to establish the key trends and academic contributions made in the field of renewable energies and sustainable development. For this purpose, a bibliometric and co-citation analysis has been carried out using the Bibliometrix® tool, an open-source R package. The results show that this is a field of study that has significantly increased its importance in recent years, which is illustrated using different indicators. We conclude that research trends seem to be... [more]

Fuel and oil spills during the exploration, refining, and distribution of oil and petrochemicals are primarily responsible for the accumulation of organic pollutants in the environment. The reduction in contamination caused by hydrocarbons, heavy metals, oily effluents, and particulate matter generated by industrial activities and the efficient recovery of oil at great depths in an environmentally friendly way pose a challenge, as recovery and cleaning processes require the direct application of surface-active agents, detergents, degreasers, or solvents, often generating other environmental problems due to the toxicity and accumulation of these substances. Thus, the application of natural surface-active agents is an attractive solution. Due to their amphipathic structures, microbial surfactants solubilize oil through the formation of small aggregates (micelles) that disperse in water, with numerous applications in the petroleum industry. Biosurfactants have proven their usefulness in s... [more]

Dust emissions must be managed and reduced as much as possible to safeguard the environment and human health. Plate-type electrostatic precipitators have been used to decrease pollution in a number of sectors, particularly for applications needing massive volumes of gas to be dedusted at high dust concentrations and temperatures. This paper examines large-capacity plate-type electrostatic precipitators with three sections used in a coal-fired thermal power plant. Using simulations and experiments, the collection efficiency (in different ways of supplying sections, without and with sections rapping), the influence of dust resistivity and a dust layer on the surfaces of collection electrodes, the electrical parameters (voltage, current density, and space charge density) for the sections of the electrostatic precipitators, and the electrical parameters of the power sources (voltage, current, power, and power factor) are studied. A higher dust resistivity will cause a change in the shape o... [more]

Smart grids have introduced several key concepts, including demand response, prosumers—active consumers capable of producing, consuming, and storing both electrical and thermal energies—retail market, and local energy markets. Preserving data privacy in this emerging environment has raised concerns and challenges. The use of novel methods such as online learning is recommended to address these challenges through prediction of the behavior of market stakeholders. In particular, the challenge of predicting prosumers’ behavior in an interaction with retailers requires creating a dynamic environment for retailers to set their optimal pricing. An innovative model of retailer−prosumer interactions in a day-ahead market is presented in this paper. By forecasting the behavior of prosumers by using an online learning method, the retailer implements an optimal pricing scheme to maximize profits. Prosumers, however, seek to reduce energy costs to the greatest extent possible. It is possible for p... [more]

By trapping CO2 and storing it in matured and depleted geological formations, atmospheric CO2 release can be reduced. Carbon capture and storage on a large scale can help to stabilize atmospheric greenhouse gas emissions. This can be achieved by using anthropogenic CO2 for enhanced oil recovery (EOR), which encourages advances in secure CO2 storage while enhancing the oil production process. This interaction is expected to hasten the development of CO2 storage technology and lower emissions from oil producing operations. Reducing CO2 mobility in the reservoir is crucial to achieving this goal as effectively as possible, and in situ foam generation offers a viable solution. It has been shown that implementing a blend of CO2 and foaming solution considerably reduces CO2 mobility and front propagation. Although there have been a few reviews of carbon capture, utilization, and storage (CCUS), none of these have concentrated on the role of foam EOR in achieving carbon neutrality. Therefore,... [more]

The providers of transport services in ports must ensure there is adequate protection of the quays against the hulls of vessels. Highly elastic fenders mounted on the wharfs or on the hulls of vessels are used to absorb the energy of an impact. The structure of the fender, and the highly elastic material used to make it, are designed to ensure the highest possible absorption energy with minimized reaction force. In this work, the efficiency of energy absorption by cylindrical fenders into which additional structural elements were introduced in the form of holes of various diameters, was determined numerically using the finite element method. It was found that the features of such structural elements affect the efficiency of their energy absorption. In order to confirm the accuracy of the numerical calculations, they were verified based on experimental determination of the functional parameters of the cylindrical fenders. The reaction force and absorption energy values determined numeri... [more]