As the power system undergoes continued change—widespread integration of inverter-based resources, electrification of transportation systems, decentralization, and increased digitization—the best practices for power system studies and device testing are also evolving. Electromagnetic transient (EMT) simulation is being used progressively by transmission and distribution system operators, equipment manufacturers, education and research institutions, and consultants who require a greater depth of analysis than is possible with traditional (RMS-based) system representation. Real-time simulation is becoming increasingly prevalent in the aforementioned verticals as it provides an efficient means of EMT analysis and also enables hardware-in-the-loop (HIL) testing of protection, control, and power devices. Real-time simulator manufacturers must continually develop their technology to improve the scope and accuracy of the power system components and phenomena that can be represented, the range... [more]

With the reform of the power system in China, investments in power grid projects across the whole power system are increasing. However, there are various objectives to achieve in the investment decision processes of power grid projects, so the rational investments of a grid project can be seen as a multi-objective optimization problem. Meanwhile, these issues have rarely been studied at home and abroad, and this paper will fill this gap. As a result, this study critically analyzed the application of a multi-objective optimization model to power grid investment. Firstly, the objective factors of grid investments were explored, which were quantified through quantitative methods. Secondly, based on the characteristics of power grid investment, a multi-objective optimization model was established, and the assumptions and constraints of the model were presented. Finally, NSGA-II was used for solving the multi-objective optimization model. The results show that: (1) Multi-objective optimizat... [more]

In wind energy, the accuracy of the estimation of the wind resource has an enormous effect on the expected rate of return of a project. For a given project, the wind resource assessor is faced with a difficult choice of a wide range of simulation tools and workflows with varying accuracies (or “skill”) and costs. There is currently no guideline or process available in the industry for helping with the decision of the most “optimal” choice—and this is particularly challenging in mountainous (or “complex”) terrain. In this work, a new decision process for selecting the Wind Resource Assessment (WRA) workflow that would expect to deliver the best compromise between skill and costs for a given wind energy project is developed, with a focus on complex terrain. This involves estimating the expected skill and cost scores using a set of pre-defined weighted parameters. The new process is designed and tested by applying seven different WRA workflows to five different complex terrain sites. The... [more]

Wave energy has the potential to power significant portions of economies around the world. Standard International Electrotechnical Commission methods for determining wave energy quantifies the gross wave resource available in the ocean, yet a significant portion of this resource is not usable by specific wave energy converters (WECs). This can provide a misleading assessment of the spatiotemporal opportunities for wave energy in deployment locations. Therefore, there is a need to develop a new technique to assess potential wave power from a device point of view that is generally applicable across WEC sizes. To address this challenge, a novel net power assessment methodology is proposed, which implements Budal’s upper bound (which describes the power available to a WEC based on its stroke), the radiation power limit (which describes the maximum radiation-based amount of wave power a WEC can absorb), and total gross incident wave power as absorbable power upper bounds. Spatiotemporal opp... [more]

Reducing energy consumption should be treated as crucial for contemporary information and communication technology (ICT) projects under conditions of Industry 4.0. This research proposes a wider look at the factors influencing the success of ICT industry projects, considering not only technological and procedural conditions or implementation methods but also information and competency resources, thus allowing for correct decisions to be taken during project implementation. The article analyzes the information gap in Industry 4.0 projects completed in enterprises based in Poland, following the concept of sustainable development and minimization of energy consumption. The research was completed between 2018 and 2021 in medium enterprises, and the result is a qualitative characteristic of the information gap in ICT projects from the client’s perspective. The research can help develop a complete methodology for Industry 4.0 ICT projects to limit the level of uncertainty and risk while redu... [more]

This paper presents a novel algorithm to pick PV-based pumping system operating points that simultaneously achieve maximum delivered power and optimized stability. We present an in-depth analysis of operating point dynamics and shape the PV output current and voltage parameter plans. Accordingly, we draw the power bifurcation diagram with all possible operating points. Our proposed algorithm picks the power operating point midway between two consecutive stable points and far enough from the stability boundary to assure system safety. We validated our methodology successfully by numerical simulation based on speculative evidence using MATCON/MATLAB/SimPowerSystems blocks. In addition, we compared the proposed algorithm with P&O MPPT algorithm, and the results verified the reliability of our proposed algorithm to deliver maximum stable power.

This paper demonstrates the investigation of the acquired outcomes from consistent information observing a 467.2 kWp solar photovoltaic (SPV) framework commissioned on the roofs of three separate high-rise buildings, which are located at the location of 26.9585° N and 80.9992° E. Onside real-time performance for this system was investigated for three years, 2018−2020; this system contains 1460 SPV panels of 320 Wp each, having 20 PV panels per string, 09 DC/AC power conditioning units (PCU), and a SCADA (supervisory control and data acquisition) system for monitoring the other necessary parts of a grid-interactive SPV system. The outcomes of the different buildings are compared with each other to analyze the power output at the same input conditions. Hardware components of the plants with approximately the same ratings (P2 ~ 108.8 kWp + P3 ~ 128 kWp) are compared (with P1 ~ 230.4 kWp). Simulation modeling of the year 2020 in PVsyst tool for generated energy, Performance Ratio (PR), and... [more]

Reuse, refurbishing, and recycling are the most sustainable options for handling waste materials. However, for municipal solid waste (MSW) that is highly heterogenic, crude, contaminated, and decrepit, thermal conversion in waste-to-energy (WtE) plants is an option. In such plants, the fuel quality of MSW is difficult to predict and the substantial changes expected are challenging for incineration stability. Development of new online sensor technologies for monitoring waste properties prior to incineration is therefore needed. Sensors may contribute to increase WtE process stability, as well as reducing the probability of incineration stops or emissions exceeding legal limits. In this work, the operating principles of potential sensor systems for waste monitoring are categorized and assessed to be implemented for providing parameters for process control or indicators for process alarms in the waste incineration process. For transmissive settings, the use of inductance and hard X-ray se... [more]

Smart Cities can benefit from existing municipal low voltage (LV) distribution grids by supporting public services with permanent power supply and providing grid connection points to distributed generators (DG). The increased integration of DGs and inverter based non-linear loads increases voltage quality issues, thus the cost-efficient assurance of voltage quality in LV grids with long radial lines is of increasing importance for the operators of municipal electricity distribution systems. Conventional methods for mitigating voltage quality issues (e.g., power line renovation) might not be optimal solutions either technologically or economically. Existing studies do not address all relevant issues related to the assurance of required voltage quality in such LV grids. This paper provides an overview of the applicability and rationality of traditional as well as alternative methods to solve voltage problems in LV grids. The authors use DIgSILENT PowerFactory software to simulate the per... [more]

Renewable energy sources are an alternative to traditional sources and are based on inexhaustible and environmentally friendly supply. Various controversies have been stirred up by the development of energy production from renewable sources, e.g., due to the high cost of these investments or carbon footprint at the production stage of renewable installations, or later in the disposal process. However, they seem to be gradually offset by the numerous benefits that outweigh the initial costs of their support. Therefore, it is not surprising that European Union (EU) countries are at the forefront of the transition to a low-emission economy. This is evidenced, e.g., by a 22% reduction in greenhouse gas emissions in Member States, with gross domestic product (GDP) growth of 58% between 1990 and 2017. Nevertheless, the use of renewable energy sources such as sun, wind, water, etc. is much more expensive than burning fossil fuels. This argument of high investment costs can be decisive in deci... [more]

Nowadays, energy policymakers are asked to develop strategies to ensure an affordable clean energy supply as well as minimizing investment risks. In addition, the rise of several community engagement schemes and the uptake of user-scale technologies introduce uncertainties that may result in a disruptive factor for energy systems evolution. This paper introduces a novel scenario analysis approach for local energy planning that supports policymakers and investors in prioritizing new renewable power plant investments, addressing the risks deriving from citizens’ choices. Specifically, a combined analysis is performed on the adoption trends of distributed photovoltaic systems and electric vehicles that are expected to heavily influence the evolution of energy systems. For this reason, an energy model is developed for Pantelleria island, and its transition from an oil-based energy supply to a renewable one up to 2050 is investigated. It is demonstrated how optimal-cost renewable-based scen... [more]

The perspective of reducing negative climate changes in the area of production of electricity is beneficial mainly for photovoltaic panels (PV). In this case, qualitative−ecological interactions arise, which should be verified to properly select PV. It refers to the analysis of customers’ expectations of the utility of photovoltaic panels and their impact on the landscape (environments). Therefore, the purpose of the article was to propose a model to predict the quality of photovoltaic panels considering the expectations of the customers. According to the SMART(-ER) method, the purpose of the analysis was determined. Then, using brainstorming (BM), the criteria of PV were determined in groups: technical, utility, and aesthetic. The customer expectations were then obtained by questionnaire with the technique with the method of comparison in pairs and Likert scale. Customer expectations were initially verified using the AHP method, after which the key PV criteria of PV were selected. The... [more]

Thermal comfort is one of the most important factors for occupant satisfaction and, as a result, for the building energy performance. Decentralized heating and cooling systems, also known as “Personal Environmental Comfort Systems” (PECS), have attracted significant interest in research and industry in recent years. While building simulation software is used in practice to improve the energy performance of buildings, most building simulation applications use the PMV approach for comfort calculations. This article presents a newly developed building controller that uses a holistic approach in the consideration of PECS within the framework of the building simulation software Esp-r. With PhySCo, a dynamic physiology, sensation, and comfort model, the presented building controller can adjust the setpoint temperatures of the central HVAC system as well as control the use of PECS based on the thermal sensation and comfort values of a virtual human. An adaptive building controller with a wide... [more]

In light of the increasing demand for energy sources in the world and the need to meet climate goals set by countries, there is growing global interest in high temperature gas cooled reactors (HTGRs), especially as they are known to be inherently safe nuclear reactors. The safety of HTGRs results, among other, from the nature of the nuclear fuel used in them in the form of coated TRISO particles (tri-structural-isotropic) and the reduction of the total amount of radioactive waste generated. This paper reviews numerous methods used to ensure the sustainable, feasible management and long-term storage of HTGR nuclear waste for the protection of the environment and society. The types of waste generated in the HTGR cycle are presented as well as the methods of their characterization, which are important for long-time storage and final disposal. Two leading nuclear fuel cycle strategies, the once-through cycle (direct disposal or open cycle) and the twice-through cycle (recycling or partiall... [more]

With the gradual popularization of hydrogen fuel cell vehicles (HFCVs), the construction and planning of hydrogen refueling stations (HRSs) are increasingly important. Taking operational HRSs in China’s coastal and major cities as examples, we consider the main factors affecting the site selection of HRSs in China from the three aspects of economy, technology and society to establish a site selection evaluation system for hydrogen refueling stations and determine the weight of each index through the analytic hierarchy process (AHP). Then, combined with fuzzy comprehensive evaluation (FCE) method and artificial neural network model (ANN), FCE method is used to evaluate HRS in operation in China’s coastal areas and major cities, and we used the resulting data obtained from the comprehensive evaluation as the training data to train the neural network. So, an intelligent site selection model for HRSs based on fuzzy comprehensive evaluation and artificial neural network model (FCE-ANN) is p... [more]

In this study, we developed the design process and optimization of structural parameters of a new low-NOx burner based on low-NO combustion technology and the flame stabilization principle. Firstly, on the basis of the two-stage swirl burner, we applied the fuel-graded combustion technology and introduced the central nozzle structure to explore the influence law of graded combustion on NO emissions. Secondly, on the previously optimized structure, the matching law between the first- and second-stage cyclone blades is analyzed to obtain the optimum structural design solution for heat exchange efficiency and flame front length. Finally, a new conical blunt structure is introduced in conjunction with the flame stabilization principle, and we discuss the effects of different half cone angles on the flame stabilization, flame front length, and heat exchange efficiency of the burner. The research in this paper provides a reliable direction for the design optimization of low-NOx burners.

In this paper, we looked at the role of electromechanical storage in railway applications. A mathematical model of a running train was interfaced with real products on the electromechanical storage market supposed to be installed at the substation. Through this simulation, we gathered data on the recoverable energy of the system, its advantages, and its limitations. Various storage powers were run along variations in speed and gradient to paint a clearer picture of this application. Throughout these simulations, the energy savings were between 25% and 38%, saving up to 0.042 kWh/(seat km).

In this paper, two design optimisation methods are evaluated using gradient-based optimisation for electric vehicle traction applications. A driving cycle-based approach is used to evaluate specific operational points for the design optimisation procedure. To determine the operational points, an energy centre of gravity (ECG) approach is used. Both optimisation methods are described, namely the point based method and the flux mapping method, with a focus on the flux mapping procedure. Within the flux mapping approach, an inner optimisation loop is defined in order to maintain the stability of gradient calculation for the gradient-based optimisation. An emphasis is placed on the importance of how the optimisation problem is defined, in terms of the objective function and constraints, and how it affects a gradient based optimisation. Based on a design case study conducted in the paper, it is found that the point-based strategy realised motor designs with a slightly lower overall cost (5.... [more]

A single-cylinder marine diesel engine was modified to be operated in reactivity controlled compression ignition (RCCI) combustion mode. The engine fueling system was upgraded to a common rail fuel injection system. Natural gas (NG) was used as port fuel injection, and a diesel/sunflower methyl ester biodiesel mixture was used for direct fuel injection. The fraction of biodiesel in the direct fuel injection was changed from 0% (B0; 0% biodiesel and 100% diesel) to 5% (B5) and 20% (B20) while keeping the total energy input into the engine constant. The objective was to understand the impacts of the increased biodiesel fraction on the combustion characteristics and stability, emissions, and knocking/misfiring behavior, keeping all other influential parameters constant. The results showed that nitrogen oxides (NOx) emissions of B5 and B20 without the need for any after-treatment devices were lower than the NOx emission limit of the Euro VI stationary engine regulation. B5 and B20 NOx emis... [more]

This paper presents an unsteady flow analysis of a 3D wing with a morphing trailing edge flap (TEF) and a seamless side-edge transition between the morphed and static parts of a wing by introducing an unsteady parametrization method. First, a 3D steady Reynolds-averaged Navier−Stokes (RANS) analysis of a statically morphed TEF with seamless transition is performed and the results are compared with both a baseline clean wing and a wing with a traditional hinged flap configuration at a Reynolds number of 0.7 × 106 for a range of angles of attack (AoA), from 4° to 15°. This study extends some previous published work by examining the inherent unsteady 3D effects due to the presence of the seamless transition. It is found that in the pre-stall regime, the statically morphed wing produces a maximum of a 22% higher lift and a near constant drag reduction of 25% compared with the hinged flap wing, resulting in up to 40% enhancement in the aerodynamic efficiency (i.e., lift/drag ratio). Second,... [more]

This article reports on the influence of resorcinol (RC) on the kinetics of underpotential deposition of hydrogen (UPD of H) and the oxygen evolution reaction (OER), studied on a polycrystalline Pt electrode in a 0.5 M sulphuric acid supporting solution. It is well known that both PEM fuel cells and water electrolysers’ electrodes often contain significant amounts of nanostructured Pt or other types of noble metal particles. These materials provide the superior catalytic activity of electrochemical reactions such as OER (oxygen evolution reaction), HER (hydrogen evolution reaction) and ORR (oxygen reduction reaction). The trace amounts of phenolic substances contained in air or water could be harmful (when in contact with a fuel cell/water electrolyser’s working environment) to the abovementioned catalytic surfaces. Hence, they could potentially have severe detrimental effects on the kinetics of these processes. The results obtained in this work provided evidence for the detrimental ro... [more]

This paper studies the problem of fault detection for continuous time linear switched systems in the presence of disturbance. For this purpose, a fault detection sliding mode observer approach is designed to generate the residual signal. To minimize the effect of disturbance from the residual, the problem is formulated into H∞ filtering technique to increase more robustness. To deal with the issue of the switched systems stability, the Lyapunov-Krasovskii functional method is utilized along with average dwell time, and linear matrix inequalities are formulated to derive the sufficient conditions. The residual signal is evaluated, and an adaptive threshold is computed for both modes of the switched system. Finally, a simulation example for a case study of boost converter and a numerical example with both abrupt and incipient faults are illustrated to prove the efficacy of the proposed method.

The increasing demand for energy and commodities has led to escalating greenhouse gas emissions, the chief of which is represented by carbon dioxide (CO2). Blue hydrogen (H2), a low-carbon hydrogen produced from natural gas with carbon capture technologies applied, has been suggested as a possible alternative to fossil fuels in processes with hard-to-abate emission sources, including refining, chemical, petrochemical and transport sectors. Due to the recent international directives aimed to combat climate change, even existing hydrogen plants should be retrofitted with carbon capture units. To optimize the process economics of such retrofit, it has been proposed to remove CO2 from the pressure swing adsorption (PSA) tail gas to exploit the relatively high CO2 concentration. This study aimed to design and numerically investigate a vacuum pressure swing adsorption (VPSA) process capable of capturing CO2 from the PSA tail gas of an industrial steam methane reforming (SMR)-based hydrogen p... [more]

The current energy prices do not include the environmental, social, and economic short and long-term external effects. There is a gap in the literature on the decision-making model for the energy transition. True Cost Accounting (TCA) is an accounting management model supporting the decision-making process. This study investigates the challenges and explores how big data, AI, or blockchain could ease the TCA calculation and indirectly contribute to the transition towards more sustainable energy production. The research question addressed is: How can IT help TCA applications in the energy sector in Europe? The study uses qualitative interpretive methodology and is performed in the Netherlands, Germany, and Poland. The findings indicate the technical feasibilities of a big data infrastructure to cope with TCA challenges. The study contributes to the literature by identifying the challenges in TCA application for energy production, showing the readiness potential for big data, AI, and blo... [more]

During recent years, emissions reduction has been tightened worldwide. Therefore, there is an increasing demand for electric vehicles (EVs) that can meet emission requirements. The growing number of new EVs increases the consumption of raw materials during production. Simultaneously, the number of used EVs and subsequently retired lithium-ion batteries (LIBs) that need to be disposed of is also increasing. According to the current approaches, the recycling process technology appears to be one of the most promising solutions for the End-of-Life (EOL) LIBs—recycling and reusing of waste materials would reduce raw materials production and environmental burden. According to this performed literature review, 263 publications about “Recycling of Lithium-ion Batteries from Electric Vehicles” were classified into five sections: Recycling Processes, Battery Composition, Environmental Impact, Economic Evaluation, and Recycling & Rest. The whole work reviews the current-state of publications dedi... [more]