As a clean form of energy utilization, wind power is important for alleviating climate change. Although no direct carbon emissions occur in wind power generation, there exist upstream carbon emissions from manufacturing and installation, which have indirect effects on both the locations of wind farms and areas involved in upstream production and manufacturing. In this paper, based on Input−Output based Life Cycle Analysis (IO-LCA), we explored the lifetime carbon emissions of 378 wind farms in China that were still in operation in 2015. The regional distributions of carbon emissions from wind farms during the whole lifetime were depicted. The embodied carbon emission transfers from the location of the wind farm operation to upstream turbine manufacturing regions were traced. The net emission reduction benefits among regions were also calculated. Results show that carbon emissions mainly distribute in Liaoning, Inner Mongolia, and Tianjin in the turbine manufacturing stage, with a total... [more]

A control structure design of a three-phase three-leg four-wire grid-tied Distribution Static Synchronous Compensator (DSTATCOM) based on a combined-step-size real-coefficient improved proportionate affine projection sign algorithm (CSS-RIP-APSA) has been presented. The three-phase four-wire DSTATCOM is used for reactive power compensation along with harmonic current minimization. This strategy also helps in load balancing and neutral current compensation. The affine projection sign algorithm (APSA) is a member of the adaptive filter family, which has a slow convergence rate. The conventional adaptive filter deals with the trade-off between the convergence rate and the steady-state error. In the proposed algorithm, the RIP-APSA adaptive filter with two different step sizes has been designed to decrease the computational burden while achieving the advantages of a fast convergence rate and reduced steady-state error. The proposed controller also makes the inverter function a shunt compen... [more]

The Dongsha Island (DS) is located in the mid-northern South China Sea continental margin. The waters around it are underlain by the Chaoshan Depression, a relict Mesozoic sedimentary basin, blanketed by thin Cenozoic sediments but populated with numerous submarine hills with yet less-known nature. A large hill, H110, 300 m high, 10 km wide, appearing in the southeast to the Dongsha Island, is crossed by an ocean bottom seismic and multiple channel seismic surveying lines. The first arrival tomography, using ocean bottom seismic data, showed two obvious phenomena below it: (1) a low-velocity (3.3 to 4 km/s) zone, with size of 20 × 3 km2, centering at ~4.5 km depth and (2) an underlying high-velocity (5.5 to 6.3 km/s) zone of comparable size at ~7 km depth. MCS profiles show much-fragmented Cenozoic sequences, covering a wide chaotic reflection zone within the Mesozoic strata below hill H110. The low-velocity zone corresponds to the chaotic reflection zone and can be interpreted as of h... [more]

With the development of autonomous driving technology, the requirements for machine perception have increased significantly. In particular, camera-based lane detection plays an essential role in autonomous vehicle trajectory planning. However, lane detection is subject to high complexity, and it is sensitive to illumination variation, appearance, and age of lane marking. In addition, the sheer infinite number of test cases for highly automated vehicles requires an increasing portion of test and validation to be performed in simulation and X-in-the-loop testing. To model the complexity of camera-based lane detection, physical models are often used, which consider the optical properties of the imager as well as image processing itself. This complexity results in high efforts for the simulation in terms of modelling as well as computational costs. This paper presents a Phenomenological Lane Detection Model (PLDM) to simulate camera performance. The innovation of the approach is the modell... [more]

Power generation, distribution, transmission, and consumption face ongoing challenges such as smart grid management, control, and operation, resulting from high energy demand, the diversity of energy sources, and environmental or regulatory issues. This paper provides a comprehensive overview of blockchain-based solutions for smart grid management, control, and operations. We systematically summarize existing work on the use and implementation of blockchain technology in various smart grid domains. The paper compares related reviews and highlights the challenges in the management, control, and operation for a blockchain-based smart grid as well as future research directions in the five categories: collaboration among stakeholders; data analysis and data management; control of grid imbalances; decentralization of grid management and operations; and security and privacy. All these aspects have not been covered in previous reviews.

As a consequence of the increasing share of renewable energies and sector coupling technologies, new approaches are needed for the study, planning, and control of modern energy systems. Such new structures may add extra stress to the electric grid, as is the case with heat pumps and electrical vehicles. Therefore, the optimal performance of the system must be estimated considering the constraints imposed by the different sectors. In this research, an energy system dispatch optimization model is employed. It includes an iterative approach for generating grid constraints, which is decoupled from the linear unit commitment problem. The dispatch of all energy carriers in the system is optimized while considering the physical electrical grid limits. From the considered scenarios, it was found that in a typical German neighborhood with 150 households, a PV penetration of ∼5 kWp per household can lead to curtailment of ∼60 MWh per year due to line loading. Furthermore, the proposed method eli... [more]

Logistics has become one of the most important economic sectors. It significantly affects the transport infrastructure and many other sectors that are crucial for the country’s development. It is the factor that also influences trade efficiency. However, the question arises if logistics performance is significant for the trade of critical goods which are energy raw products. The aim of the paper is primarily to investigate the EU energy trade flows in general and to estimate the effect of logistics performance on the international trade of energy raw products. The energy raw products are grouped into solid, liquid, and gaseous products, and separate estimates are made for their export and import. The analysis also differentiates between the trade flows, that is export and import within the EU and trade flows between EU member states and third countries. The empirical model is based on the theory of gravity model extended to include the six subcomponents of the Logistics Performance Ind... [more]

Wind direction and speed are the most important factors that determine the degree of damage caused by a jet fire. In this study, the metal hose used to extract/supply fuel was identified as the component with the highest risk for a jet fire occurring at an aerospace facility. A risk assessment was performed to evaluate the individual risk of a jet fire from the metal hose according to the wind direction and speed. HSE failure data was applied for calculating the jet fire probability including metal hose failure, ignition frequency, and jet fire frequency. Which was 3.0 × 10−4. The individual risk of different fatality probabilities was calculated according to the wind rose data for the aerospace facility. The individual risk from jet fire in the aerospace facility was calculated with a maximum risk of 3.35 × 10−5 and a minimum risk of 1.49 × 10−6. The individual risk satisfied HSE ALARP criteria. In addition, firewalls, extinguishing systems, and an emergency shut off system were enhan... [more]

This paper proposes enhanced prediction and control design methods for improving traffic flow with human-driven and automated vehicles. To achieve accurate prediction for the entire time horizon, data-driven and model-based prediction methods were integrated. The goal of the integration was to accurately predict the outflow of the traffic network, which was selected as the highway section in this paper. The proposed novel prediction method was used in the optimal design for calculating controlled inflows on highway ramps. The goal of the design was to reach the maximum outflow of the traffic network, even against disturbances on uncontrolled inflows of the network. The control design leads to an optimization problem based on the min−max principle, i.e., the traffic outflow is considered to be maximized by controlled inflows and to be minimized by uncontrolled inflows. The effectiveness of the prediction and the control methods through simulation examples are illustrated, i.e., traffic... [more]

Due to the surge in load demand, the scarcity of fossil fuels, and increased concerns about global climate change, researchers have found distributed energy resources (DERs) to be alternatives to large conventional power generation. However, a drastic increase in the installation of distributed generation (DGs) increases the variability, volatility, and poor power quality issues in the microgrid (MG). To avoid prolonged outages in the distribution system, the implementation of energy management strategies (EMS) is necessary within the MG environment. The loads are allowed to participate in the energy management (EM) so as to reduce or shift their demands to non-peak hours such that the maximum peak in the system gets reduced. Therefore, this article addresses the complication of solutions, merits, and demerits that may be encountered in today’s power system and encompassed with demand response (DR) and its impacts in reducing the installation cost, the capital cost of DGs, and total el... [more]

Previous analyses of the PV market (and the impact of the pandemic on it) have focused on the market as a whole. The literature does not contain analyses of selected services sectors (e.g., catering, hotel services) in terms of the use of photovoltaics. There are no studies that would show in which segments the demand profile for electricity most closely matches the production from photovoltaic installations (not to mention the impact of the pandemic). The authors analyzed selected service sectors (catering and hotel) in terms of the use of photovoltaics before and during the COVID-19 pandemic. The paper proposes a comparative methodology for the use of photovoltaics for self-consumption, including statistical analyses and calculations of the self-consumption index for representatives of various selected services sectors. The highest value of the self-consumption ratio at the level of 52% was shown for cafes and restaurants (during the pandemic). Surprisingly, in the pandemic, the self... [more]

This paper proposes a generic analysis framework for a grid supporting modular multilevel converter (MMC)-high voltage DC (HVDC) in a multi-infeed of line commutated converter (LCC) and MMC (MILM) system. MMC-HVDC can support the grid by compensating for the exact reactive power consumptions within the MMC-HVDC system and the varying power system conditions in the MILM system. Maximum active/reactive power capability (MPQC) curve and PQ loading curve comparison process is introduced to properly design a grid supporting MMC-HVDC. While the MPQC curve presents the maximum PQ range of the MMC-HVDC system based on the submodule capacitance value and the modulation index, the PQ loading curve presents the reactive power requirement from the power system that MMC-HVDC needs to compensate. Finally, the comparison of these two curves yields the proper value of submodule capacitance and the modulation index for sufficiently supporting the MILM system. The proposed framework is validated with de... [more]

This paper introduces the mobile battery network for electronic devices through powerbanks in a city, and proposes an optimization model to find the optimum site and set-up of the network considering costumers demand, logistics components, the batteries degradation, and terminal’s charger regime. To this end, a series of degradation tests were carried out on lithium-ion batteries, in four different charger regimes, in which the battery voltage amplitude and the charging electric current were varied. The results of these tests were incorporated into the optimization model as the depreciation rate and charge time over battery life. The mathematical modeling innovates by including new components designed specifically for this new problem: battery availability according to charging time; different types of customer service; objective function modeling that includes the logistical costs of battery relocation, terminal maintenance, and battery depreciation. The results indicate that the netw... [more]

The design of longer-lasting products, such as domestic electric appliances, is a key-stone approach of the circular economy to reduce the use of non-reusable materials and the number of wastes to be managed at the end of the product’s life as well as to extend it. The manufacturing of modern electric appliances includes the incorporation of printed circuit boards (PCBs). PCBs provide mechanical support and electrically connect electrical or electronic components using conductive trackpads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. This paper proposes a PCB maintenance framework, fully compliant with the “Right to Repair” concept, considering the impact of their aging failures based on measurements made on them, as well as the repair and replacement costs of their components. Herein, we present an algorithm that assesses the problem of handling the repair and replacement cost corresponding... [more]

The article presents the scope of issues related to the impact of the VUCA (volatility, uncertainty, complexity, ambiguity) environment on digital competences of management staff in power companies. Each company has to deal with its own individual and personalized VUCA world typical for the power industry. Unfortunately, some organizations are not aware of its existence, and therefore they do not identify the signals coming from the external environment while still working according to the developed patterns. The VUCA approach requires changing the competency model in enterprises and focusing on its strengths. On this basis, the research problem regarding power enterprises was formulated. The problem discussed in the article below concerns the undefined and undefined influence of the VUCA environment on the emerging digital competences of managers. In connection with the identification of the research problem in this area, an attempt was made to define the aim of the study, which is to... [more]

The aim of this design was to improve the heat transfer performance significantly due to larger turbulent region and much vortices formed by tube inserted. In this article, the BSL k-ω model was chosen as turbulence model to simulate the thermohydraulic performance of the proposed tubes inserted with rectangular winglet vortex generators (RWVGs) when the Re was set as 5000 to 15,000. The reliability of the simulation results was obtained by comparing with the empirical formulas and experimental results. By means of numerical simulation, the influence mechanism of geometric parameters of RWVGs on thermal-hydraulic performance in tubes was analyzed. And the impact of three configurational parameters on the thermal performance was studied, namely the angle α, the height H and the number N of the RWVGs, respectively. The results revealed that the capacity of heat transfer in tubes with RWVG inserts was obviously larger than that in ordinary circular tube. In addition, it could be seen... [more]

In this paper, the numerical model of a centrifugal compressor low-flow stage is verified. The gaps and labyrinth seals were simulated in the numerical model. The task was to determine the optimal settings for high-quality modeling of the low-flow stages. The intergrid interface application issues, turbulence and roughness models are considered. The obtained numerical model settings are used to validate seven model stages for the range of the optimal conditional flow coefficient with Φopt = 0.008−0.018 and the conditional Mach number Mu = 0.785−0.804. The simulation results are compared with the experimental data. The high pressure stage-7 (HPS-7) stage with Φopt = 0.010 and Mu = 0.60 at different inlet pressure of 4, 10 and 40 atm is considered separately. Acceptable validation results are obtained with the recommended numerical model settings; the modeling uncertainty for the polytropic pressure coefficient δη*pol < 4% for the efficiency coefficient δη*pol exceeds the limit of 4%... [more]

The purpose of this study is to explain the determinants of the process of investing in renewable energy sources (RES) from the perspective of enterprises, with particular emphasis on the strength of their orientation on such strategic issues as sustainable development, orientation towards innovation, as well as the level of maturity of their partnership with the client. The research method was carried out on a sample of 157 industrial enterprises in the food industry. The research process was conducted with the consideration of making these decisions dependent on the strength of companies’ commitment to several strategic issues: sustainable development, innovation orientation, and the maturity of their partnership with the customer. The results of the data analysis collected during the quantitative research show a strong correlation between the level of openness of the organization of the IR 4.0 era to RES and (a) orientation towards sustainable development, (b) orientation towards in... [more]

The determination of methane content of coal seams is conducted in hard coal mines in order to assess the state of methane hazard but also to evaluate gas resources in the deposit. In the world’s mining industry, natural gas content in coal determination is usually based on direct methods. It remains the basic method in Poland as well. An important element in the determination procedure is the gas loss that occurs while collecting a sample for testing in underground conditions. In the method developed by the authors, which is a Polish standard, based on taking a sample in the form of drill cuttings, this loss was established at a level of 12%. Among researchers dealing with the methane content of coal, there are doubts related to the procedures adopted for coal sampling and the time which passes from taking a sample to enclosing it in a sealed container. Therefore, the studies were designed to evaluate the degree of degassing of the sample taken in the form of drill cuttings according... [more]

Supercritical water gasification (SCWG) is a promising technology for the valorization of wet biomass with a high-water content, which has attracted increasing interest. Many experimental studies have been carried out using conventional heating equipment at lab scale, where researchers try to obtain insight into the process. However, heat transfer from the energy source to the fluid stream entering the reactor may be ineffective, so slow heating occurs that produces a series of undesirable reactions, especially char formation and tar formation. This paper reviews the limitations due to different factors affecting heat transfer, such as low Reynolds numbers or laminar flow regimes, unknown real fluid temperature as this is usually measured on the tubing surface, the strong change in physical properties of water from subcritical to supercritical that boosts a deterioration in heat transfer, and the insufficient mixing, among others. In addition, some troubleshooting and new perspectives... [more]

Inter-provincial power transmission in China solved the problem of electricity production and consumption spatial mismatch, which also facilitated Chinese green energy transition and sustainable development. Aiming to understand the spatial patterns and main driving factors, this paper accounted the aggregate carbon intensity per electricity produced by each province, built the inter-provincial Out−Destination matrixes of carbon emission embodied in power transmission among 27 provincial areas of 2006 and 2019, and quantitatively analyzed the change in spatial patterns of carbon flow and carbon intensity difference between power inward and outward provinces. We found that the inter-provincial power transmission has led to the reduction in the national average carbon intensity per electricity produced from 0.855 kg/kWh in 2006 to 0.628 kg/kWh in 2019 and the green energy transition of all provinces. The spatial morphology characteristics of carbon flow show the ‘three corridors of West-... [more]

The primary objective of this paper is to identify the possibilities of using sugar beet pulp as feedstock to produce a variety of added-value products. Such an application of the sugar production byproducts contributes to implementing circular bio-economy, which is a source of many economic, social, and environmental benefits. Specific objectives of this paper are: (1) Presenting the concept and meaning of circular bio-economy. (2) Characterizing properties of the sugar beet pulp from the perspective of using them as feedstock. (3) Determining the volume of production of the sugar beet pulp and the current methods of using them. (4) Determining the methods of obtaining attractive bioproducts and renewable energy from sugar beet pulp. Special attention was given to the amount of sugar beet pulp produced in Polish sugar refineries. Poland is among the European countries in which the volume of produced sugar is especially high. Therefore, the problem of appropriate waste management in th... [more]

Remote and hybrid working models and accelerated digitalization of the human resources processes were introduced in most organizations worldwide as a consequence of the COVD-19 pandemic. This digital revolution at the workplace was forced by extraordinary circumstances, thus its impact had not been anticipated before. This motivated the authors to study the new work reality. The research was based on a hypothesis that the digitalization of work and the human resources processes, approaches organizations to the sustainable development ideal. Sustainability is here understood as maintaining a balance between economic, environmental, and social factors. The authors analyzed the impact between the digital processes and the way of working on the following areas: CO2 emissions, creating plastic waste, saving energy, creating a gender-diverse and inclusive workplace. To verify the hypothesis, the authors used their own original and desk research. The original research was conducted within a B... [more]

Poland is dynamically changing its energy mix. As a result of this process, solar energy is increasing its share in energy production. The development of the solar energy market is determined by numerous factors. This paper aims to develop a roadmap for further development of the photovoltaic (PV) energy market in Poland. The scope of the research covers five areas of PV technology and market development in Poland: (i) technology; (ii) power grids; (iii) law; (iv) economic conditions; and (v) social conditions. With the use of a Technology Roadmapping Methodology (TRM), for each of the determined areas, several factors were analyzed, and their development paths were described. In addition, the article focuses on technological challenges (regarding PV cells, modules, components, power conversion and monitoring and management system, optimizers, batteries, and other energy storage systems), grid efficiency, recycling, production costs, subsidies, public awareness and education, and the e... [more]

This Special Issue titled “Advanced Wastewater Treatment and Biomass Energy” aims to compile the latest research and challenges in the field of wastewater treatment and energy production to reduce the impact of human activities on the environment [...]