The environment is seriously threatened by the rising energy demand and the use of conventional energy sources. Renewable energy sources including hydro, solar, and wind have been the focus of extensive research due to the proliferation of energy demands and technological advancement. Wind energy is mostly harvested in coastal areas, and little work has been done on energy extraction from winds in a suburban environment. The fickle behavior of wind makes it a less attractive renewable energy source. However, an energy storage method may be added to store harvested wind energy. The purpose of this study is to evaluate the feasibility of extracting wind energy in terms of hydrogen energy in a suburban environment incorporating artificial intelligence techniques. To this end, a site was selected latitude 33.64° N, longitude 72.98° N, and elevation 500 m above mean sea level in proximity to hills. One year of wind data consisting of wind speed, wind direction, and wind gust was collected a... [more]

Solar energy currently plays a significant role in supplying clean and renewable electric energy worldwide. Harnessing solar energy through PV plants requires problems such as site selection to be solved, for which long-term solar resource assessment and photovoltaic energy forecasting are fundamental issues. This paper proposes a fast-track methodology to address these two critical requirements when exploring a vast area to locate, in a first approximation, potential sites to build PV plants. This methodology retrieves solar radiation and temperature data from free access databases for the arbitrary division of the region of interest into land cells. Data clustering and probability techniques were then used to obtain the mean daily solar radiation per month per cell, and cells are clustered by radiation level into regions with similar solar resources, mapped monthly. Simultaneously, temperature probabilities are determined per cell and mapped. Then, PV energy is calculated, including... [more]

In 2019, Chile generated 20 million tons of waste, 79% of which was not properly disposed of, thereby providing an attractive opportunity for energy generation in advanced thermochemical conversion processes. This study presents a techno-economic and environmental assessment of the implementation of Waste-Integrated Gasifier-Gas Turbine Combined Cycle (WIG-GTCC) technology as an alternative for Municipal Solid Waste (MSW) treatment. The studied case assesses the conversion of 14.61 t·h−1 of MSW, which produces a combustible gas with a flow rate of 34.2 t·h−1 and LHV of 5900 kJ·kg−1, which, in turn, is used in a combined cycle to generate 19.58 MW of electrical power. The proposed economic assessment of the technology uses the energy generation processes as a reference, followed by a model for an overall economic evaluation. The results have shown that the profit could be up to USD 24.1 million, and the recovery of investment between 12 and 17 years would improve the environmental impac... [more]

In this paper, a flexible numerical framework to provide thermal performance assessment for the underground buried cables, considering different geological and meteorological conditions, has been presented. Underground cables tend to retain the heat produced in the conductor, so complex coupled thermo-hydraulic response of the porous medium surrounding the cables needs to be assessed to prevent cable overheating and the associated reduction in cable capacity for carrying current. Applying a coupled thermo-hydraulic model within the developed numerical framework to conduct a health assessment on a subset of National Grid Electricity Transmission’s underground cables, this study provides novel insights into the thermal behaviour of buried circuits. The results indicate that backfill and surrounding native soil have the dominant effect on the thermal behaviour of cables, while the amount of precipitation and ambient temperature were found to have less impact on cable’s thermal behaviour.... [more]

In this paper, a new design is provided so that the Z-source circuit breaker with a mechanical switch operates quickly at a low-impedance fault. When the fault occurs, the Z-source circuit breaker uses an impedance network to generate forced current zero crossing on the switch. This current zero-crossing time is not sufficient when mechanical switches are applied. In addition, since the MS switch operates through the fault detection sensor, the speed is slowed down. At a slower speed, the circuit breaker may not allow fault current isolation. To solve this problem, the Thomson coil was added to the circuit. It operates immediately in a low-impedance fault without additional fault detection devices. As a result, the faster operating speed is expected to reduce the size of the Z-source circuit breaker component and the stress of the breaker. It is mathematically analyzed and derived, and verified through simulations and experiments. The main features of the proposed model are fast detect... [more]

Nitrogen explosive decompression pretreatment was tested on barley straw, aspen wood, and pine wood in a two-step pretreatment approach. The two-step approach aims to avoid the uncontrolled degradation of hemicellulose during pretreatment and to recover high sugar yields from hemicellulose and cellulose. Additionally, the pretreated biomass was filtered after each pretreatment step with a fine metal sieve so that fermentation and hydrolysis inhibitors were removed. A total sugar yield of 43 g per 100 g of dry biomass was achieved from barley straw and aspen wood. For pine wood, the total sugar yield was significantly lower, with 12 g per 100 g of dry biomass. Possible reasons for this low sugar yield are the adsorption and deactivation of cellulases on softwood hemicellulose and on repolymerized lignin after pretreatment.

Water−gas displacement occurring during the drainage of water-soaked goafs facilitates the oxidation of water-soaked coal. The characteristics of oxygen migration and the oxidation and spontaneous combustion (SC) of soaked residual coal during goaf drainage were explored through laboratory research, water drainage simulation and on-site measurement. The results reveal that compared with raw coal samples, the amount and rate of gas products of water-soaked coal samples are higher in the heating oxidation process, demonstrating a strengthened spontaneous combustion (SC) propensity. Its cross-point temperature falls and the apparent activation energy decreases by 1.43−8.75%, that is, the soaked coal sample is easier to spontaneously combust during the drainage of water-soaked goafs. Through simulation, it is found that after water is drained, air leakage in the goaf is significantly intensified, and the pressure difference inside and outside the goaf reaches 498 Pa. By taking the air inle... [more]

Compared with the traditional cable, the high-temperature superconducting (HTS) cable has the advantages of low loss and large capacity transmission. At present, the research on HTS cables mainly focuses on the calculation of AC loss, the performance under specific working conditions and cooling system design. Relatively little research has been carried out on the basic design and overall layout optimization of the cables. In this paper, an HTS cable with a rated current of 4 kA was designed. Firstly, according to the selected superconducting cable parameters, the body design of cables with different structures was carried out and the corresponding finite element models were built. Then, the performance analysis of HTS cables with different layouts was carried out based on the proposed cable performance evaluation indicators and the CORC double-layer structure was determined as the scheme of this cable. Finally, the AC loss of the cable with this topology was calculated to be 9.81 J/m... [more]

The main objective of this research, directly related to the introduction of the COVID-19 pandemic, is to answer the question: has the epidemiological situation and energy crisis affected the CSR policy of transport industry companies and the forms of its implementation? This research aims to answer whether the social objective set out in the CRS policy, implemented by the studied entities, conflicts with commercial purposes, whether the implementation of CRS is profitable for these entities, and in which areas of activity it manifests itself. The aim is to investigate why the studied entities engage in CSR? The following research methods were applied: an economic and legal analysis of CRS principles and activity reports. The study focused on the activities of enterprises pursuing their business objectives and, at the same time, their socio-cultural mission. The CSR policies for 2019−2021, which surveyed transport industry companies operating in Poland, are analyzed. Empirical findings... [more]

The most common methods of reducing mercury emissions are the use of fixed bed granular sorbents and sorbent injection. However, both of these methods have disadvantages, such as increasing the flow resistance or the need to remove the sorbent from flue gas, respectively. These disadvantages can be eliminated by using sorbents permanently bound to construction materials (fixed sorbent materials—FSMs) or mixed with construction materials (sorbent polymer composites—SPCs). The approach is unique in the world literature as well as the development of three stands and procedures enabling the testing of FSMs or SPC materials based on Tarflen as a construction material. In order to further tests of FSMs and SPCs, the system for laboratory tests and two systems for industrial tests are developed. These stands and procedures enable determination of the influence of: FSM or SPC module shapes, flue gas properties (e.g., composition, temperature, flow rate), and mercury concentration on the effect... [more]

The application of expansion turbines at natural gas pressure reduction stations (PRS) is considered in order to recover energy contained in the natural gas. This energy is irretrievably lost at the reduction stations which use the traditional pressure reducer. Expanders allow for the electricity production for PRS own needs and for resale. The paper presents an analysis of the possibility of using turboexpanders at PRS in Poland. Authors performed static simulations for the assumed data sets and dynamic simulations for annual data from selected representative natural gas reduction and measurement stations. Energy balances are presented for the discussed scenarios that compare the energy requirements of natural gas pressure reduction stations which use a classic pressure reducer or turboexpander (TE). Using static simulations, authors investigated whether the use of a turboexpander is economically justified for the case if it is used only to supply the reduction station with electricit... [more]

The modest objective is to check the integrated effect of energy storage systems (ESSs) and distributed generations (DGs) and compare the optimization of the size and location of ESS and DG to explore its challenges for smart grids (SGs) modernization. The research enlisted different algorithms for cost-effectiveness, security, voltage control, and less power losses. From this perspective, optimization of the distribution network’s energy storage and capacity are being performed using a variety of methods, including the particle swarm, ant-lion optimization, genetic, and flower pollination algorithms. The experimental outcomes demonstrate the effectiveness of these techniques in lowering distribution network operating costs and controlling system load fluctuations. The efficiency and dependability of the distribution network (DN) are both maximized by these strategies.

Hydrogen energy storage (HES) systems have recently received attention due to their potential to support real-time power balancing in a power grid. This paper proposes a data-driven model predictive control (MPC) strategy for HES systems in coordination with distributed generators (DGs) in an islanded microgrid (MG). In the proposed strategy, a data-driven model of the HES system is developed to reflect interactive operations of an electrolyzer, hydrogen tank, and fuel cell, and hence the optimal power sharing with DGs is achieved to support real-time grid frequency regulation (FR). The MG-level controller cooperates with a device-level controller of the HES system that overrides the FR support based on the level of hydrogen. Small-signal analysis is used to evaluate the contribution of FR support. Simulation case studies are also carried out to verify the accuracy of the data-driven model and the proposed strategy is effective for improving the real-time MG frequency regulation compar... [more]

The Sun is a huge and clean energy source that must be relied upon to reduce greenhouse gases and promote the renewable and sustainable energy transition. In this paper, the testing of Al, Cu, and Fe metals with different thicknesses, both bare and painted matte black, was investigated for solar water heating systems. The used technique was a direct contact flat solar heating system (DCFSHS). Many experiments were run to assess this system in terms of metals’ thicknesses and their thermal conductivities as well. Thicknesses of around 0.35 mm and 1 mm of Cu gave almost similar feedback. Maximum temperatures in the range of 93−97 °C were achieved during the autumn season in Amman, Jordan, while it was approximately 80 °C in winter. It has been confirmed that high water temperatures can be obtained in all used metals, regardless of their thermal conductivities. It was also found that a white color of the solar heater case inner wall leads to an increase in water temperature of approximate... [more]

In response to global warming, China has formulated the “double carbon” strategic goals of peaking carbon dioxide emissions before 2030 and reaching carbon neutrality before 2060. The problem of rural carbon emissions is often ignored due to underdeveloped industries and services. In this paper, the carbon emission pathways in the rural areas of Guangdong Province are investigated. Since energy consumption is the main source of carbon emissions, the factor analysis was used to analyze the main factors affecting rural household energy consumption and agricultural production energy consumption. Multiple linear regression was conducted to predict the rural energy consumption demand in Guangdong. Furthermore, the current situation and development trend of rural energy supply, demand and consumption structure, and the potential of renewable energy development were considered to predict carbon emissions in the rural areas of Guangdong. Moreover, the carbon emission pathways in the rural area... [more]

Wireless sensor networks (WSNs) are considerably used for various environmental sensing applications. The architecture and internal specifications of WSNs have been chosen based on the requirements of particular applications. On this basis, WSNs consist of resource (energy and memory)-limited wireless sensor nodes. WSNs initiate data communication from source to destination via physical layer management principles, channel slot scheduling principles (time division multiple access), wireless medium access control (WMAC) protocols, wireless routing protocols and application protocols. In this environment, the development of WMAC principles, routing protocols and channel allotment schemes play crucial roles in network communication phases. Consequently, these layering functions consume more energy at each sensor node, which leads to minimal network lifetime. Even though the channel management schemes, medium control protocols and routing protocols are functionally suitable, the excessive... [more]

Single widespread employment of renewable energy sources (RESs) contributes to the shortage in the inertia of the microgrid (MG). After this, frequency stability may regress as a result of power imbalance or minor load fluctuations. This paper proposes an explicit adaptive modified virtual inertia control (VIC) based on an online Archimedes optimization algorithm (AOA) identifier for MG containing thermal, wind, and solar photovoltaic power plants. The Rung Kutta approach is used to construct the proposed online identifier, which acts as a model of the MG. AOA predicts the coefficients of the online identifier based on the input and output of MG to mimic the frequency deviation of the MG online. AOA estimates online the inertia and damping coefficients of the VIC system with an energy storage device based on online AOA identifier coefficients. The frequency deviation of the MG based on the proposed explicit adaptive modified VIC is compared with the conventional VIC based on fixed para... [more]

Renewable energies have an essential role in reducing various forms of pollution. The policymakers within the European Union place more and more emphasis on the replacement of internal combustion engine vehicles with electric vehicles in order to reduce emissions. The aim of this research is to analyze the current trends in producing and using renewable energy until 2028 and to estimate the impact of replacing the current internal combustion engine cars with electric cars. The significance of this study emerges from the estimation of the amount of electricity needed to replace current cars with electric cars and if it can be covered from green sources, based on the forecast of green energy until the year 2028. In addition, we also calculate in this study the impact on the public budgets of the European Union member states, as a result of the reduction of excise duties for fuels, following the reduction of their consumption. The research was carried out based on the extensive literature... [more]

Monitoring centers in the smart grid exchange the collected data by sensors and smart meters to monitor the current conditions and performance of electric power components. Distribution Power Transformers (DPTs) have a key role in maintaining the integrity of power flow in the smart grid. Online monitoring of DPTs to detect possible faults can potentially increase the reliability of modern power systems. Mechanical defects of DPTs are the major issues in their proper operation that must be detected in their early stage of occurrence. One of the most effective solutions for diagnosing mechanical defects in DPTs is Frequency Response Analysis (FRA). In this study, an appropriate condition monitoring scheme for DPTs is developed to identify even minor winding defects. Disk-Space Variation (DSV), a common DPT windings fault, is applied to the 20 kV-winding of a 1.6 MVA DPT in various locations and with different severity. Their corresponding frequency responses are then computed, and all f... [more]

CO2 emissions have been identified as the main driver for climate change, with devastating consequences for the global natural environment. The steel industry is responsible for ~7−11% of global CO2 emissions, due to high fossil-fuel and energy consumption. The onus is therefore on industry to remedy the environmental damage caused and to decarbonise production. This desk research report explores the Bio Steel Cycle (BiSC) and proposes a seven-step-strategy to overcome the emission challenges within the iron and steel industry. The true levels of combined CO2 emissions from the blast-furnace and basic-oxygen-furnace operation, at 4.61 t of CO2 emissions/t of steel produced, are calculated in detail. The BiSC includes CO2 capture, implementing renewable energy sources (solar, wind, green H2) and plantation for CO2 absorption and provision of biomass. The 7-step-implementation-strategy starts with replacing energy sources, develops over process improvement and installation of flue gas ca... [more]

Film cooling has dramatically contributed to the performance improvement of gas turbines, as it is a very effective cooling technique for gas turbines. Large eddy simulation (LES) began to be used in the study of film cooling 20 years ago, and meaningful results have been found, but it has not yet been intensively reviewed. In this review paper, we analyze and introduce about 70 papers published on LES of film cooling over the past 20 years. Numerical instability must be overcome, and realistic inflow must be generated to perform LES of film cooling. This review summarizes how the groups that performed LES of film cooling solved these problems. In film-cooling research, the main topics are improving the film-cooling performance by preventing the lift-off of the injectant and the effect of flow conditions on film cooling. In addition, LES has also been conducted extensively on the above two topics, and this review focuses on them. Finally, turbulence statistics of film-cooling flow obta... [more]

Chloride molten salts have become a potential heat storage material for the design of a new generation of concentrating solar power (CSP) (>700 °C) due to its abundant reserves and low cost. The difficulty of measuring the high-temperature thermal properties of chlorides can be effectively solved by using molecular dynamics simulation. However, it is challenging to get the thermophysical properties of multi-component molten salts containing CaCl2 due to the lack of Born−Mayer−Huggins (BMH) potential parameters of CaCl2. Through comparative analysis of the structure and thermal properties of CaCl2, including density and thermal conductivity, a set of Born−Mayer−Huggins (BMH) potential parameters of CaCl2 named SP2 is determined in this study. The density, specific heat capacity, and thermal conductivity of nine eutectic molten salts are simulated, including NaCl-CaCl2, KCl-CaCl2, NaCl-CaCl2-MgCl2, and NaCl-CaCl2-KCl, and the simulation results are found to be in good agreement with the... [more]

As part of the pre-conceptual design activities for the European DEMOnstration plant, a carefully selected set of safety analyses have been performed to assess plant integrated performance and the capability to achieve expected targets while keeping it in a safe operation domain. The DEMO divertor is the in-vessel component in charge of exhausting the major part of the plasma ions’ thermal power in a region far from the plasma core to control plasma pollution. The divertor system accomplishes this goal by means of assemblies of cassette and target plasma facing units modules, respectively cooled with two independentheat-transfer systems. A deterministic assessment of a divertor in-vessel Loss-of-Coolant Accident is here considered. Both Design Basis Accident case simulating the rupture of an in-vessel pipe for the divertor cassette cooling loop, and a Design Extension Conditions accident case considering the additional rupture of an independent divertor target cooling loop are assessed... [more]

We present a novel meshing and simulation approach for wind farms, featuring realignment and mesh adaptation. The turbines are modeled with actuator discs, which are discretized by means of an adaptation process to represent a level set function. The level-set-based simulation framework is combined with an adaptation cycle to capture both the solution and the actuator discs. In addition, we devise a turbine realignment process which takes into account the actual flow in the actuator disc configuration. Several results are presented to highlight the features of the approach. First, the adaptive simulation approach is validated, fulfilling the theoretical convergence rates and improving the accuracy of the boundary tight representations. Second, the adaptive simulation process is applied to a full wind farm configuration featuring 219 turbines, illustrating that is it well devised for complex wind farm configurations. Third, the turbine reorientation process is validated in a one turbine... [more]

The purpose of the paper is to analyse the relationship between digitalisation of public services (e-government) and ESG factors (environmental, social and economic factors). As public administration is a major stakeholder influencing sustainable development and state governments are aiming to digitise their services, there is a need to better understand the effect of the digital revolution on ESG. This article aims to study the relationship between the E-Government Development Index (EGDI) and ESG factors in 26 European countries. The linear ordering method TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) was used for the study, followed by the Perkal index and the method of optimal predictors’ selection—the Hellwig method. The study is based on the Eurostat data (in the period 2003−2020), and the analysis includes ten variables: Share of environmental taxes in GDP; Exposure to dust air pollution; Greenhouse gas emissions by source sector—carbon dioxide, methane... [more]