Kenichi Yamazaki, Hiroyuki Yasui, Tsuyoshi Noguchi
et al.
Atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PECVD) enables low-temperature coating in open air, yet the interplay between precursor activation and ambient-derived species remains unclear. Here, thin films from an amine precursor are deposited using a helium plasma and characterized by gas chromatography–mass spectrometry (GC-MS), a quartz crystal microbalance (QCM), and X-ray photoelectron spectroscopy (XPS). GC-MS indicates partial precursor conversion and formation of oxygen- and nitrogen-containing products, consistent with participation of ambient air and moisture. QCM identifies a limited precursor-concentration window in which mass increases monotonically during plasma exposure and remains constant after shutdown; outside this window, post-discharge mass loss occurs, indicating desorption of weakly bound species. XPS confirms carbon-rich films incorporating oxygen- and nitrogen-containing functionalities and complete substrate coverage at higher precursor concentrations.
Abstract Syntactic foam materials, due to their advantages of low densities, low water absorption, and high dielectric strengths, have significant application potential in the cores of post insulators. However, because of a large number of microbubble structures within the syntactic foam, it might decrease the partial discharge inception voltage. It is necessary to investigate the partial discharge characteristics of the foam to assess the feasibility of its internal insulation application. In this study, the syntactic foam samples with four different microsphere contents (0%–2%) were prepared, and the physical structures of the materials were characterised by using Fourier transform infrared spectroscopy, scanning electron microscopy, and three‐dimensional computed tomography. Subsequently, finite element simulations of the electric field were performed to analyse the influence of the microsphere content and distribution on the internal electric field of the syntactic foam. The results suggested that both the microsphere content and distribution affected the partial discharge activity. When the microsphere content was low, the doping of microspheres essentially meant that more air gap defects were present, leading to a decrease in the partial discharge performance. However, when the microsphere content was high, the microspheres were distributed in a dense and orderly manner, improving the field concentration phenomenon and hence inhibiting the partial discharge to a certain extent. In conclusion, the findings of this study provide a data reference and theoretical support for the application of syntactic foam in the cores of composite post insulators.
The successful implementation of Smart Grids heavily relies on energy efficiency, particularly through the Advanced Metering Infrastructure (AMI) and Smart Electricity Meters (SEM). However, cyber-attacks pose a threat to SEM, with electricity theft being a primary motivation. Despite the valuable data provided by SEM for analytical purposes, existing methods to identify theft involve cumbersome and costly on-site inspections. This research proposes an electricity theft detection model using the Long Short-Term Memory (LSTM) network. The model employs a collective anomaly approach, defining prediction errors through a threshold and forecast horizon. Suspicious consumption profiles are analysed, and a fuzzy inference system (FIS) implemented in MATLAB 2021b is used to model security risks based on these profiles. The study utilizes energy consumption data from four diverse consumer profiles (consumers 1, 2, 3, and 4) to develop consumer-specific LSTM models for detection and an FIS model for confirmation. Tampered consumer data is identified and confirmed based on selected AMI parameters. While all consumers exhibit suspicious profiles at times, only consumers 2 and 3 are confirmed as engaging in electricity theft. This research provides a robust approach to detecting and verifying fraudulent consumption profiles within the context of AMI, offering a more reliable dimension to theft detection and confirmation.
As part of a broad strategy to reach net-zero greenhouse gas emissions and limit global warming, many countries are requiring all new buildings to have net-zero energy use. This requires that on-site energy use not exceed on-site generation of renewable energy (taken here to be solar energy), or equivalently, that the building Energy Use Intensity (EUI, kWh/m2a) not exceed the supply of on-site solar energy (electricity and heat) per m2 of floor area per year. On this basis, we find that achieving net-zero energy performance in an archetype 40-story square building in 16 different cities of North America requires EUI of 17–24 kWh/m2a using PV panels, and 19–28 kWh/m2a using PVT collectors. Changing building orientation to a non-square floor shape can improve maximum permitted EUI by up to 50% in PV and 60% in PVT case. Conversely, the best-performing residential and commercial buildings have EUIs of 50–75 kWh/m2a. Only if building heights are limited to 5–10 floors does the available solar energy, and thus the permitted EUI, reach 50–75 kWh/m2a. Therefore, we recommend that policymakers not require high-rise buildings to be net-zero energy, unless they are prepared to limit building heights to 5–10 floors.
Environmental technology. Sanitary engineering, Building construction
Marco Antonio Islas-Herrera, David Sánchez-Luna, Jorge Miguel Jaimes-Ponce
et al.
Energy harvesting is a clean technique for obtaining electrical energy from environmental energy. Mechanical vibrations are an energy source that can be used to produce electricity using piezoelectric energy harvesters. Vibrations and wind in bridges have the potential to produce clean energy that can be employed to supply energy to electronic devices with low consumption. The purpose of this paper was to validate the functioning of an energy harvester and test the electrical power generation potential of a system based on the oscillation of a rod with a tip mass to stimulate piezoelectric transducers by impact. The obtained results showed the electric energy productions for different test conditions. Experimentally, the proposed structure produced 0.337 µJ of energy after 14 s of testing. In addition, after one hour of operation, an estimated production of 10.4 mJ was obtained, considering four stacks of 25 piezoelectric disks each when periodic impacts of 50 N at 5.7 Hz stimulated the transducers. In future work, we will focus on taking advantage of the vibrations produced in the proposed structure induced by the mechanical vibration of bridges and vortex-induced vibration (VIV) through interaction with wind to produce clean energy that is useful for low-power applications.
Negawatt trading is expected to improve energy efficiency via the prediction of peak demands and power-saving requests. However, the amount of power saved by consumers is not stable. The accurate prediction of demands and making appropriate requests with respect to power saving are difficult obstacles that need to be overcome in order to attain useful negawatt trading processes. To increase the accuracy of predictions and requests, earlier research suggests some methods or linear problems. On the other hand, the investigation of factors that affect consumption is important for correcting the current instability. In this research study, weather changes including temperature, time passing, and the consciousness of consumers are considered as important factors against electricity demands. In this paper, we propose a behavioral model of consumers using weather data. By using this behavioral model, the effectiveness of the suggested methods in earlier research for improving negawatt trading and the uncertainty of negawatts caused by weather changes is investigated.
The study was conducted to determine the carbon footprint of poultry farms. Breeder farms were included in the study. The fuel and electricity bills from farm, house size and age, flock size and number of flocks per year, and manure management were all collected. The methane, nitrous oxide, and carbon dioxide equivalent emissions were calculated, as well as the effect of these gases on breeder farms productivity, as well as determining the carbon footprint of breeder farms to reduce the negative effects of greenhouse gas emissions. In addition to providing necessary information on breeder’s chicken performance and advising poultry farmers on the relative merits of different climatic conditions to help set standards for different production traits. The experiments were conducted of closed farms in the city of Mansoura during the period from May 2019 to December 2021 and the capacity of the farm was 43,300 breeders’ chickens. The results showed that the amount of methane gas produced from the farm was 1.76 ton ch4 yr-1 and nitrous oxide gas was 0.13 ton n2o yr-1 for manure management. Thus, the total emissions of manure management are estimated at 81.65 tons of co2-eq. The amount of greenhouse gas emissions for diesel is 5.23 tons of co2-eq. The amount of greenhouse gas emissions (GHG) for the electricity used in the farm is 0.15 tons of co2-eq. In the end, the total amount of emissions produced from the farm is 87.04 tons of co2-eq. In the end, the total amount of carbon dioxide equivalent emissions generated from Egypt’s farms is 271.8 (kiloton co2-eq).
Extreme natural disasters and other events are likely to cause large-scale failures of the transmission networks. In order to minimize the economic losses and improve the post-disaster resilience of transmission networks, firstly, according to the connotation of transmission network resilience, the expected system load recovery efficiency is proposed as the resilience evaluation index; secondly, the post-disaster emergency maintenance process of transmission networks is analyzed, and a collaborative optimization model of time-uncertainty based post-disaster emergency maintenance strategy is established for transmission networks, which not only considers the resilience-improving economy of transmission networks, but also the constraints such as resources and path planning in the process of post-disaster maintenance. An improved particle swarm optimization (PSO) algorithm is proposed for the optimization model, which uses such methods as the multi-dimensional indefinite length coding, sub-group collaborative optimization, and Monte-Carlo-simulation-based fitness evaluation to improve the standard PSO algorithm. The simulation results of an IEEE RTS-79 case show that the improved particle swarm optimization algorithm can effectively solve the proposed optimization model, and the results of the collaborative optimization model can effectively improve the transmission network resilience index and the economy of post-disaster emergency maintenance.
Electricity, Production of electric energy or power. Powerplants. Central stations
Due to the insufficient understanding of the mechanism for soil strengthening by using Ionic Soil Stabilizer (ISS), the application of ISS in soil treatment is limited. In this paper, red clay samples were treated by using ISS and the effects were examined by the Atterberg test and uniaxial pressure test. In order to understand the mechanism, ISS dilution-based seepage test and ξ-potential test have been carried out. The results show that the ISS-Water mixture of 1 : 200 was the most effective ratio to reduce the plasticity index. The measurements indicate the thickness of the pair-electricity layer of adjacent clay layers and the repulsion force among soil particles is reduced, which in turn enhances the attraction force of the clay layers. This process strengthens the connection among the soil particles and thus increases the strength of the soil as detected by the experimental tests.
The world’s demand for electrical energy is increasing rapidly while the use of fossil fuels is getting limited more and more by energy policies and the need for reducing the impact of climate change. New sources of energy are required to fulfill the world’s demand for electricity and they are currently found in renewable sources of energy, especially in solar and wind power. Choosing the optimal PV nominal power minimizes the unnecessary surplus of electrical energy that is exported to the grid and thus is not making any impact on the grid more than necessary. Oversizing the PV system according to the Croatian net-metering model results in switching the calculation of the costs to the prosumer model which results in a decrease of the project’s net present value (NPV) and an increase in the payback period (PP). This paper focuses on formulating and solving the optimization problem for determining the optimal nominal power of a grid-connected PV system with a case study for Croatia using multiple scenarios in the variability of electricity production and consumption. In this paper, PV systems are simulated in the power range that corresponds to a typical annual high-tariff consumption in Croatian households. Choosing the optimal power of the PV system maximizes the investor’s NPV of the project as well as savings on the electricity costs. The PP is also minimized and is determined by the PV production, household consumption, discount rate, and geographic location. The optimization problem is classified as a quadratically constrained discrete optimization problem, where the value of the optimal PV power is not a continuous variable because the PV power changes with a step of one PV panel power. Modeling and simulations are implemented in Python using the Gurobi optimization solver.
Akbar Esmaeilzadeh, Diako Khademi, Reza Mikaeil
et al.
Selecting the propriate place of mineral processing plant is one of the most important steps in setting up it. It depends on several factors that make it a subroutine of multi criteria decision making (MCDM) problem. In this research, locating an optimal site for quarries processing plant, using VIKOR method is studied. Three sites were considered for this purpose and criteria such as transportation, water supply, electricity supply, gas supply, distance to markets, the price of land, topography and distance to where personal supplement place for the three possible regions were analyzed. After calculating parameters of VIKOR method, according to the obtained and ranked Q values of 0.8969, 0.0000, 0.1000, respectively for three possible cases of place A1, A2 and A3, case of A2 is selected as best choice.
In the current context of transition from the powertrains of cars equipped with internal combustion engines to powertrains based on electricity, there is a need to intensify studies and research related to the command-and-control systems of electric vehicles. One of the important systems in the construction of an electric vehicle is the thermal management system of the battery with the role of optimizing the operation of the battery in terms of performance and life. The article aims to critically analyze the studies and research conducted so far related to the type, design and operating principles of battery thermal management systems (BTMSs) used in the construction of various shaped Li-ion batteries, with focus on cooling technologies. The advantages and disadvantages of the individual components, as well as of the proposed BTM solutions, are extensively investigated, with regard also to the adaptability of these systems to the different Li-ion battery shapes. The information thus synthesized provides the necessary and important information and proposes future directions in research to those interested in this topic to be used to increase the efficiency of the thermal management systems of the battery (and with it the global efficiency of the electric vehicle).
In this research, we present a novel design for a large scale spectral splitting concentrator photovoltaic system based on double flat waveguides. The sunlight concentrator consists of a Fresnel lens array and double waveguides. Sunlight is firstly concentrated by Fresnel lenses then reaches an upper flat waveguide (UFW). The dichroic mirror-coated prisms are positioned at each focused area to divide the sunlight spectrum into two bands. The mid-energy (mid E) band is reflected at the prism surface and coupled to the UFW. The GaInP/GaAs dual-junction solar cell is attached at the exit port of the UFW to maximize the electrical conversion efficiency of the mid E band. The low-energy (low E) band is transmitted and reaches a bottom flat waveguide (BFW). The mirror coated prisms are utilized to redirect the mid E band sunlight for coupling with the BFW. The GaInAsP/GaInAs dual-junction solar cell is applied to convert the low E band to electricity. The system was modeled using the commercial optic simulation software LightTools™. The results show that the proposed system can achieve optical efficiencies of 84.02% and 80.01% for the mid E band and low E band, respectively, and a 46.1% electrical conversion efficiency for the total system. The simulation of the system performance and comparison with other PV systems prove that our proposed design is a new approach for a highly efficient photovoltaic system.
This paper focuses on the short-term cascade hydro scheduling problem, especially in a competitive environment, namely in market conditions. A nonlinear stochastic optimization method is proposed to take into consideration the hydroelectric energy production as a function of hourly electricity market prices and water release rates. In order to solve a case study based on one of the Turkish cascaded hydropower facilities, the proposed method has been successfully applied to a wide variety of problems at a negligible computation time while providing a higher profit. The paper shows the benefits that could be achieved by applying a model based on the Quasi-Newton Method, which finds zeroes or local maxima and minima of solving a certain type of optimization functions because it can better handle the uncertainty, constraints, and complexity of the problem. Ten-year hourly water inflow data and electricity market prices were used as inputs, and the results of the cascade and single optimization were compared. A comparison study with the operation of each hydropower plant (HPP) separately showed that 18 % higher income was obtained with a cascade variant.
Michał Kaczmarczyk, Barbara Tomaszewska, Leszek Pająk
The article presents an assessment of the potential for using low enthalpy geothermal resources for electricity generation on the basis of the Małopolskie Voivodeship (southern Poland). Identification the locations providing the best prospects with the highest efficiency and possible gross power output. Thermodynamic calculations of power plants were based on data from several geothermal wells: the Bańska PGP-1, Bańska IG-1, Bańska PGP-3 and Chochołów PIG-1 which are working wells located in one of the best geothermal reservoirs in Poland. As the temperature of geothermal waters from the wells does not exceed 86 °C, considerations include the use of binary technologies—the Organic Rankine Cycle (ORC) and Kalina Cycle. The potential gross capacity calculated for existing geothermal wells will not exceed 900 kW for ORC and 1.6 MW for Kalina Cycle. In the case of gross electricity, the total production will not exceed 3.3 GWh/year using the ORC, and will not exceed 6.3 GWh/year for the Kalina Cycle.
Marco Stecca, Laura Ramirez Elizondo, Thiago Batista Soeiro
et al.
Recent developments in the electricity sector encourage a high penetration of Renewable Energy Sources (RES). In addition, European policies are pushing for mass deployment of Electric Vehicles (EVs). Due to their non-controllable characteristics, these loads have brought new challenges in distribution networks, resulting in increased difficulty for Distribution System Operators (DSOs) to guarantee a safe and reliable operation of the grid. Battery Energy Storage Systems (BESSs) are promising solutions for mitigating the impact of the new loads and RES. In this paper, different aspects of the BESS's integration in distribution grids are reviewed. At first, the physical layer will be considered, focusing on the main battery technologies commercially available and on the power electronics converter. Secondly, the different functionalities that a grid-connected BESS can provide will be investigated, and then its sizing, location and control in distribution network will be discussed. In addition, an overview of actual BESSs installations is given. All in all, this paper aims at providing a comprehensive view of BESSs integration in distribution grids, highlighting the main focus, challenges, and research gaps for each one of these aspects.
The level of price elasticity for electricity service has always been a subject rife with controversy. Estimates of price elasticity in this industry have varied widely, and little if any consensus exists on what the true level of price elasticity is. This lack of consensus is evident in regulatory filings involving electricity rate increases, where price elasticity is generally ignored as a factor influencing future sales and revenues after the rate increases occur. Complicating the issue further is the question of exactly what price (if any) electricity customers are responding to: the total bill, the marginal (per kWh) rate, or some combination thereof. And of course, the answer to this question will be affected by the existence of any customer‐facing programs that make consumers more aware of and/or provide incentives to respond to time‐varying electricity prices.
In charging process of electric vehicle, a misalignment between the transmitter (Tx) and receiver (Rx) coupling structure decreases the efficiency of the wireless power transfer. In inductive power transfer system, misalignment reduces the effective coupling between the Tx and Rx coils. In this work, based on previous multiple coil structures, a new multi coil design in proposed to increase the efficiency of the power transfer. Here, a multi coil structure with two rectangular and four spiral coils is designed with the overall dimension of the coil structure 26.5 cm x 36.5 cm. The measurement shows, that for coil distance below 10.3 cm and a lateral misalignment of maximal 10 cm (27.4%), the efficiency of the designed multi coil structure is better compared to previous coil structures. However for larger coil distance or larger misalignment, the efficiency of the new coil structure deteriorates significantly.
The current state of the economy and society is influenced by the global integration processes taking place in Eurasia - the creation of the Eurasian Economic Union, which should unite the markets for resources, goods and capital of the member states of the Eurasian Economic Union. One of the aspects of this process is the creation of a unified electricity market, which ensures free flow of electrical energy, free pricing and competition in the power industry. The purpose of this study is to study the degree of readiness of national energy systems for integration and to identify problems that impede the formation of the Common Electricity Market of the Eurasian Economic Union. The methods used were statistical analysis tools, a graphical method, comparisons and descriptions. The study was carried out on the basis of the use of information provided in the open access of the Eurasian Economic Union, national statistical services and energy companies. The authors have identified the main goals and objectives, as well as the requirements and expected results of the creation of the Common Electricity Market. As a result of the analysis of national power systems, a number of problems were identified that impede their convergence, including inconsistencies in the scale of production, various pricing mechanisms and electricity price regulation, differences in the energy balance of the Eurasian Economic Union member states, different levels of electricity prices, and a particular opinion Of the Republic of Belarus to the concept of market formation and the lack of unified borders of Armenia with other participating countries Union. The findings of the study indicate that by the stated date, namely July 1, 2019, the Common Electricity Market will most likely not be created for the reasons stated. To solve the identified problems, the authors propose several tools, one of the most important among them is the mechanism of regulatory and legal regulation of electricity markets at the national and supranational levels. Also, according to the authors, in the integration processes in the framework of the Eurasian Economic Union should consider the world experience of such political and economic associations.