Electric Power Usage Research Articles

The Quest for Renewable Energy—Effects of Different Asphalt Mixes and Laboratory Loading on Piezoelectric Energy Harvesters

In furtherance of the quest for green renewable and sustainable energy, an effort was made in this laboratory study to generate and harvest electric power from hot-mix asphalt (HMA); a viscoelastic material that is widely used for road construction. The underlying hypothesis is that the mechanical vibrations and strain energy induced by vehicle loading on the road (pavement) can be harnessed and converted into usable electric power by embedding piezoelectric sensors within the HMA layers of the pavement structure. To investigate the effects of HMA mix type on the generated energy, four commonly used Texas mix types, namely Type B (coarse-graded), Type C (dense-graded), Type D (dense-to-fine graded), and Type F (fine-graded), with up to seven different HMA mix-design volumetric characteristics were comparatively evaluated in the laboratory. In the study, the effects of loading, namely load magnitude and loading frequency, were investigated by simulating the traffic loading in the laboratory through comparative testing with the Hamburg wheel-tracking tester (HWTT) and the universal testing machine (UTM), respectively, at different temperature conditions. A prototype highway sensing and energy conversion (HiSEC) module with piezoelectric sensors was utilized for converting the applied stress on the HMA into harvestable electric energy during HWTT and UTM laboratory testing, respectively. The generated electric current, voltage, and power were measured and quantified using a multipurpose power meter. Overall, the study demonstrated that there is promising potential to harvest energy from HMA when subjected to transient loading under different temperature conditions. However, further refinement of the HiSEC module and piezoelectric sensors is still warranted to optimize the power generation and harvesting capacity, both in terms of efficiency and power output.

Transfer learning for multi-objective non-intrusive load monitoring in smart building

Buildings represent 39% of global greenhouse gas emissions, thus reducing carbon emissions in buildings is of importance to greenhouse gas emissions reductions. This requires understanding how electricity is utilized in the buildings, then optimizing electricity management to seek conservation of energy. Non-intrusive load monitoring (NILM) is a technique that disaggregates a house’s total load to estimate each appliance’s electric power usage. Several strategies for estimating one appliance at a time (one-to-one model) have been presented and experimentally proven to be effective, with two mainstream trends: appliance transfer learning and cross-domain transfer learning. The former refers to the transfer between different types of appliances in the same data domain, while the latter refers to the transfer between different data domains for the same type of appliance. Different from the previous work, this paper explores the approach of adopting one model for all appliances (one-to-many model) and proposes a novel transfer learning scheme, that incorporates appliance transfer learning and cross-domain transfer learning. Thus, a well-trained model can be transferred and utilized to effectively estimate the power consumption in another data set for all appliances, which demands fewer measurements and only one model. Three public data sets, REFIT, REDD, and UK-DALE, are used in our experiments. Further, a set of smart electricity meters was deployed in a practical non-residential building to validate the proposed method. The results demonstrate the accuracy and practicality compared to start-of-the-art one-to-one NILM transferred models.

ENERGY HARVESTING – NEW GREEN ENERGY

Energy Harvesting is the process in which energy is captured from a system's environment and converted into usable electric power. Energy harvesting allows electronics to operate where there's no conventional power source, eliminating the need to run wires or make frequent visits to replace batteries, that makes it the new possibility of green energy source. This short letter reports the 3 new designed energy harvesting systems based on the electromagnetic and piezoelectric effect from two universities, i.e. Lublin University of Technology (Poland) and University College Dublin (Republic of Ireland). The proposed systems can be used as a power supply for low-energy devices or in the diagnostics.

Methods of Pre-Clustering and Generating Time Series Images for Detecting Anomalies in Electric Power Usage Data

As electricity supply expands, it is essential for providers to predict and analyze consumer electricity patterns to plan effective electricity supply policies. In general, electricity consumption data take the form of time series data, and to analyze the data, it is first necessary to check if there is no data contamination. For this, the process of verifying that there are no abnormalities in the data is essential. Especially for power data, anomalies are often recorded over multiple time units rather than a single point. In addition, due to various external factors, each set of power consumption data does not have consistent data features, so the importance of pre-clustering is highlighted. In this paper, we propose a method using a CNN model using pre-clustering-based time series images to detect anomalies in time series power usage data. For pre-clustering, the performances were compared using k-means, k-shapes clustering, and SOM algorithms. After pre-clustering, a method using the ARIMA model, a statistical technique for anomaly detection, and a CNN-based model by converting time series data into images compared the methods used. As a result, the pre-clustered data produced higher accuracy anomaly detection results than the non-clustered data, and the CNN-based binary classification model using time series images had higher accuracy than the ARIMA model.

A review of conventional and new-generation aircraft starter/generators in perspective of electric drive applications

PurposeMore electric aircraft (MEA) is defined as the extensive usage of electric power in aircraft. The demand for electric power in new generation aircraft rises due to environmental and economic considerations. Hence, efficient and reliable starter/generators (SGs) are trending nowadays. The conventional main engine starting system and power generation system can be replaced with an individual SG. The constraints of the SG should be investigated to handle the aviation requirements. Even though the SG is basically an electric machine, it requires a multidisciplinary study consisting of electromagnetic, thermal and mechanical works to cope with aviation demands. This study aims to review conventional and new-generation aircraft SGs from the perspective of electric drive applications.Design/methodology/approachFirst of all, the importance of the MEA concept has been briefly explained. Also, the historical development and the need for higher electrical power in aircraft have been indicated quantitatively. Considering aviation requirements, the candidate electrical machines for aircraft SG have been determined by the method of scoring. Those machines are compared over 14 criteria, and the most predominant of them are specified as efficiency, power density, rotor thermal tolerance, high-speed capability and machine complexity. The features of the most suitable electrical machine are pointed out with data gathered from empirical studies. Finally, the trending technologies related to efficient SG design have been explained with numeric datasets.FindingsThe induction motor, switched reluctance motor and permanent magnet synchronous motor (PMSM) are selected as the candidate machines for SGs. It has been seen that the PMSM is the most preferable machine type due to its efficient operation in a wide range of constant power and speed. It is computationally proven that the using amorphous magnetic alloys in SG cores increases the machine efficiency more. Also, the benefits of high voltage direct current (HVDC) use in aircraft have been explained by a comparison of different aircraft power generation standards. It is concluded that the HVDC use in aircraft decreases total cable weight and increases aircraft operation efficiency. The thermal and mechanical tolerance of the SG is also vital. It has been stated that the liquid cooling techniques are suitable for SGs.Originality/valueThe demand for electrical power in new generation aircraft is increasing. The SG can be used effectively and efficiently instead of conventional systems. To define requirements, constraints and suggestions, this study investigates the SGs from the perspective of electric drive applications.

Off-planet power supply

One of the most pressing questions facing the world today is that of how to ensure a reliable source of energy that comes without carbon emissions or the 'intermittency' associated with existing sources of renewables. According to Martin Soltau it is a question with an answer that is clearly visible every day - the Sun. But Soltau, currently business manager for aerospace with engineering consultancy Frazer-Nash, is not arguing for increasing areas of the Earth's surface to be covered in solar panels. Instead he is a proponent of a much more radical idea. This is that massive satellites that could ultimately measure several kilometres across be put into orbit to convert sunlight into electricity in a highly efficient manner free from atmospheric interference and then beam it down to Earth in the form of microwave radiation for conversion back into usable electric power.

Solar Power Generation in Smart Cities Using an Integrated Machine Learning and Statistical Analysis Methods

Presently, photovoltaic systems are an essential part of the development of renewable energy. Due to the inherent dependence of solar energy production on climate variations, forecasting power production using weather data has a number of financial advantages, including dependable proactive power trading and operation planning. Megacity electricity generation is regarded as a current research problem in the modern features of urban administration, particularly in developing nations such as Iran. Machine learning could be used to identify renewable resources like transformational participation (TP) and photovoltaic (PV) technology; based on resident motivational strategies, the smart city concept offers a revolutionary suggestion for supplying power in a metropolitan region. The sustainable development agenda is introduced at the same time as this approach. Therefore, the article’s goals are to estimate Mashhad, Iran’s electrical power needs using machine learning technologies and to make innovative suggestions for motivating people to generate renewable energy based on the expertise of experts. The potential of solar power over the course of a year is then assessed in our research study in Mashhad, Iran, using the solar photovoltaic modelling tool. The present idea in this research uses linear regression techniques to forecast utilising artificial neural networks (ANN). The most important factor in sizing the installation of solar power producing units is the daily mean sun irradiation. The amount of power that will be produced by solar panels can be estimated using the mean sun irradiance at a particular spot. A precise prediction can also be used to determine the complexity of the system, return on investment (ROI), and system load metrics. Several regression techniques and solar irradiance-related metrics have been combined to forecast the mean sun irradiation in terms of kilowatt hours per square metre. Azimuth and zenith factors considerably enhance the performance of the model, as demonstrated by the proposed method. The results of this study demonstrate 99.9% reliability rate for ANN model prediction of the electrical power usage during the summer and winter seasons. Thus, the maximum of power requirement during the hottest and coolest periods can be managed by using the photovoltaic system’s renewable power projections.

Numerical investigation of hydrodynamic performance of flapping foils for energy harvesting

Micro-power generators are increasingly becoming popular to meet the power requirements of micro-electromechanical systems, such as small sensors. One such resource of harnessing energy is through exploiting flow instabilities found in vortex-induced vibrations, flutter, etc. In this work, we numerically investigate the hydrodynamic performance of fully forced flapping foils with the goal to exploit their underlying physical mechanisms for the development of micro-power generators. We consider prescribed combination of plunging and pitching motions imposed to a NACA-0012 airfoil. We conduct a parametric study by varying the Strouhal number and the amplitude of the pitching angle to identify two operational flow regimes: power generation and thrust-producing propulsion using the feathering criterion. In the latter regime, the foil performs positive work on the surrounding fluid and therefore, the positive propulsive efficiency can be attained as long as the horizontal hydrodynamic force remains negative. For the power generation regime, the product of the lift force and plunging velocity is found mostly positive over the oscillating cycle, which indicates that the flowing fluid carries out work on the foil. The parametric study reveals that the foil can reach up to 42% power generation efficiency when setting the pitching amplitude in the range of 60° to 70°. For foils operating in the power generation regime, we present a piezoelectric energy harvester that can efficiently harness usable electric power from high fluid pressure regions. We identify two core locations based on the pressure field at which the attachment of piezoelectric patches can lead to significant energy harvesting. As such, the present study provides guidance for the design enhancement of micro-power generators relying on the interactions of flapping foils with the surrounding fluid.

The Impacts of Electrolyte Composition on Key Performance Metrics of the All-Aqueous Copper Thermally Regenerative Ammonia Battery

A significant amount of the potential energy that is generated during energy harvesting worldwide is discarded as waste heat because of inefficient power generation cycles. Much of this wasted power source goes unused because it is trapped as low-grade thermal energy (< 100 °C), which traditional power cycles cannot viably harness. With the advent of electrochemical power systems such as redox flow batteries and fuel cells, researchers are investigating new methods of providing usable electric power from these unused low-grade thermal energy sources. The thermally regenerative ammonia battery (TRAB) is one promising technology in this space, as it operates with the same principles as a flow battery except that TRABs can be recharged using low-grade waste heat instead of electric power. Of the TRAB chemistries proposed, the all-aqueous copper TRAB chemistry is capable of both large power densities and energy densities, and high coulombic efficiencies. In this presentation, we discuss how key performance metrics relevant to power generation from low grade thermal energy sources are strongly influenced by electrolyte composition and battery operating parameters. Manipulating the ammonia to copper ratio demonstrated clear tradeoffs between achievable energy and power capacities. Increasing ligand concentration had a large impact on electroactive species solubility and cell potential differences, which increased the theoretical energy density limit of the battery. Increasing the amount of ammonia relative to dissolved copper raised peak power density, but adversely affected energy density. Moderate increases in discharge current density did not decrease the energy density due to reduced impact of ammonia crossover which appears to be a dominant source of energy loss in TRABs.

Power setting based on load using phase control on conveyor system

The advantage of using conveyors that have been successfully designed through this research is in the power settings based on the load’s condition on the conveyor in which we hope that the system performance would be better in terms of electrical power usage. The conveyor’s speed control system used the PWM (Pulse Width Modulation) method, a pulse width setting to supply current for the engine. Inputs come from a Load cell censor that measures the weight together with the motor’s activator. Microcontroller ATMega328 is used as a controller of the system. When the system is activated, the controller will activate the motor activator with the PWM signal based on the load weight The Microcontroller then identifies the load weight and determines the PWM count to set the corresponding power and speed. Through the optocoupler, Microcontroller provides the pulse to control the gate on the TRIAC (Triode for Alternation Current), which acts as a phase controller connected to the induction motor to power the conveyor. The result of this research shows that the heavier the load is, the generated power will correspondingly be higher.

An empirical assessment of electricity consumption and environmental degradation in the presence of economic complexities

To a large extent, the theories and concepts behind the effect of ecological footprint have been the paramount concern of the recent literature. Since the rising and falling of environmental degradation have been a continuous issue since the first phase of development, determinants such as economic complexity may play a critical role in achieving long-term sustainable development in the framework of environmental Kuznets curve (EKC) paradigm. Therefore, this research expands on the notion of an EKC paradigm for the world’s top ten most complex economies by considering four variables, such as real GDP per capita, electricity consumption, trade openness, and a new putative factor of environmental obstacle, the economic complexity index (ECI). This is one of the first studies to look at the impact of ECI on the ecological footprint of a specific sample from 1998 to 2017. The findings demonstrate a continuous inverted U-shaped link between real GDP per capita, the square of real GDP per capita, and ecological footprint. The EKC hypothesis is found to be valid in the long term in the examined complex economies. The findings of the panel autoregressive distributed lag (ARDL) of the pooled mean group (PMG) and fully modified ordinary least squares (FMOLS) estimations demonstrate that in the long term, electric power usage contributed to the carbon footprints. Furthermore, the economic complexity index and trade openness increase environmental performance over time. To determine if there is causation between the variables, we employ the panel vector error correction model (VECM) framework. Particularly, the results show unidirectional causality running from electric power consumption to ecological footprint and bidirectional causal relationship between (1) economic growth and ecological footprint; (2) square of economic growth and ecological footprint; (3) economic complexity index and ecological footprint; and (4) trade openness and ecological footprint.

Research on customer’s electricity consumption behavior pattern

The fine-grained customer load data provides a large amount of information for the analysis of customer’s electricity consumption behavior pattern. Therefore, this paper proposes an algorithm for identifying the electricity consumption patterns of electric power users based on k-means algorithm. Our method is verified on the electricity consumption data of Irish residents and Shanghai Southern Industrial and Commercial users. The experimental results show that our method can divide the curves with similar electricity consumption patterns efficiently.

Increment of Fault Current due to integration of Distributed Generation and its impact on Distribution Network protection

One of the new technologies in generating power near the distribution system is called distributed generation which has supportive and destructive characteristics to the power system protection. One of the destructive characteristics of distributed generation is increasing the level of fault current to the protective equipment of the power system that affects the existing time intermission coordination of the protective overcurrent relay. In addition to increment of fault, it also alters the radial nature of the power distribution system and cause the power bidirectional rather than unidirectional. Integration of distributed generation to the distribution network causes increment of fault current effect, reliability drop, and affects security of protection system. The level of failure of protection be contingent on type, size, location and number of distributed generation. This fault current can cause a great damage to the electrical equipment with the miss operations of protective devices. The main aim of this paper is analysis of the fault current level to the protection of distribution network due to the integration of distributed generation which concerns on solar distributed generation, wind distributed generation and combination of solar and wind distributed generations at a time. This paper conducts the increment of fault current by the integration of distributed generation to the distribution system and its impact on distribution network protection. The analysis and the modeling are conducted on the 15KV distribution network of the radial feeder in Debre Markos town. This paper has covered the ling to ground, line to line and three phase fault analysis and their impact on the protection of distribution system for the wind and solar distributed generation types. After the integration of the distributed generation the fault current is increased by 0.529KA for three phase, 0.74KA for line to ground, 0.467KA for line to line and 0.523KA for line to line to ground. This paper confirms designing distribution network without forecasting the future demand of electric power users give the protection equipment additional requirement. As the result, the fault current after the integration of distributed generation to the distribution network have great value in terms of power system protection.

Green Building Concept Application with VRF Air Conditioning System

The objective of this research is to find out the benefit of the Green Building Concept application with VRF Air Conditioning System at Indonesian Computer University. The research method used is descriptive quantitative analysis. Based on research findings, the VRF air conditioning system in Indonesian Computer University could reduce electrical power usage and the monthly cost for electrical power. However, the payback can only be reached after 15 years of operation. The other benefits are the space efficiency for more flexible placement of the outdoor unit and did not decrease the building's aesthetic appearance.

A Study on the Application of Solar Panel Technology in Low-Income Residential Housing in Deli Serdang Regency

The need for energy use, especially electrical energy continues to increase from year to year. One of the sectors that consume the largest electrical energy is the household sector which consumes about 27% of the total energy consumption of all sectors. The main energy source in Indonesia at this time still comes from fossil energy, although the government has tried to develop various renewable energy sources for the future. Solar energy is one of the renewable energies that is quite potential for Indonesia considering the level of solar radiation in Indonesia is quite high throughout the year. The selection of subsidized housing as the object of research is due to the existence of clear regulations and the number which also continues to increase every year. Through the collection of physical data on the research location, such as analysis of shadows, roof structure, solar irradiation data, average electric power usage, the average solar energy requirement of the subsidized housing will be obtained. Furthermore, by calculating the economic value, it will be obtained how the description of the possibility of applying solar energy to subsidized housing will be obtained. If possible, the application of solar energy in subsidized housing can help government programs to use renewable energy and reduce the use of fossil energy

Design and Build Wireless Relay with Electricity Monitoring Based on Internet of Things

Electricity is a power source to run various electronic devices. Problem that often occurs is that users forget to turn off or turn on their electronic devices, then prepaid and postpaid electricity users cannot monitoring the electrical power usage of their electronic devices in realtime. The designed device to overcome these problems has a working principle like a switch, but there has relays and several sensors. Controlling electronic devices can be done by user using main switch in designed device, switch button and timer feature in Android application, then user can also monitoring the voltage, current and power in realtime on Android application. The results of several tests that have been done show that the designed device and Android applications that have been built can run well, but the current reading generated by the designed device are still not perfect, adjustments are needed so power calculation is better.&#x0D; Keywords : Android, Control, Electricity, IoT, Monitor

Design and Research of Power Information Acquisition System for Smart Grid

In order to realize the of all electric power users “full coverage, full acquisition”, this article in view of the situation of electric power information collection launches the research, in the same power load management system at home and abroad, substation meter reading system, residents centralized meter reading system such as electric field data acquisition system on the basis of comparative analysis, combining with the characteristics of the power of the county area. A new information acquisition system for power users is designed. By adopting the technology of layered design and multi-channel access, the concrete solution ideas and methods of supporting multi-terminal, multi-protocol, multi-channel and multi-application services are put forward. Results show that the system of collection scope covers the existing centralized meter reading system, distribution transformer monitoring system and load management system, the system conforms to the national modernization development direction and the requirement of electric power marketing information, to be advanced and practical, compared with the similar systems in a dominant position, have achieved satisfactory results in practical operation, the application prospect is very broad.

Short Survey of Architectures of Photovoltaic Arrays for Solar Power Generation Systems

Since the industrial revolution, the world’s economy has mainly relied on the consumption of fossil fuels. The burning of coal releases vast amounts of toxic COx greenhouse gasses into the atmosphere that bear an undesirable environmental impact. The ongoing offshore oil exploration activities; the infrastructure for oil extraction, production, and transportation; and the inevitable oil spills cause severe damage to the environment and huge loss of sea life, flora, and fauna. Recent awareness of the environmental issues and the worldwide climate change spurred public interest in clean and environmentally friendly “green” energy generation. Solar energy is an abundant and inexhaustible resource that can meet much of the worlds’ energy needs and, thus, has been in the focus of scientific attention for many years. Yet, converting solar energy into usable electric power is a formidable engineering and economical challenge. The recent environmental awareness triggered governments and private companies around the world to encourage further research and capital investment into the development and deployment of efficient and cost-effective solar technologies. This review reports on advances in the technological approaches that can be employed to convert sunlight to electricity. This article presents a short survey of the state-of-the-art architectures of photovoltaic arrays and a review of the concepts and strategies of their associated electronic power processors for solar energy generation. The paper aims to be of assistance to engineers and scientists who are already engaged or just joining this fascinating field, to promote the knowledge of photovoltaic energy and facilitate the proliferation of the solar power generation systems.

Power Generation from an Elastic Leidenfrost Hydrogel Piston Enabled Heat Engine

Leidenfrost phenomenon has been observed since 1756. Diverse Leidenfrost phenomenon based heat engines were developed for converting the thermal energy into mechanical form. Limited to the weak force, the Leidenfrost heat engines are rarely reported with usable electric power output. Here we propose an elastic Leidenfrost heat engine based power generator for the demonstration of thermal-to-electric power conversion. A saturated sodium polyacrylate super absorbing polymer sphere is employed as hydrogel piston for harvesting thermal energy to trigger elastic deformation and mechanical bouncing. A lightweight contact separation mode triboelectric nanogenerator (TENG) plays a role for the conversion from the tiny mechanical input into usable electric power. The dynamics of the hydrogel piston on hot plates, force generation during bouncing and electric power output are measured experimentally. The effects of piston stroke, working temperature, and water absorption rate of the hydrogel piston are discussed. A maximum open-circuit voltage of 22 V and peak power of 280 μW was obtained by a single 2-gram hydrogel piston and the output electric power from the hydrogel piston based power generator successfully lights up 22 commercial LEDs.

Performance study of a new smart hybrid parabolic trough collector system integrated with hybrid tubular thermoelectric generator

Advanced parabolic trough systems are the promising technologies for the production of usable heat and electrical power. Here we study the effects of hot water temperature adjustment concept and optical concentrator on the thermal and electrical efficiencies of a new PTC/HTTEG configuration, which comprises parabolic trough concentrator and hybrid tubular thermoelectric generator. The hybrid tubular thermoelectric generator (HTTEG) was integrated within the collector tube, where the hot water is passed between the inner side of the absorber tube and the top surface of the HTTEG. Meanwhile, to create a large temperature difference across the HTTEG sides, a cold water is passed along the inner side of the HTTEG. A low consumption pump was energized using HTTEG power in order to keep the hot water temperature at 95 °C for a long time (temperature adjustment concept). Numerical simulations show that the improvement in performance of the hybrid system highly depends on the adjustment concept and optical concentrator. As the solar concentration ratio increases, the overall efficiency of the hybrid system increases significantly to 76.21% and the amount of hot water reaches to a maximum value of about 846.77 Liter/Day for a concentration of 30 suns. Also, the power generated by the HTTEG and hot water temperature stay stable at 71.37 W and 95 °C, respectively, due to the hot water temperature adjustment effect. To validate the results of numerical model, a new validation method was proposed and discussed. The comparison of results obtained with results of the exact solution indicates a good agreement.