Trends in Renewable Energy
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WITHDRAWN: Exergy and Energy Analysis of a CHP System with a Gas Turbine and a Horizontal Axis Wind Turbine
Get PDFThis article has been withdrawn at the request of the author. The Publisher apologizes for any inconvenience this may cause.Citation: Norouzi, N. (2021). WITHDRAWN:Â Exergy and Energy Analysis of a CHP System with a Gas Turbine and a Horizontal Axis Wind Turbine. Trends in Renewable Energy, DOI: 10.17737/tre.2021.7.1.00130
Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules
Get PDFSolar photovoltaic (PV) modules consist of solar cells connected in series to provide the required output power. The solar PV system is experiencing major challenges, which are mainly due to the partial shadows on the photovoltaic modules leading to mismatching power loss and hot spot problems. Hotspots have become a major cause of PV module failure. The Cell Partition Technique (CPT) is proposed to reduce hotspots and minimize mismatch losses caused by partial shadings. Specifically, each solar PV cell (Full cell) in a solar PV module is divided or partitioned into two half cells (known as Half-Cut Cells or HC) and three equal cells (known as Tri-Cut Cells or TC) in accordance with the proposed technique. The HC and TC types of cells are connected in a strings of series-parallel connection, and bypass diode is placed in middle of the solar PV module to ensure proper operation. The primary aim of this research is to model, evaluate, and investigate the performance of solar PV arrays using new PV modules are developed based on Cell Partition Technique (PVM-CPT), such as half-cut cell modules (HCM), and tri-cut cell modules (TCM) and compared with full-sized cell modules (FCM). These PVM-CPT are connected in Series–Parallel (SP), Total-Cross-Tied (TCT), and proposed static shade dispersion based TCT reconfiguration (SD-TCTR) for the array sizes of 3x4, 4x3 and 4x4, respectively. The purpose is to select the most appropriate solar PV array configurations in terms of the highest global maximum power and thus the lowest mismatch power losses under short and narrow, short and wide, long and narrow, long and wide type of cell level partial shadings. The Matlab/Simulink software is used to simulate and analyze all of the shading cases. The results show that, when compared to conventional module configurations under different shading conditions, the proposed static SD-TCTR arrangement with TC modules (SDTCTR-TCM) exhibits the lowest mismatch power losses and the greatest improvement in array power. Corrigendum to "Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules" is published on 01/12/2022. Citation: BALARAJU, V., and Chengaiah, C. (2022). Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules. Trends in Renewable Energy, 8, 1-26. DOI: 10.17737/tre.2022.8.1.0013
Exergy and Energy Analysis of Wind-Thermal System
Get PDFCurrent wind systems are intermittent and cannot be used as the baseload energy source. The research on the concept of wind power using direct thermal energy conversion and thermal energy storage, called wind powered Thermal Energy System (WTES), opened the door to a new energy system called Wind-thermal, which is a strategy for developing baseload wind power systems. The thermal energy is generated from the rotating energy directly at the top of the tower by the heat generator, which is a simple and light electric brake. The rest of the system is the same as the tower type concentrated solar power (CSP). This paper’s results suggest that the energy and exergy performance of the WTES (62.5% and 29.8%) is comparable to that of conventional wind power, which must be supported by the backup thermal plants and grid enhancement. This cogeneration nature of the WTES system makes this system suitable for using wind power as a direct heat source in several heat-demanding processes such as chemical production. Also, the light heat generator reduces some issues of wind power, such as noise and vibration, which are two main bottlenecks of the wind power technology.Citation: Norouzi, N. (2021). Exergy and Energy Analysis of Wind-Thermal System. Trends in Renewable Energy, 7(1), 73-86. DOI: 10.17737/tre.2021.7.1.0013
Enhance the Output Power of a Shaded Solar Photovoltaic Arrays with Shade Dispersion based TCT Configuration
Get PDFPartial shading has a negative impact on the performance parameters of a Solar Photovoltaic (PV) array, because it shades certain panels while leaving others un-shaded. This article focuses on modeling, comparing and performance assessment of 6×6, 6×5 and 5×6 size shadowed solar PV arrays under different partial shading cases in the MATLAB/ Simulink software. For this purpose, the simulation of series-parallel (SP), Total-Cross-Tied (TCT) and proposed shade dispersion based TCT (SD-TCT) type of array configurations was carried out under few shading cases. The proposed SD-TCT was designed using the shades dispersion technique, which is based on a number logic approach. In this technique, in order to effectively remove the row-current mismatches in the TCT PV array configuration, the shaded and un-shaded modules in an array were re-arranged, so that the shading on modules expands across the whole array. The physical placement of the TCT array modules has been reordered in accordance with the proposed number logic pattern exclusive of altering the electrical links among the panels. The simulation results showed that the performance of the SD-TCT type was superior to that of conventional array configurations.Citation: Bala Raju, V., and Chengaiah, C. (2021). Enhance the Output Power of a Shaded Solar Photovoltaic Arrays with Shade Dispersion based TCT Configuration. Trends in Renewable Energy, 7, 1-23. DOI: 10.17737/tre.2021.7.1.0012
Pyrolysis-Gas Chromatography/Mass Spectrometry Analysis of Oils from Different Sources
Get PDFRegenerated gutter oil (i.e., waste oil) accounts for 10% of the edible oil market, which has caused serious food safety issues. Currently, there is no standard protocol for the identification of the gutter oil. In this study, the pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) method was employed to analyze eleven oil samples including edible vegetable oils (tea oil, corn oil, olive oil, sunflower oil, peanut oil and blend vegetable oil) and waste oils (used frying oil, lard, chicken fat, inferior oil and kitchen waste grease). Three factors of pyrolysis temperature, reaction time and sample volume were investigated to optimize the analytical parameters. The optimal pyrolysis conditions were determined to be 600°C, 1 min and an injection volume of 0.3 μL. Five characteristic components (tetradecane, z,z-9,12-octadecadienoic acid, decanoic acid-2-propenyl ester, 17-octadecenoic acid, and z-9-octadecenoic acid) were found in all oil samples. The existence of C11-C16 olefins in the pyrolytic products of the animal fats and the other low-quality oils could be utilized to distinguish vegetable oils from gutter oils.Â
Information Technology, Artificial Intelligence and Machine Learning in Smart Grid – Performance Comparison between Topology Identification Methodology and Neural Network Identification Methodology for the Branch Number Approximation of Overhead Low-Voltage Broadband over Power Lines Network Topologies
Get PDFBroadband over Power Lines (BPL) networks that are deployed across the smart grid can benefit from the usage of machine learning, as smarter grid diagnostics are collected and analyzed. In this paper, the neural network identification methodology of Overhead Low-Voltage (OV LV) BPL networks that aims at identifying the number of branches for a given OV LV BPL topology channel attenuation behavior is proposed, which is simply denoted as NNIM-BNI. In order to identify the branch number of an OV LV BPL topology through its channel attenuation behavior, NNIM-BNI exploits the Deterministic Hybrid Model (DHM), which has been extensively tested in OV LV BPL networks for their channel attenuation determination, and the OV LV BPL topology database of Topology Identification Methodology (TIM). The results of NNIM-BNI towards the branch number identification of OV LV BPL topologies are compared against the ones of a newly proposed TIM-based methodology, denoted as TIM-BNI.Citation: Lazaropoulos, A. (2021). Information Technology, Artificial Intelligence and Machine Learning in Smart Grid – Performance Comparison between Topology Identification Methodology and Neural Network Identification Methodology for the Branch Number Approximation of Overhead Low-Voltage Broadband over Power Lines Network Topologies. Trends in Renewable Energy, 7(1), 87-113. doi:http://dx.doi.org/10.17737/tre.2021.7.1.0013
Management Information Systems and Data Science in the Smart Grid - Inner Class Area Capacity Distribution of the iSHM Class Maps of Overhead Low-Voltage Broadband over Power Lines Topologies
Get PDFOn the basis of the initial Statistical Hybrid Model (iSHM), the iSHM class maps, which are 2D contour plots and may graphically classify the real and virtual OV LV BPL topologies into five class areas, are upgraded in this paper by exploiting the third dimension of the capacity so that the upgraded class maps can provide additional information concerning the inner class area capacity distribution. The comprehension of the behavior of the inner class area capacity distribution is critical in order to deeper understand the extent and the position of iSHM class map footprints when various operation conditions of OV LV BPL topologies occur. Two inner class area capacity distribution rule of thumbs that deal with the OV LV BPL topology classification and capacity estimation are proposed thus supporting the management information system of OV LV BPL networks.Citation: Lazaropoulos, A. (2020). Management Information Systems and Data Science in the Smart Grid - Inner Class Area Capacity Distribution of the iSHM Class Maps of Overhead Low-Voltage Broadband over Power Lines Topologies. Trends in Renewable Energy, 6(3), 245-265. doi:http://dx.doi.org/10.17737/tre.2020.6.3.00122
Statistical Channel Modeling of Overhead Low Voltage Broadband over Power Lines (OV LV BPL) Networks - Part 2: The Numerical Results of Class Map Footprints of Real OV LV BPL Topologies, Branch Line Faults and Hook Style Energy Thefts
Get PDFIn [1], the theoretical framework for the interoperability of DHM, iSHM, mSHM, the definition procedure and the class maps has been first presented for OV LV BPL networks. But the main interest of the first paper has focused on the theory of the OV LV BPL topology footprints of TIM, FIIM and HS-DET method on the class maps.In this paper, the numerical results concerning the application of iSHM, mSHM, the definition procedure and the class maps to OV LV BPL networks are first shown. Then, given the iSHM and mSHM class maps, the footprints of TIM, FIIM and HS-DET method databases for the OV LV BPL topologies are highlighted. Finally, a technique for the detection of branch line faults and hook style energy thefts that is based on iSHM and mSHM footprints is proposed.Citation: Lazaropoulos, A. (2020). Statistical Channel Modeling of Overhead Low Voltage Broadband over Power Lines (OV LV BPL) Networks - Part 2: The Numerical Results of Class Map Footprints of Real OV LV BPL Topologies, Branch Line Faults and Hook Style Energy Thefts. Trends in Renewable Energy, 6(1), 88-109. doi:http://dx.doi.org/10.17737/tre.2020.6.1.0011
Technical Overview of the Net Metering in Lebanon
Get PDFIn order to realize the best practices to allow the individuals participate in renewable energy production, a collection of legislation was ratified, and a set of decisions was introduced to encourage the prosumer concept. This notion, which is called Net Metering (NEM), is a billing mechanism that credits PV solar system owners for the energy injected to the grid. Lebanon adopts the NEM policy to reduce the demand and boost the grid through increasing the generation capacity. The decline of solar equipment cost encourages people to subscribe to the NEM service by utilizing the PV solar systems. The implementation of the NEM service provides the customers with leverage over their electricity bills. However, connecting the home micro grid into the vast grid is not easy. It imposes many technical challenges which are discussed in this article
Global Solar Radiation Characteristics at Calabar and Port Harcourt Cities in Nigeria
Get PDFThis study analyzed the inter-annual variability in solar radiation at Port Harcourt and Calabar, aiming at improving knowledge of solar resources. For the investigation, monthly mean global solar radiation data for fifteen years (2000 - 2014) was collected from Nigerian Meteorological Agency (NIMET), and the monthly mean extraterrestrial solar radiation was determined using globally recognized standard relation. The clearness index parameter was employed for characterizing the spatial variability of solar radiation for Calabar and Port Harcourt. The statistics of the monthly mean solar radiation deviations of Port Harcourt and Calabar was tested using the Kolmogorov-Smirnov method. The test results showed that they are normally distributed random variables. Furthermore, the analysis of sequential properties showed that the coefficients of the auto-correlation with lag 1 are significant for both stations. The auto-correlation coefficients with lag 1, though usually not significant, are negative for both stations. The auto regression lag 1 (AR-1) is the recommended procedure (model equation) for generating monthly solar radiation synthetic time series, with auto-correlation coefficients varying from 0.30 to 0.47 for both stations in the South-South of Nigeria.Citation: Amadi, S., Dike, T., & Nwokolo, S. (2020). Global Solar Radiation Characteristics at Calabar and Port Harcourt Cities in Nigeria. Trends in Renewable Energy, 6(2), 111-130. doi:http://dx.doi.org/10.17737/tre.2020.6.2.0011