Electrical Energy Research Articles

Pengaplikasian Panel Surya dan Automatic Transfer Switch (ATS) untuk Menggerakkan Pompa Tanaman Hidroponik sebagai Sumber Energi Terbarukan

Solar panels are renewable energy which is very useful for agricultural needs to meet electricity needs, one of which is its application in agriculture, namely as a pump driver for hydroponic plants. Hydroponics is farming with an emphasis on meeting the nutritional needs of plants using water as a medium with a nutrient solution as fertilizer. In the hydroponic system the pump must be on continuously, for this reason the Automatic Transfer Switch (ATS) tool is used to substitute the electrical energy of the State Electricity Company (PLN) with the electrical energy of solar panels in the event of a power outage from the State Electricity Company (PLN) which aims to drain nutrient water. This research aims to apply solar panels to a hydroponic plant system and apply the Automatic Transfer Switch (ATS) tool as a substitute for the State Electric Company's (PLN) electrical energy and solar panels. This research was carried out on Jalan Polonia no.11 fresh water east, North Padang District, Padang City, West Sumatra in January – March 2024, with the initial stages (1) preparation, (2) solar panel assembly, (3) analysis of test results , (4) preparation of reports. The results of this research can determine the power output required by solar panels as a renewable energy source as well as the application of the Automatic Transfer Switch (ATS) in hydroponic plant cultivation.

CuO nanoflowers: Multifaceted implications of various precipitating agents on rectification behaviour

In order to achieve the best possible use of traditional energy resources for the preservation of the environment, semiconductor-based optoelectronic devices are one of the most intriguing methods for converting light energy into electrical energy. CuO has been extensively explored as a material for energy conversion and the development of photo-detectors due to its notable characteristics among other metals, especially its non-toxicity, abundance, high efficiency, electrochemical stability and low cost/promising photodiode. However, some drawbacks limit its practical application in white light and photo-detector, including the rapid recombination rate of photo-generated electron-hole pairs and destitute response to visible light. As a result, several strategies have been developed from an optoelectronics perspective to eradicate these deficiencies and make an effort to enhance CuO photodiode activities. In this research work, the electrical characteristics and rectification behaviour of CuO with various precipitating agents have been examined. The CuO nanoparticles can be synthesized by co-precipitation technique prepared with different precipitants. Through this research, several parameters, such as the structural, functional, morphological, optical and electrical characteristics, were investigated by changing the precipitants. The functional group formation of pure CuO phase was confirmed by FT-IR studies. UV–Vis absorption measurements indicate that the band gap of the CuO nanoparticles was ranging from 2.40 to 2.85 eV. As a diode, CuO/p-Si exhibits a non-ideal behaviour and under light conditions with Na2CO3 precipitant, the better ideality factor is about 2.35. The barrier height is determined by the thermionic emission theory to be 0.77 and 0.79 eV in the dark and light conditions respectively.

Energy poverty in light of the climate emergency in Sub‐Saharan Africa: Impact and transmission channels

AbstractThis study analyzes the effect of energy poverty on environmental quality for a sample of 43 countries in sub‐Saharan Africa. We specify and estimate a linear panel data model for the period 2000–2021, using fixed effects and the Driscoll‐Kraay method. The results show that access to electricity and clean energy for cooking have a positive and significant effect on deforestation and carbon emissions. Taking into account non‐linear analysis, we find that there is an inverted U‐relationship between energy indicators and environmental quality, thus, verifying the hypothesis of the Kuznet environmental curve. Thus, access to electricity and access to clean cooking energy improve environmental quality from a threshold. For the resolution of endogeneity, Lewbel 2SLS, the Kiviet method and S‐GMM were used. In addition, analysis of the sample data using a structural equation model (PLS‐SEM) shows that energy indicators pass through various channels to affect environmental quality. Therefore, based on these results, we recommend increasing investments in electricity infrastructure, especially in clean decentralized energy, in order to reduce deforestation and, therefore, CO2 emissions.

Encapsulation structure and in-situ embedding test and model study of a new type of road piezoelectric energy collector

In recent years, research on road piezoelectric energy harvesters (RPEH) has made great progress in the field of road vibration energy harvesting. However, the research on the packaging structure and embedding method of RPEH is not comprehensive. In this paper, a new type of transducer unit structure is developed, which can improve the electrical energy output compared with the drum piezoelectric transducer, and its waterproof performance of the transducer unit is tested under different water depth and duration. Then, a new RPEH package structure is made, and the output performance is compared with the three commonly used package structures in the current research, and the field construction of RPEH with different embedding methods is carried out on the actual road to evaluate the electrical energy output capacity of RPEH under different embedding methods, and the best construction method of RPEH is summarized through durability test. Finally, the three-dimensional simulation model of RPEH with different construction methods is established, and the stress and voltage are analyzed by finite element method to verify the best embedding method. The test results show that the piezoelectric output efficiency of the new transducer unit is increased by 38.9 %, and it still has good electrical energy output after 24 h immersion at a depth of 1.5 m, and its waterproof level reaches IPX8. Under larger excitation frequency and load, the indoor output of RPEH in the new package structure has better output performance in indoor test. The bolt-spring package is used to apply pre-pressure to RPEH, and the output efficiency of RPEH is improved. When the excitation conditions are 10 kN, 10 Hz, the output power is increased by 11.1 %, 127.3 % and 247.4 % compared with the other three package structures. The maximum power of RPEH is 3.41 W by placing concrete on the bottom surface of RPEH sponge washer and using asphalt as the pavement layer to ensure the durability of piezoelectric pavement. The finite element analysis illustrates the strain and voltage variation of piezoelectric pavement with different embedment modes, and the simulation results are consistent with the test results. The research results provide an important basis for the design of RPEH packaging structure and embedding method in road piezoelectric engineering.

Sustainable CO2 Refrigeration System for Fish Cold Storage Facility Using a Renewable Integrated System with Solar, Wind and Tidal Energy for Cape Verde—Analyzing Scenarios

This study compares four feasible alternative solutions for an integrated cold storage system in the city of Tarrafal, Santiago, Cape Verde. Integrated systems using grid electricity are compared with autonomous systems generating electrical energy from renewable sources, alongside various types of refrigeration facility systems. Its objective is to assess the energy efficiency, financial feasibility, and environmental impact across four scenarios. Scenario 1 utilizes two R134a refrigeration units powered by the public grid. Scenario 2 employs a transcritical R744 (CO2) system using grid electricity. Scenario 3 incorporates R744 and autonomous renewable energy. Scenario 4 employs R744 for refrigeration with seawater heat exchange and autonomous renewable energy sources. The findings favor Scenario 4, emitting 15,882 kg CO2 eq with a 5-year return on investment. Autonomous electricity production in this scenario reduces emissions by 95%. Despite an initial cost of EUR 769,172.00, Scenario 3 demonstrates financial viability, contributing to energy sustainability. This autonomous production reduces emissions by 360,697 kg CO2 compared to conventional systems, highlighting the positive impact of local renewable energy integration.

The Storage Process of Electric Energy Produced from Renewable Sources from Hydrogen to Domestic Hot Water Heating

The expansion of renewable electricity storage technologies, including green hydrogen storage, is spurred by the need to address the high costs associated with hydrogen storage and the imperative to increase storage capacity. The initial section of the paper examines the intricacies of storing electricity generated from renewable sources, particularly during peak periods, through green hydrogen. Two primary challenges arise: firstly, the complexity inherent in the storage technology and its adaptation for electricity reproduction; and secondly, the cost implications throughout the technological chain, resulting in a significant increase in the price of the reproduced energy. Electric energy storage emerges as a pivotal solution to accommodate the growing proportion of renewable energy within contemporary energy systems, which were previously characterized by high stability. During the transition to renewable-based energy systems, optimizing energy storage technology to manage power fluctuations is crucial, considering both initial capital investment and ongoing operational expenses. The economic analysis primarily focuses on scenarios where electricity generated from renewable sources is integrated into existing power grids. The subsequent part of this paper explores the possibility of localizing excess electricity storage within a specific system, illustrated by domestic hot water.

Analysis of reducing thermal resistance between the PCM and ambient air for improving the power generation characteristics of PCM-based thermoelectric power generators

A power generator comprising a thermoelectric device (TED) and a phase change material (PCM) allows energy harvesting from ambient temperature variations, which exist ubiquitously; thus, such a device has received considerable attention as an energy harvester that can operate at any location. We developed a model for estimating the characteristics of a power generator in ambient air, whose temperature is forcibly changed between two temperature values, such as when an air conditioner is turned on and off. We calculated the influence of latent heat and thermal conductivity of the PCM on the characteristics of power generators with various thermal resistances between the TED/PCM interface and ambient air. Latent heat and thermal conductivity of the PCM affect the amount of heat energy (Q) transfer between the ambient air and PCM and the energy conversion efficiency (ηE), respectively, where the amount of electric energy is given by Q × ηE. The increase in Q caused by an increase in the latent heat of the PCM was almost independent of the thermal resistance between the TED/PCM interface and air. However, the increase in ηE caused by an increase in the thermal conductivity of the PCM decreased as the thermal resistance between the TED/PCM interface and air increased. These results indicate that the techniques to improve the power generation characteristics by increasing the thermal conductivity of PCM, which have been frequently investigated in recent years, are effective only when the thermal resistance between the TED/PCM interface and ambient air is small.

Features and subjects of the contract for the supply of electricity to the consumer

In this study, the author examines in detail one of the types of sales contract - the energy supply contract, which in the late 20th - early 21st centuries is a necessary element of the life of society, a mandatory condition for the development of the economy, since the supply of energy resources to one degree or another requires all physical and entities. Over the past ten years, Ukrainian civil legislation, which regulates contractual relations, in particular relations in the field of energy supply, has radically changed. In the Civil Code of Ukraine, a whole group of articles regulating relations related to the conclusion, execution and termination of contracts in the field of energy supply appeared. The legal norms governing the relationship between electricity suppliers and its consumers have undergone radical changes. The relationship between the owner of energy and the organizations that transport it (electricity and heat networks) is being built in a fundamentally new way. Today, the question of whether energy is a thing and whether it can be the object of property rights is problematic and debatable. To what type is the contract according to which the power plant (as a supplier) undertakes to provide the consumer with electric energy? Can such an activity be considered contractual, since the power plant undertakes to carry out the work, the necessary delivery of energy to the consumer, or is it still another activity? In the article, the author considered the rules for concluding an energy supply contract and the features of a universal service provider. Particular attention is paid to the supplier of the «Last Event», the powers and duties of such an entity are disclosed. The author concludes that the contract for the supply of electric energy to the consumer can be considered both as a public contract and as a connection contract. The basic requirements for the electricity supplier from the consumer, the legality of its activity, the possibility of switching to a new supplier are indicated. Special features of the energy supply contract include: provision of energy through the connected network; availability of consumer energy metering devices; the right of the counterparty (energy supply organization) under the energy supply contract to supervise the technical condition of the consumer’s current receivers in order to ensure safety and reliable energy supply.

Life Cycle Economic and Environmental Assessment of Producing Synthetic Jet Fuel Using CO2/Biomass Feedstocks.

The aviation industry is responsible for over 2% of global CO2 emissions. Synthetic jet fuels generated from biogenic feedstocks could help reduce life cycle greenhouse gas (GHG) emissions compared to petroleum-based fuels. This study assesses three processes for producing synthetic jet fuel via the synthesis of methanol using water and atmospheric CO2 or biomass. A life cycle assessment and cost analysis are conducted to determine GHG emissions, energy demand, land occupation, water depletion, and the cost of producing synthetic jet fuel in Switzerland. The results reveal that the pathway that directly hydrogenates CO2 to methanol exhibits the largest reductions in terms of GHG emission (almost 50%) compared to conventional jet fuel and the lowest production cost (7.86 EUR kgJF-1); however, its production cost is currently around 7 times higher than the petroleum-based counterpart. Electrical energy was found to be crucial in capturing CO2 and converting water into hydrogen, with the sourcing and processing of the feedstocks contributing to 79% of the electric energy demand. Furthermore, significant variations in synthetic jet fuel cost and GHG emissions were shown when the electricity source varies, such as utilizing grid electricity pertaining to different countries with distinct electricity mixes. Thus, upscaling synthetic jet fuels requires energy-efficient supply chains, sufficient feedstock, large amounts of additional (very) low-carbon energy capacity, suitable climate policy, and comprehensive environmental analyses.

A Reliability and Risk Assessment of Solar Photovoltaic Panels Using a Failure Mode and Effects Analysis Approach: A Case Study

Solar photovoltaic (PV) systems are becoming increasingly popular because they offer a sustainable and cost-effective solution for generating electricity. PV panels are the most critical components of PV systems as they convert solar energy into electric energy. Therefore, analyzing their reliability, risk, safety, and degradation is crucial to ensuring continuous electricity generation based on its intended capacity. This paper develops a failure mode and effects analysis (FMEA) methodology to assess the reliability of and risk associated with polycrystalline PV panels. Generalized severity, occurrence, and detection rating criteria are developed that can be used to analyze various solar PV systems as they are or with few modifications. The analysis is based on various data sources, including field failures, literature reviews, testing, and expert evaluations. Generalized severity, occurrence, and detection rating tables are developed and applied to solar panels to estimate the risk priority number (RPN) and the overall risk value. The results show that the encapsulant, junction box, and failures due to external events are the most critical components from both the RPN and risk perspectives. Delamination and soiling are the panels’ most critical FMs, with RPN values of 224 and 140, respectively, contributing 16.2% to the total RPN. Further, moderately critical FMs are also identified which contribute 56.3% to the RPN. The encapsulant is the most critical component, with RPN and risk values of 940 (40.30%) and 145 (23.40%), respectively. This work crucially contributes to sustainable energy practices by enhancing the reliability of solar PV systems, thus reducing potential operational inefficiencies. Additionally, recommendations are provided to enhance system reliability and minimize the likelihood and severity of consequences.

FORMATION OF BIOENEGRY BY FOOD WASTE

Food that has been tossed out. Nearly three-fourths of the waste generated by inhabitants of the maximum city in the past year comprised food, according to an environment status report (ESR) released by the BMC for 2019-20. According to BMC & VVMC officials, the average waste generated per person per day is 250-650 grams. Waste management experts say if Mumbai recycles this waste, it could reduce the amount of garbage transported to its overburdened landfill. Food waste is an untapped energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. It’s better if we could somehow turn all the waste into clean energy and some other recyclable product. Food waste can be turned into valuable resources such as natural fertilizer, energy, and animal feed. Proper disposal of food waste has posed an environmental concern. also there is electric energy also can be made and the size of the dumping ground can be reduced. Also, we are going to make the all food waste management process digitalized so that Consumers can track the process of food waste management through the mobile application. The mobile application will help both consumers and as well as the government to maintain a record of their waste management, and it will be easy to take the record of the process, results, or how it can get improved. As we know the future generation will be mostly dependent upon renewable energy, so this type of food waste management process can save more energy for the future and will make a more human and animal-friendly nature/environment. So we can provide a good future for the next generations.

On the potential of vehicle-to-grid and second-life batteries to provide energy and material security

The global energy transition relies increasingly on lithium-ion batteries for electric transportation and renewable energy integration. Given the highly concentrated supply chain of battery materials, importing regions have a strategic imperative to reduce their reliance on battery material imports through, e.g., battery recycling or reuse. We investigate the potential of vehicle-to-grid and second-life batteries to reduce resource use by displacing new stationary batteries dedicated to grid storage. Based on dynamic material flow analysis, we show that equipping around 50% of electric vehicles with vehicle-to-grid or reusing 40% of electric vehicle batteries for second life each have the potential to fully cover the European Union’s need for stationary storage by 2040. This could reduce total primary material demand from 2020–2050 by up to 7.5% and 1.5%, respectively, which could ease geopolitical risks and increase the European Union’s energy and material security. Any surplus capacity could be used as a strategic reserve to increase resilience in the face of emergencies such as blackouts or adverse geo-political events.

Importance of the electrophoresis and pulse energy for siRNA-mediated gene silencing by electroporation in differentiated primary human myotubes

BackgroundElectrotransfection is based on application of high-voltage pulses that transiently increase membrane permeability, which enables delivery of DNA and RNA in vitro and in vivo. Its advantage in applications such as gene therapy and vaccination is that it does not use viral vectors. Skeletal muscles are among the most commonly used target tissues. While siRNA delivery into undifferentiated myoblasts is very efficient, electrotransfection of siRNA into differentiated myotubes presents a challenge. Our aim was to develop efficient protocol for electroporation-based siRNA delivery in cultured primary human myotubes and to identify crucial mechanisms and parameters that would enable faster optimization of electrotransfection in various cell lines.ResultsWe established optimal electroporation parameters for efficient siRNA delivery in cultured myotubes and achieved efficient knock-down of HIF-1α while preserving cells viability. The results show that electropermeabilization is a crucial step for siRNA electrotransfection in myotubes. Decrease in viability was observed for higher electric energy of the pulses, conversely lower pulse energy enabled higher electrotransfection silencing yield. Experimental data together with the theoretical analysis demonstrate that siRNA electrotransfer is a complex process where electropermeabilization, electrophoresis, siRNA translocation, and viability are all functions of pulsing parameters. However, despite this complexity, we demonstrated that pulse parameters for efficient delivery of small molecule such as PI, can be used as a starting point for optimization of electroporation parameters for siRNA delivery into cells in vitro if viability is preserved.ConclusionsThe optimized experimental protocol provides the basis for application of electrotransfer for silencing of various target genes in cultured human myotubes and more broadly for electrotransfection of various primary cell and cell lines. Together with the theoretical analysis our data offer new insights into mechanisms that underlie electroporation-based delivery of short RNA molecules, which can aid to faster optimisation of the pulse parameters in vitro and in vivo.

Environmental impact assessment of biohydrogen production from orange peel waste by lab-scale dark and photofermentation processes

Orange peel waste (OPW), as a relevant and recoverable residue, is composed of peel, internal tissue, pulp, and seeds. This organic residue is rich in carbohydrates useful for biofuel production processes. Biohydrogen is obtained from dark fermentation (DF) and photofermentation (PF), which are complementary in the bioprocessing chain. The objective of this work was to compare the environmental impact assessment of a sequential dark–photofermentation process (Scenario DF-PF) and the individual fermentation processes: dark fermentation (Scenario DF) and photofermentation (Scenario PF). The assessment was performed at a laboratory scale, and the functional unit (FU) was defined as the production of 1 kg H2. Scenario DF showed the lowest environmental impacts regarding global warming and fossil resource scarcity indicators, with 375.5 kg CO2-eq/FU and 108.8 kg oil-eq/FU, respectively, followed by Scenario DF-PF and Scenario PF. Scenario DF-PF presented the lowest impact regarding the water consumption indicator (7.6 m3/FU), followed by Scenario DF, which had 46.6% more impact. Additionally, Scenario DF-PF required 3.3 times less substrate than Scenario DF due to more efficient substrate conversion. The high share of fossil fuels in the Mexican electricity mix directly impacts the processes that require electric energy, such as the PF process. Therefore, eco-friendly light sources should be used to minimize effects. Valorization of OPW could follow two routes depending on whether the aim is to reduce a specific environmental impact indicator or biowaste conversion efficiency.

Investigation of hybrid power-to-hydrogen/natural gas and hydrogen-to-X system in Cameroon

In Sub-Saharan Africa (SSA), the capacity to generate energy faces significant hurdles. Despite efforts to integrate renewable energy sources and natural gas power plants into the energy portfolio, the desired reduction in environmental impact and alleviation of energy poverty remain elusive. Hence, exploring a spectrum of hybrid technologies, encompassing storage and hydrogen-based solutions, is imperative to optimize energy production while mitigating harmful emissions. To exemplify this necessity, the 216 MW Kribi gas power plant in Cameroon is the case study. The primary aim is to investigate cutting-edge emissions and energy schemes within the SSA. This paper assessed the minimum complaint load technique and four power-to-fuel options from technical, financial, and environmental perspectives to assess the viability of a natural gas fuel system powered with hydrogen in a hybrid mode. The system generates hydrogen by using water electrolysis, with photovoltaic electricity and gas power plant. This research also assesses process efficiency, storage capacity, annual costs, carbon avoided costs, and production prices for various fuels. Results showed that the LCOE from a photovoltaic solar plant is 0.19$/kWh, with the Power-to-Hydrogen process (76.2% efficiency) being the most efficient, followed by the ammonia and urea processes. The study gives a detailed examination of the hybrid hydrogen natural gas fuel system. According to the annual cost breakdown, the primary costs are associated with the acquisition of electrical energy and electrolyser CAPEX and OPEX, which account for 95% of total costs. Urea is the cheapest mass fuel. However, it costs more in terms of energy. Hydrogen is the most cost-effective source of energy. In terms of energy storage and energy density by volume, the methane resulted as the most suitable solution, while the ammonia resulted as the best H2 storage medium in terms of kg of H2 per m3 of storage (108 kgH2/m3). By substituting the fuel system with 15% H2, the environmental effects are reduced by 1622 tons per year, while carbon capture technology gathered 16,664 tons of CO2 for methanation and urea operations, yielding a total carbon averted cost of 21 $/ton.

Thermodynamic modeling and performance analysis of photovoltaic-thermal collectors integrated with phase change materials: Comprehensive energy and exergy analysis

Phase change materials (PCMs) integrated with photovoltaic-thermal (PVT) collectors can simultaneously generate and store electrical and thermal energy. However, design optimization requires accurate modeling of the complex heat transfer processes in PCMs under varying operating conditions. This study introduces an efficient simulation approach with generalized Nusselt number correlations to enable precise and rapid analysis of PCM thermal performance. A numerical model is developed to quantify heat fluxes, node temperatures, energy and exergy outputs across PCM solid, melting, and liquid states. Extensive analysis is conducted to explore the impact of irradiation, ambient temperature, PCM thickness, tilt angle, and wind speed on PVT performance. Key findings include: (1) thermal energy yield exceeds electrical output by 2.8 times owing to PV's low efficiency, while electrical exergy dominates thermal exergy by 5.3 times highlighting electric output's primacy; (2) electrical output chiefly depends on irradiation, while thermal energy and exergy are highly sensitive to ambient temperature and wind speed; (3) thermal energy escalates 4.5 times faster than electrical energy with irradiation rise, but thermal exergy drops sharply from 10.1 to 0.34 W as ambient temperature increases from 0 to 35 °C due to quality factor degradation. The study provides new generalized correlations, validated model, and extensive performance assessment to advance PCM-based PVT collector design.

Towards a Sustainable Laser Powder Bed Fusion Process via the Characterisation of Additively Manufactured Nitinol Parts

Is additive manufacturing (AM) a sustainable process? Can the process be optimised to produce sustainable AM parts and production techniques? Additive manufacturing offers the production of parts made of different types of materials in addition to the complex geometry that is difficult or impossible to produce by using the traditional subtractive methods. This study is focused on the optimisation of laser powder bed fusion (L-PBF), one of the most common technologies used in additive manufacturing and 3D printing. This research was carried out by modulating the build layer thickness of the deposited metal powder and the input volumetric energy density. The aim of the proposed strategy is to save the build time by maximizing the applied layer thickness of nitinol powder while retrieving the different AM part properties. The saving in the process time has a direct effect on the total cost of the produced part as a result of several components like electric energy, inert gas consumption, and labour. Nickel-rich nitinol (52.39 Ni at.%) was selected for investigation in this study due to its extremely high superplastic and shape memory properties in addition to the wide application in various industries like aerospace, biomedical, and automotive. The results obtained show that significant energy and material consumption can be found by producing near full dens AM parts with limited or no alteration in chemical and mechanical properties.

Literature Review on Conjugated Polymers as Light-Sensitive Materials for Photovoltaic and Light-Emitting Devices in Photonic Biomaterial Applications

Due to their extended p-orbital delocalization, conjugated polymers absorb light in the range of visible–NIR frequencies. We attempt to exploit this property to create materials that compete with inorganic semiconductors in photovoltaic and light-emitting materials. Beyond competing for applications in photonic devices, organic conjugated compounds, polymers, and small molecules have also been extended to biomedical applications like phototherapy and biodetection. Recent research on conjugated polymers has focused on bioapplications based on the absorbed light energy conversions in electric impulses, chemical energy, heat, and light emission. In this review, we describe the working principles of those photonic devices that have been applied and researched in the field of biomaterials.

Validation of satellite-derived solar irradiance datasets: a case study in Saudi Arabia

A robust dataset of Surface Solar Irradiance is essential for secure competitive financing for solar energy projects. Rating agencies and lenders alike require verification of the solar-resource dataset for utilizing each solar energy project, as this can be translated directly into expected electrical energy and revenues. The accuracy of the dataset and the variability of solar radiation, as recorded by historical solar data, play a significant role in estimating the future performance of the project and its budget. The historical observed solar irradiance datasets by local stations are the best and most reliable for a specific site, but they are not always available for long and continuous periods in any location, especially in arid areas. So, the importance of historical solar radiation datasets derived from satellite-based models arises here. This paper validates the historical modeled datasets of the three most famous satellite-based commercial prediction models (SolarGIS, SUNY, and Solcast) against the observed dataset by six ground stations in Saudi Arabia under different climatic zones. The validation method has been implemented using the standard error metrics: Maximum Absolute Error (MAE) and relative Maximum Bias Error (rMBE). The validation process showed that, in the case of GHI, the discrepancy between observed and predicted values is narrow, while in the case of DNI, the discrepancy is wide. Also, the predicted GHI values are more accurate than predicted DNI values, and -in general- the values predicted by the SUNY model are less accurate than those predicted by SolarGIS and Solcast models for both GHI and DNI. The resultant of this validation process could be accepted not for the six locations under study only but, also for deserts and arid areas across Saudi Arabia and might be extended to similar arid areas around the world.

Modeling and sensitivity analysis of a supersonic inductive Magnetohydrodynamic (MHD) generator

This study presents the supersonic inductive Magnetohydrodynamic (SIMHD) generator and simulates its model through the use of COSMOL Multiphysics. This generator, as an inductive MHD generator, is suggested to address the problems associated with the conventional MHD generator. Since the proposed generator does not require a moving part to convert thermal energy to electrical energy, it is categorized as a direct energy convertor. The SIMHD generator consists of a converging-diverging duct and is divided into two sections at the diverging part by means of a diaphragm. Both of these sections are diverging, which makes it possible to obtain a high Mach number. In this regard, the performance of the SIMHD generator is studied by its mathematical modeling and numerical simulation using the finite element method. In addition, a sensitivity analysis is carried out on the design parameters. The results indicate that the proposed SIMHD duct design will increase the speed from 160 to 1300 m⁄s, and decrease the temperature from 2100 to 1300 K. Moreover, considering a charge generation equation, the produced power for the resistive load 50 Ω equals 25.3 kW. This generator also has the potential to be used in scramjets and ramjets.