Electrical Energy Production Research Articles

Evaluation of the Duration of Albedo Measurement Campaigns

Bifacial PV modules are increasingly used in commercial solar PV projects. With the use of the solar energy available at the module’s rear surface, the correct estimation of the albedo during the pre-construction phase of commercial projects becomes more important. The intention of the study is to determine the impact of the duration of a short-term albedo measurement campaign to reduce the uncertainty with respect to satellite albedo, thus providing a ‘beneficial campaign’. Albedo measurements from seven sites in the USA have been used to estimate the impact of 1-day and 7-day measurements (short-term measurements) on the simulated annual electrical energy production. Simulations based on monthly albedo data obtained from a recognised satellite provider have been compared with simulations where the albedo has been corrected based on short-term measurements. The study found that a 1-day campaign is often not beneficial, causing an increase in uncertainty with respect to satellite albedo. Measurement campaigns in winter do not generally reduce the error of the annual electrical energy production simulation, however, a 7-day campaign undertaken in summer appears to often reduce the uncertainty. It should be noted that the climate conditions, ground vegetation and measurement setup of the analysed seven sites in the USA may not be representative for other sites in the rest of the world.

Shielding factors for a fission-powered mars exploration rover

Background With the advances in compact fission power systems and Stirling converters, the efficiency and portability of electrical energy production systems has increased substantially thanks to NASA’s Kilopower project. These 1-10 kWe-class reactors are compact enough to be transportable by pressurized rovers, allowing an extended human reach across the surface of Mars to produce scientific data at a rate that greatly surpasses the rate of robotic rover data collection. If rovers were to harness fission power while mobile, it is possible for near-limitless range. This capability could allow one crew on Mars for under a “Conjunction” class mission as outlined in NASA’s Mars Design Reference Architecture (DRA) 5.0 to visit many geological sites of interest instead of requiring additional landings to explore distant features of the Martian surface. This study explored the parameters that affected the mass of the shielding required to protect the crew against a fission reactor embedded in the chassis of a pressurized rover. Methods An analytical approach was devised to estimate the required mass of a hypothetical solid tungsten shield under various conditions. Results Power levels below 3.4 kWe were found to be impractical for rover applications. Between 3.4 kWe and 10 kWe would be able to recharge the rover without returning to base camp. The increase in shielding mass from a 3.4 kWe reactor and a 10 kWe reactor was 6%. The reduction between a 10 kWe reactor at 3 m and 6 m was 7%. Varying the shield thickness in accordance with astronaut activities resulted in a 19% reduction. Powering the reactor off before exiting the vehicle resulted in an additional 65% reduction. Conclusions Knowledge of the crew activities and locations had the greatest impact on the required shielding mass and the mission activities should be well-understood and taken into account for shield design.

Tweaking the redox properties of PpcA from Geobacter metallireducens with protein engineering

Geobacter’s unique ability to perform extracellular electron transfer (EET) to electrodes in Microbial Fuel Cells (MFCs) has sparked the implementation of sustainable production of electrical energy. However, the electrochemical performance of Geobacter’s biofilms in MFCs remains challenging to implement industrially. Multiple approaches are being investigated to enhance MFC technologies. Protein engineering of multihaem cytochromes, key components of Geobacter’s EET pathways, can, conceivably, be pursued to improve the EET chain. The periplasmic cytochrome PpcA bridges ET from the inner to the outer membrane and its deletion impairs this crucial step. The functional characterisation of PpcA homologs from G. sulfurreducens (Gs) and G. metallireducens (Gm) revealed a significantly different redox behaviour even though they only differ by thirteen amino acids. In a previous study, we found that the single replacement of a tryptophan residue by methionine (W45M) in PpcAGm shifted the reduction potential value 33% towards that of PpcAGs. In this work, we expanded our investigation to include other non-conserved residues by conducting five mutation rounds. We identified the most relevant residues controlling the redox properties of PpcAGm. With just four mutations (K19, G25, N26, W45) the reduction potential value of PpcAGm was shifted 71% toward that of PpcAGs. Additionally, in the quadruple mutant, it was possible to replicate the haem oxidation order and the functional mechanisms of PpcAGs, which differ from those in PpcAGm. Overall, the mutants exhibit diverse redox and functional mechanisms that could be explored as a library for the future design of minimal, synthetic, ET chains in Geobacter.

Fault-tolerant cascaded H-bridge inverter connected to power grid

Nowadays, the use of inverters is increasingly required in domestic and industrial installations, electrical energy production plants, and in several other areas for the conversion from the DC form to the AC form of the electrical energy such as aviation, maritime and especially in the field of Parallel Active Filtering where it constitutes the capital element for the injection of harmonic compensating energy into the electrical network. In the interest of ensuring its reliability and especially its availability, it is therefore important to design its fault-tolerant model. In this paper, we propose a new model of cascaded H-bridge inverter which could even in the presence of faults, continue to deliver a voltage of value equal to that in normal operating mode. The results of simulations carried out using the Matlab/Simulink software show good performance of the proposed inverter.

Model of optimizing operating modes of autonomous power supply systems based on hydrogen technologies for the needs of the Arctic

The possibilities of implementing a “hydrogen transition” in the local energy sector of the Arctic are considered based on the application of the concepts of environmentally friendly technologies and socio-technological transit according to the criterion of profit maximization. The relevance of the work is due to the reform of the electric power industry, which implies a phased transition to a competitive market model, when each manufacturer will be interested in maximizing its own profit and independently determine the volume of production of electrical and thermal energy based on modern technologies. An analysis of foreign experience in creating autonomous hybrid power systems was carried out. The article discusses the possibilities of using hydrogen produced from natural gas in fuel cells in decentralized electricity and heat supply systems. The conditions for the competitiveness of the new technology in comparison with centralized systems and decentralized ones based on mini-CHP with gas turbine or gas piston engines have been determined. It has been shown that fuel cell systems using natural gas as fuel are not energy-saving technologies, but can reduce emissions of carbon dioxide and other pollutants into the environment. Massive use of fuel cells in decentralized energy supply systems is possible only if their cost is reduced to less than $100/kW.

The Effect of Kuwait’s Climate on the Efficiency of Solar Cells in the Electricity Production Network (A Theoretical Study)

The research aims to demonstrate the climate impacts in Kuwait on the efficiency of solar cells in the electricity production network, and to analyze climate constraints and problems related to the use of solar energy in electricity production. The study specifically aims to demonstrate the impact of high temperatures and the potential effects of sand and sandstorms, and certainly to find potential technical solutions. To increase the efficiency of solar cells in Kuwait’s climatic environment, based on the importance of the topic as it is an addition to engineering studies, as it highlights the benefits of using solar energy in producing electricity, and through the use of the descriptive approach and the analytical approach, several results were reached, the most important of which was, The high temperature under which solar panels operate is one of the most important factors that affect their productivity, and The methods of installing solar cells may affect their exposure to solar radiation, which affects the efficiency of electricity production, The study recommends using smart prediction systems based on AI and programming these systems to operate only when temperatures rise above certain levels to save energy. We also recommend using machine learning to perform preventive and regular maintenance and monitor the performance of solar panels.

Techno-economic viability of sustainable solar co-generation using CPV cells in parabolic dish concentrators: A 20-year perspective

Solar co-generation is a cutting-edge technology that enables the instantaneous production of electricity and heat energy by employing concentrated solar power (CSP) systems. This study presents the development and experimental analysis of a novel small-scale solar co-generation system, utilizing concentrated photovoltaic (CPV) cells integrated into a solar paraboloidal dish concentrator (SPDC) for simultaneous electricity and heat production. The system, designed with a high concentration ratio, employs a CPV module composed of four 1 cm × 1 cm cells mounted on a flat receiver of a parabolic dish concentrator with an aperture area of 12.6 m2. Experimental results, obtained over three consecutive days, demonstrate that the CPV module achieves an electric power output ranging from 480 to 645 W daily, while the SPDC system generates thermal energy between 395 and 725 W. The economic analysis indicates a cost of ₹10.75 per unit of electricity, with a payback period of approximately 13.5 years, assuming a 20-year system lifespan. Additionally, the reliability of the CPV module and the impact of varying encapsulation materials were critically assessed, providing insights into potential improvements and long-term performance. The findings underscore the viability and economic potential of solar co-generation systems employing CPV technology, contributing to the advancement of sustainable energy solutions.

Assessment of merits and demerits of perpendicular and slanted photovoltaic/thermal facades

This study compares the thermal and electrical energy production potential and wind load assessment of perpendicular versus slanted photovoltaic (PV) facades. The goal is to identify the optimal facade orientation for societal adoption based on energy efficiency and wind load considerations. Using Hybrid RANS/LES models, the aerodynamic performance and energy yield of both orientations are analyzed under varying angles and environmental conditions. The findings show that while the slanted façade is better designed to capture solar irradiance, it produces 4 to 8 % less energy than the perpendicular façade and yields approximately 2 % less exergy efficiency due to wind regime. However, the slanted design reduces wind load by 9.8 %, enhancing structural stability. The maximum thermal energy output of 217 kW is recorded from the perpendicular façade at a wind speed of 1 m/s, while the slanted façade generates a peak electrical power of 68 kW at 8 m/s wind speed. Overall, the perpendicular façade underscores more efficient in equal weather conditions, making it a sustainable choice for PV installation. These results provide valuable insights for architects, engineers, and policymakers in optimizing PV facade design for urban environments.

Control Performance Assessment of a Zero Harmonic Distortion Grid-Forming Converter for Medium Voltage Islanded Microgrids

The world is currently witnessing a rapid transformation in the production and utilization of electrical energy. The traditional centralized generation model for electric power is swiftly evolving into a more decentralized system, known as Distributed Generation (DG), which incorporates renewable energy sources situated closer to end-users. This shift towards DG has paved the way for the emergence of grid-forming converters, which play a pivotal role in enhancing voltage and frequency stability within microgrids (MGs) and isolated applications. This study focuses on assessing the performance of the Zero Harmonic Distortion (ZHD) in both stand-alone and parallel operation modes. The distinctive feature of this converter lies in its inherent ability to generate a sinusoidal voltage source without the need for capacitive filtering components, which can adversely affect cost, efficiency, and size while potentially contributing to resonance problems. This is achieved through a judicious combination of harmonic cancellation within a three-winding transformer and the utilization of Selective Harmonic Elimination Pulse Width Modulation (SHE PWM) dismissing a closed-loop control structure. Simulation and hardware-in-the-loop results presented in this work demonstrate the satisfactory performance of the ZHD grid-forming converter.

ОБҐРУНТУВАННЯ КОМПЛЕКСНОГО ПРОЕКТУ ВИРОБНИЦТВА ТЕП-ЛОВОЇ ТА ЕЛЕКТРИЧНОЇ ЕНЕРГІЇ З ВИКОРИСТАННЯМ МЕТАНУ ЗА-КРИТИХ ШАХТ

The article deals with the issue of methane extraction from closed mines for its further use as an alternative energy source. A substantiated and developed method of methane extraction from the dome of the collapse of closed mines, while a mobile surface degassing unit is used to extract methane from the installed places of gas collectors. The use of the proposed method of methane extraction will improve the environmental safety of the man-made and natural environment, solve the issue of disposal and use of methane as fuel for cogeneration plants. To ensure the company's own production of electricity and thermal energy, a gas-piston cogeneration power plant has been justified and selected.At the first stage of the project, methane reserves of closed mines are calculated. As a result of the collapse of the roof layers above the created space in the mountain massif, a displacement vault and a "collapse dome" are formed. Methane accumulates under the collapse dome. The parameters of the vault depend on the depth of the cleaning work and the size of the created space. At the second stage, a mobile surface degassing unit is used to extract methane from closed mines from established places of methane accumulation. The advantage of a mobile surface degassing unit is its mobility, which makes it possible to install it in the necessary places, as well as carry out degassing and achieve significant volumes of capted gas with a methane content of up to 80%. To obtain a gas-air mixture of the required concentration (from 25% to 40%), a methane concentration increaser is used. The third stage is the substantiation of the type of power plant for the design of a gas turbine or gas piston mini thermal power station, taking into account individual conditions and technical tasks.

Effect of the use of metal–oxide and boron-based nanoparticles on the performance in a photovoltaic thermal module (PV/T): Experimental study

Renewable energy sources are constantly on the agenda because the fossil fuels used are limited and the need for energy is constantly increasing. Among these resources, solar energy stands out because it is clean and endless energy. Nowadays, heat energy and electrical energy production from solar energy are quite common. Photovoltaic (PV) solar panels can convert a limited portion of the solar energy falling on them into electrical energy. In PV panels, heat energy that cannot be converted into electricity is discharged back to the external environment. Photovoltaic thermal (PV/T) panels are used to remove this heat from the system and convert it into useful energy. Many cooling techniques are applied to reduce the surface temperature of PV/T panels and increase their electrical efficiency. One of these techniques is liquid-cooled PV/T panels. In some of the studies, forced circulation (using a pump) and in others natural circulation (thermosiphon effect) were applied. In this study, a natural circulation indirect heated PV/T system was designed. Al2O3, ZnO, and BN nanoparticle concentrations were added to the cooling water to increase heat transfer within the PV/T panel. According to the experimental results, using nanofluid in the PV/T panel increased the thermal and total efficiency. Total efficiencies of ZnO, BN, and Al2O3 were obtained as 52.8 %, 47.86 %, and 43.49 %, respectively, at 0.03 concentration. The highest exergy efficiency and sustainability index were determined as 17.155 % and 1.207, respectively, at 0.03 concentration of ZnO nanofluid.

A Thermodynamic Comparison of Exergy Production from Sugarcane and Photovoltaic Modules in the Context of Brazilian Energy Transition

This article applies the exergy analysis to the production and use of sugarcane, considering a model published in the literature. In this way, we compute incident solar irradiation, carbohydrate production, water consumption, and the production of stalks and straws. Following the production estimate, we analyze a biorefinery production cycle, from solar irradiation to the biorefinery products on an exergy basis, from birth to production of sugar, electrical energy, and ethanol. The calculated sugarcane production values are 80.7 tons per hectare for a 52-week cycle. As a result, the average exergy efficiency of sugarcane is 4.99%, reaching peaks of 8.3%. When considering only the useful exergy generated in the production of stalks and straw, an annual yield of 17.86 kWh/m2 represents an overall exergy efficiency of 1.31%. Considering the energy conversion processes in the biorefinery, the exergy efficiency from the radiation to the products from the biorefinery was 0.38%. The photovoltaic modules already have a well-established application in the country, though they need to increase their insertion over time, whereby the panels exhibit an average exergy efficiency of 31.6%, resulting in an annual electrical energy production of 255.84 kWh/m2. The results show that photovoltaic modules are a more efficient alternative than sugarcane regarding exergy land use. In conclusion, this study briefly discusses the use of sugarcane and photovoltaic modules in the context of Brazil’s energy transition towards a reduced dependence on fossil fuels, based on the fact that sugarcane already has a low carbon footprint for transportation using ethanol, with supply from more than 40,000 stations, and a similar or lower carbon footprint than electrical vehicles used across the country.

Beam energy recovery in Neutral Beam Injections and related simulations

The Neutral Beam Injectors (NBI) will be used to further increase the plasma temperature for the ignition of the fusion reactions in the ITER project. For future applications of electric energy production, the NBI efficiency is crucial. Since the gas neutralizer gives large residual ion fractions of D+ and D-, adequate energy recovery systems may be necessary. Recently a conceptually simple beam energy recovery based on space charge effects has been proposed; it can also work as an ion dump device, with advantages in removing the residual ions with reduced power dissipation. Preliminary simulation results were evidence of that the proposed device can remove all the residual ions by collecting them at very low energy on proper electrodes. In this contribution, further simulations with more accurate space charge calculations are reported to mostly confirm the high residual ion collection efficiency obtained in the preliminary simulations. The simulated operation voltage is also increased from 20 kV to 500 kV in steps. Higher efficiencies require some increase of the collector length, especially at higher operation voltage, as here discussed. Some design detailed features are also updated.

A CO2-emission free direct methanol fuel cell for simultaneous production of electrical energy and value-added chemicals

It remains challenges to efficiently convert carbon-based fuels such as methanol from CO2 into electrical energy while without CO2 greenhouse gas emission. Herein, a CO2-emission free direct methanol fuel cell (DMFC) has been realized through using unique Pt-CoOOH/nickel foam anode with high electro-catalytical selectivity, activity and stability. The DMFCs demonstrate simultaneous production of 18 mol of formate for every 1 kWh of electricity output with peak power density of 49.3 mW cm−2 and high selectivity of formate value-added chemicals up to 96 %. Moreover, this simple procedure does not consume energy while output electricity compared to the traditional formate production. It either does not use the toxic feedstock of CO and the reaction conditions are very mild. The in-situ Raman test indicates that CoOOH acts as an auxiliary active site to promote the conversion of *HCO to *HCOOH and improve the selectivity of formate. In-situ IR tests and density functional theory (DFT) calculations confirm that methanol tends to be oxidized selectively into formate rather than complete-oxidizing into CO2. This study achieves clean and efficient utilization of carbon-based fuels to co-generate electrical energy and value-added chemicals while no CO2 greenhouse emission, even realize the “negative carbon” cycle.

Design-Optimization of Solar-Collector Tilt Angle for Annual-Maximum and Seasonal-Balanced Energy Received

Abstract A detailed research study was performed on the annual energy received by a fixed-tilt solar collector. A new clear-sky model of solar radiation was developed by combining existing clear-sky models. Then, this model, was used to perform optimizations with two different objectives. The first objective is to achieve the maximum-annual solar energy received by a solar panel, while the second is to balance its energy received so that it is more uniform over the course of a year. Each of these objectives have differing optimum tilt values, depending on the location and usage of a solar receiver system. The novelty of this investigation is the use of the aforementioned solar model with a unique algorithm for multiple optimizations for these two different objectives, which results in two different optimum tilt angles that are in turn different from the widely accepted rule-of-thumb that recommends an angle that is equal to the latitude. The solar radiation results obtained with the model used herein were experimentally confirmed through comparison with measured weather data for a number of locations with different sky clearness indexes as well as comparison with those of other studies found in the literature. A major contribution of this study are the plots and tables showing optimum tilt angles as estimated by the model as well as with empirical data. By selecting the appropriate tilt angle, a designer can now decide to either maximize annual electrical energy production or else to balance delivery of electricity over the year.

Environmental Limitations of the Use of Solar Energy in the Carpathian Region

Abstract. The purpose of the work is to study the environmental limitations of using solar energy in the Carpathian region of Ukraine. Problem. A number of main restrictions affecting the location of solar power plants are highlighted, which are analyzed in the process of carrying out a strategic environmental assessment and are substantiated by calculation in the process of the environmental impact assessment procedure. For solar power plant projects, the main environmental limitation is the use of land areas. In the Carpathian region, plots under solar power plants must bypass agricultural land, recreational and touristic use, buffer zones of nature reserves. An important technical limitation is the ability to connect solar power plants to electrical networks. Methodology. In the course of the research, the regression analysis of the dependence of the amount of electricity produced by the experimental solar power plant at the Ivano-Frankivsk National Technical University of Oil and Gas on meteorological parameters was further developed using statistical processing of a series of observations. Results. Originality. It was determined that the air temperature has the greatest influence on the production of electrical energy with a correlation coefficient of 0.919. A direct linear relationship indicates an increase in power generation with an increase in air temperature up to +250C. Relative humidity has a fairly significant effect on the generation of solar energy. The resulting correlation coefficient of 0.776 indicates a close relationship between the two data series. When the humidity increases to 76%, the production of electricity by solar photovoltaic panels increases and decreases with a further increase in humidity from 75 to 100 %, which is associated with an increase in cloudiness under such weather conditions. Wind speed also has a strong correlation with solar power generation. Electricity production increases in conditions of low wind or almost windless weather with a wind speed value of up to 2.9 m/s and decreases with a further increase in wind speed. Practical value. The obtained significant regularities will be of practical importance for the justification of environmental restrictions when using solar energy for the conditions of the city of Ivano-Frankivsk.

A Comparative Study of Artificial Neural Network Training Algorithms to Predict Photovoltaic Module Output Power

Introduction: Solar energy is a crucial component and contributes a large portion of renewable resources, the demand for which has recently increased. During previous years, it was difficult to predict the amount of energy obtained from photovoltaic systems. The angle of inclination of the solar panel, the amount of radiation, the speed of the wind, the amount of humidity, and the temperature of the weather are major factors that effectively affect the production of electrical energy. Scientists have used many strategies to predict the power generated by PV modules accurately, but each method has different pros and cons. Method: This study tested three training algorithms for artificial neural networks (ANN): scaled conjugate gradient (SCG), Levenberg Marquardt (LM), and Bayesian regularization (BR), determining which one performed best in terms of prediction speed and accuracy. Twenty-eight thousand two hundred ninety-six samples of experimental data for primary influencing environmental factors were fed into the artificial neural network, which consists of 15 hidden layers. Before training the network, we preprocessed the data to remove factors that have a secondary effect. Result: The analytical results showed that the artificial neural network trained according to the LM algorithm is the best in terms of accuracy and speed of predicting the resulting photovoltaic energy. Conclusion: The results showed that although the regression evaluation and MSE values for the LM, SCG, and BR algorithms are close (98.129%, 0.0622, 97.849%, 0.0587, 98.151%, and 0.0585, respectively), the LM training algorithm is the best in terms of speed of calculation and display of results.

Collision of Environmental Expectations when Assessing the Supply Versus the Consumption of Electrical Energy

The use of energy supplies for economic activities is a major global concern due to its environmental impact. Mitigating this problem involves the adoption of clean energies, so it is not trivial to assess those that can fit into this category, particularly the part corresponding to electrical energy. While the consumption of the latter is often perceived as more environmentally friendly than other sources, its production process raises significant questions, hence the core motivation to evaluate the behavior of the main inputs for electrical energy production over 50 years and its correlation with the world Gross Domestic Product (GDP), confirming a prominent dependence on fossil fuels, a situation that seems to differ from the expectations set forth through the Paris Agreement and the United Nations Conference of the Parties. On the other hand, even though the production of electrical energy is consistent with the behavior of the world GDP, it shows heterogeneous annual percentage changes.

Optimizing biomass energy production in the southern region of Iran: A deterministic MCDM and machine learning approach in GIS

This study employs a deterministic approach, distinguishing itself from other renewable energy evaluations, to assess the potential of electrical energy derived from biomass sources in the southern region of Iran. The primary objectives include pinpointing optimal locations for maximal biomass production and subsequent energy generation within distinct climates and topographies, using fuzzy- Analytic Hierarchy Process (AHP). Additionally, Principal Component Analysis (PCA) identify key factors influencing biomass and energy production. The study quantifies electrical and thermal energy derived from biomass sources across various climates. The findings indicate that regions with lower altitudes and humid climates (1530 km2) demonstrate superior biomass performance, leading to increased electrical and thermal energy production. The feature selection process highlights the significant impact of climate and soil characteristics on biomass production and energy output. Analysis of biomass energy production reveals maximum electrical energy production ranging from 674.88 kWh/ha to 711.36 kWh/ha. The results of the Long Short-Term Memory (LSTM) method confirm its high accuracy in estimating electrical energy, with a significant correlation coefficient of 0.98. We conclude that by identifying locations with the best biomass sources based on climate, it is possible to increase the derived electrical energy. These insights are critical for informing energy policies aimed at optimizing biomass energy production and its integration into sustainable power grids.

Supporting strategy for investment evaluation of photovoltaic power generation engineering projects using multi-criteria decision analysis methods

This scientific study examines the evaluation of photovoltaic power generation projects through the application of multi-criteria decision analysis methods. Two groups of large-scale grid-connected PV power generation system projects with a nominal power of 50 MW and 500 MW respectively were analyzed and evaluated. These systems were designed to be installed in the same wider geographical area in northern Greece, but they were differentiated in the part of the PV circuit. Twelve systems were analyzed in which either monocrystalline silicon panels or poly-crystalline silicon panels or bifacial photovoltaic panels were to be installed. In these systems either central photovoltaic inverters or photovoltaic string inverters were considered for installation. The following criteria were used to evaluate the investment in these projects. These criteria were related to the profitability, the financial cost, the technical level, and the electrical energy production of the systems and these were the initial investment cost, the operation and maintenance cost, the levelized cost of electricity, the net present value, the internal rate of return, the capital recovery or payback period, the technical level of the photovoltaic circuit, the technical maturity of the photovoltaic circuit, and the annual electricity production. The evaluation of these criteria was initially conducted with fixed weighting coefficients followed by a sensitivity analysis of these weighting coefficients. The results of the evaluation using the PROMETHEE, AHP and TOPSIS multi-criteria decision analysis methods showed that the PV power generation systems which should be preferred are those with increased nominal power, where monocrystalline silicon technology panels are employed following the central inverter topology.