Original Article
Photovoltaic Systems
Williams S. Ebhota; Pavel Tabakov
Abstract
This research provides concise insights into fossil fuel consumption challenges, and the factors contributing to global warming, and evaluates the significance of photovoltaic (PV) materials in achieving net-zero-CO2 emissions. The article categorizes constraints in the development of PV cells into four ...
Read More
This research provides concise insights into fossil fuel consumption challenges, and the factors contributing to global warming, and evaluates the significance of photovoltaic (PV) materials in achieving net-zero-CO2 emissions. The article categorizes constraints in the development of PV cells into four main areas: technical factors, leadership impact, political instability, and financial aspects. Primarily, the study delves into technical factors, focusing on the power conversion efficiency (PCE) and power density of PV cells. Theoretically, approximately 67% of solar energy is dissipated in various forms - 47% as heat, 18% as photons, and 2% in local combination loss. Commercially available mono-crystalline silicon (c-Si) and poly-crystalline silicon (poly-c-Si) PV cells typically demonstrate a range of PCEs between 15% to 22% and 13% to 18%, respectively, presenting an efficiency considerably lower than the potential maximum of 100%. The study highlights organic photovoltaic cells (OPVs) as promising third-generation PV modules due to their relatively high power conversion efficiency (HPCE) and eco-friendly attributes. However, their commercial feasibility is under scrutiny owing to constraints such as a limited lifespan, high production costs, and challenges in mass production. Ongoing research and development (R&D) in PV cell technologies aim to enhance PCE and power density, establish cost-effective production methods, and create more reliable and sustainable supply chains. Additionally, the study explores the role of nanotechnology in developing high-power conversion efficiency cells, identifies research gaps and priorities in engineered organic material PV cells, and discusses the potential of OPVs in the R&D of high-efficiency, cost-effective, and environmentally friendly PV cells.
Original Article
Electricity Generation by Green Energy Sources
Rahmat Adiprasetya Al Hasibi; Bagustama Hamka
Abstract
The implementation of on-grid PV systems was conducted to ensure a continuous supply of electricity. This article discusses implementing an on-grid PV system in a fish farm that requires a continuous electricity supply. Continuous electricity is used to power the aeration system. The aeration system ...
Read More
The implementation of on-grid PV systems was conducted to ensure a continuous supply of electricity. This article discusses implementing an on-grid PV system in a fish farm that requires a continuous electricity supply. Continuous electricity is used to power the aeration system. The aeration system is critical in determining whether or not fish farmers can harvest well. An electric motor drives the water wheel in the aeration system, circulating oxygen in the fishpond. Based on the design, operation, and economic parameters, a comparison is made between the proposed system, namely the PV system, and the current system, namely the grid with a diesel generator as a backup. The nominal discount rate, diesel fuel price, and grid reliability level have all been subjected to sensitivity analysis. The Hybrid Optimization of Multiple Energy Resources software was used for the study. The results show that the on-grid PV system can continuously provide electricity to meet the demand for fish farming. The proposed system has a net present cost that is 20% lower than the net present cost of the current system. The cost of energy generated by the on-grid PV system is also 27% less than the cost of energy generated by the current system. Changes in fuel prices do not result in changes in net present cost for all levels of grid reliability to produce continuity in electricity supply. The nominal discount rate strongly influences the net present cost, the higher the nominal discount rate, the lower the resulting net present cost.
Original Article
Geothermal Energy Systems
Prabin Haloi; Ankit Kumar; Joyshree Dutta; Desire Fadzi Makunike
Abstract
The application of a geofluid is primarily characterized by its geofield conditions and locations. One such application of geofluid is in power generation using suitable energy conversion systems. In this study, a thermodynamic model of a double-flash geothermal power plant (DFGPP) has been developed ...
Read More
The application of a geofluid is primarily characterized by its geofield conditions and locations. One such application of geofluid is in power generation using suitable energy conversion systems. In this study, a thermodynamic model of a double-flash geothermal power plant (DFGPP) has been developed to evaluate its performance which is mainly based on the geofluid of the Puga valley of Ladakh region in the Indian peninsula. The present study investigates the possible use of the DFGPP in the region through application of the exergy tool of the second law of thermodynamics. Under the Puga geofluid conditions, the energy and exergy rates, thermal losses, exergy destruction, and thermal and exergetic efficiencies are evaluated. From the thermal analysis results of the DFGPP, the condenser has the maximum energy loss with 97.08% of the overall loss, followed by low pressure turbine (LPT) and the high pressure turbine (HPT) with minimal energy rate losses of 2.28 % and 0.63 % respectively. However, negligible losses in energy are found to occur in the mixing devices, pump and the fluid separators. The maximum rate of exergy destruction occurs in the LPT with 38.95 % and least in the low pressure separator (LPS). The DFGPP operated with energy and exergy efficiencies of 9.52% and 48.39% approximately, producing a net output work of 3.9 MW. The overall cycle exergy destruction is found at 5.4% of the total energy losses. The use of DFGPP systems in the Puga geofield can be a suitable option in power generation.
Original Article
Energy Policy
Nazlı Ersoy
Abstract
The article presents an MCDM model based on the Improved Entropy and PIV methods to analyze the development of renewable energy in Nordic-Baltic countries. The analysis was conducted on eight alternatives and ten criteria, and sensitivity analysis was applied to assess the model's suitability. The impact ...
Read More
The article presents an MCDM model based on the Improved Entropy and PIV methods to analyze the development of renewable energy in Nordic-Baltic countries. The analysis was conducted on eight alternatives and ten criteria, and sensitivity analysis was applied to assess the model's suitability. The impact of 34 different variations in criterion weights on the results was examined. The findings demonstrate that Norway emerges as the most appropriate alternative, and the smallest weight change required to alter the current ranking is 18.93%.
Original Article
Photovoltaic Systems
Niti Agrawal
Abstract
Partial shading condition (PSC) has a detrimental effect on the output performance of a photovoltaic (PV) system. The output performance of a partially shaded PV array depends not only on the pattern, intensity and location of the shadow but also on its configuration. In this paper, the output performance ...
Read More
Partial shading condition (PSC) has a detrimental effect on the output performance of a photovoltaic (PV) system. The output performance of a partially shaded PV array depends not only on the pattern, intensity and location of the shadow but also on its configuration. In this paper, the output performance of two configurations namely- series-parallel (SP), a commonly used configuration, and total-cross-tied (TCT), have been compared under diverse PSCs. A Lambert W-function-based technique has been developed to model, simulate and estimate the performance of both the configurations of the PV array. The developed program can evaluate the current, voltage and power for the arrays of different sizes under uniform and different PSCs. A detailed investigation has been carried out for the output performance of both configurations under nine diverse shading patterns and different sizes of arrays. Comparative analysis for the configurations is presented based on parameters such as maximum power obtained, partial shading power loss percentage, efficiency and fill factor. It has been found from the obtained results that the output performance of a PV array under PSC is enhanced by using TCT configuration compared to SP configuration.
Original Article
Photovoltaic Systems
Christopher T Warburg; Tatiana Pogrebnaya; Thomas Kivevele
Abstract
This study delves into the ongoing discourse surrounding the optimal tilt angles for solar panels to maximize solar PV power generation. Focused on seven equatorial regions in Tanzania; Dodoma, Dar es Salaam, Kilimanjaro, Kigoma, Iringa, Mtwara, and Mwanza. Multiple mathematical models are employed to ...
Read More
This study delves into the ongoing discourse surrounding the optimal tilt angles for solar panels to maximize solar PV power generation. Focused on seven equatorial regions in Tanzania; Dodoma, Dar es Salaam, Kilimanjaro, Kigoma, Iringa, Mtwara, and Mwanza. Multiple mathematical models are employed to ascertain the most efficient panel tilts. Leveraging solar radiation data spanning from 2000 to 2017, we developed an algorithm specifically tailored for computing suitable tilt angles in the southern hemisphere. Our investigation reveals compelling insights into the variation of optimal panel tilts throughout the year. Notably, the monthly optimal tilt angles fluctuate significantly across the regions. June emerges as the month with the highest recorded monthly optimal tilt angle, ranging from 45 degrees in Mtwara to 31 degrees in Kilimanjaro. Conversely, December showcases the lowest tilt angles, spanning from -30 degrees in Mwanza to -26 degrees in both Kigoma and Iringa. Quarterly angles exhibit peaks during the second quarter of the year, reaching 39 degrees in Mtwara and 27 degrees in Kilimanjaro, while experiencing declines in the fourth quarter, plunging to levels between -19 and -24 degrees. Additionally, our study calculates annual optimal tilt angles, revealing a range from 2 degrees in Kilimanjaro to 11 degrees in Mtwara. Crucially, the deployment of monthly optimally tilted solar PV panels demonstrates a noteworthy enhancement, yielding a 6-11% gain in solar radiation compared to horizontally mounted panels. Our study advocates for the adoption of dynamic tilt adjustment strategies of periodic angle alterations to maximize solar PV power generation.
Original Article
Electricity Generation by Green Energy Sources
Mowffaq Oreijah; Hosam Faqeha; Moaz Al-Lehaibi; Kamel Guedri; Sina Hassanlue
Abstract
Distributed electricity generation has been a long-standing focus for researchers and policymakers. With the global rise in electricity demand, various generation methods such as solar, wind, fuel cells, and internal combustion engines—are being implemented, each with distinct advantages and drawbacks. ...
Read More
Distributed electricity generation has been a long-standing focus for researchers and policymakers. With the global rise in electricity demand, various generation methods such as solar, wind, fuel cells, and internal combustion engines—are being implemented, each with distinct advantages and drawbacks. Micro gas turbines have emerged as a viable candidate for a reliable, cost-effective, and accessible energy production system. To enhance overall system efficiency, the heat produced from fuel combustion in these turbines can also be used to generate hot water. This study investigates micro gas turbines fueled by biogas, analyzing the effects of several critical parameters: Turbine Inlet Temperature (TIT), Compressor Pressure Ratio (CPR), and recuperator effectiveness within the cycle. The thermodynamic modeling uses the thermally perfect gas model and was conducted in EES (Engineering Equation Solver), with a selected commercial gas microturbine used for validation. Variable fluid thermodynamic properties are accounted for based on temperature, providing accuracy under diverse operational scenarios. It is found that to achieve the maximum overall efficiency, there is an optimal value for the CPR while it increases with increment in the TIT and recuperator effectiveness.
Review Paper
Photovoltaic Systems
Bandar Mohammad Fadhl; Basim Mohammed Makhdoum; Kamel Guedri
Abstract
Renewable energy systems have received special attention in recent decades, mainly due to the environmental problems of using fossil fuels, fluctuation in the price of these fuels, limitations in their resources, and considerable demand for energy. Solar photovoltaic (PV) modules are among the most attractive ...
Read More
Renewable energy systems have received special attention in recent decades, mainly due to the environmental problems of using fossil fuels, fluctuation in the price of these fuels, limitations in their resources, and considerable demand for energy. Solar photovoltaic (PV) modules are among the most attractive options for power production using solar energy. A variety of factors, including the material, operating conditions, and temperature, influence PV efficiency. Elevation in the cell temperature causes degradation in efficiency and consequently the production of electricity at a constant solar radiation intensity and operating conditions. In this regard, employment of thermal management systems is considered to avoid temperature increments. Hybrid nanofluids, due to their significant thermophysical properties, are attractive options for thermal management of PV cells. This article reviews and presents studies on the thermal management of PV cells. We conclude that different factors such as the type of nanomaterial, cooling configuration, and operating conditions influence the effectiveness of hybrid nanofluids in thermal management of PV cells. Furthermore, reports suggest that the use of hybrid nanofluids, depending on the nanomaterials, may be more effective than single nanofluids in reducing the temperature of PV modules. Applying hybrid nanofluids instead of pure fluids would result in higher energy and exergy efficiencies. Aside from technical benefits, utilization of hybrid nanofluids in PV cooling could be beneficial in terms of economy. For instance, using hybrid nanofluids for module cooling can reduce the payback period of the systems.
Original Article
Photovoltaic Systems
Arash Mahdavi; Mousa Farhadi; Mofid Gorji Bandpy; Amirhoushang Mahmoudi
Abstract
Regulating the operating temperature of photovoltaic (PV) systems is essential for their longevity. An efficient passive cooling method involves the incorporation of Phase Change Materials (PCMs). In this study, a novel nonlinear analytical solution is employed to investigate the melting and solidification ...
Read More
Regulating the operating temperature of photovoltaic (PV) systems is essential for their longevity. An efficient passive cooling method involves the incorporation of Phase Change Materials (PCMs). In this study, a novel nonlinear analytical solution is employed to investigate the melting and solidification processes within the PV-PCM system, which operates continuously for 24 hours each day. The analytical approach significantly reduces computational time to a few seconds compared to over three months required by CFD techniques. The transformation of the partial differential energy equation into a nonlinear ordinary differential energy equation facilitates precise observation of both melting and solidification processes of the PCM material. The analytical approach is further applied to assess the performance of the PV-PCM system during two typical summer days in 2020 and 2021. Additionally, the impact of PCM thickness on the PV-PCM system is examined as a variable input. Results indicate that increasing PCM thickness from 1 cm to 5 cm reduces the peak temperature of the PV module by approximately 7 . This temporal shift is significant, enabling the PV module to operate at cooler temperatures during peak solar intensity, resulting in higher power output. The analytical solution proves instrumental in determining the optimal PCM thickness for a PV-PCM system in any location within seconds. Findings reveal that a 5 cm PCM thickness leads to a 13% decrease in maximum temperature and a 3.4% increase in minimum electrical efficiency. The integration of thermal energy storage enhances the overall efficiency and performance of the PV system.
Review Paper
Energy Policy
Abolfazl Dehghanmongabadi; Zahra Tahmasbnia
Abstract
In recent decades, due to the increase in the urban population and the unbridled growth of urbanization, many efforts have been made to create livable cities by emphasizing the place of renewable energy in the sustainable transportation sector. Using clean, renewable, and sustainable energy resources ...
Read More
In recent decades, due to the increase in the urban population and the unbridled growth of urbanization, many efforts have been made to create livable cities by emphasizing the place of renewable energy in the sustainable transportation sector. Using clean, renewable, and sustainable energy resources is needed to improve social, economic, and environmental health, leading to economic development and productivity. This research tries to clarify the importance of using renewable energy in the transportation sector. In this regard, the main goal of this research is to identify effective indicators and sustainable solutions with an emphasis on the use of renewable energy in the urban transportation sector. Also, in this research, an attempt has been made to answer the questions raised by carefully examining the existing studies based on the scoping review method. The findings show that the extracted influential indicators can be categorized into environmental, economic, and social indicators, which have a significant impact on the use of renewable energy in the transportation sector. Paying attention to this index can increase the amount of use of renewable energy and the amount of desirability of the effective use of urban transportation. Finally, suggestions for strengthening sustainable development in urban transportation systems with an emphasis on the use of renewable energy have been presented.
Original Article
Tide, Wave and Hydro Power
Omid Rasooli; Masood Ebrahimi; Arash Babamiri
Abstract
In the present research, a hydrokinetic turbine is designed, and evaluated technically, economically and environmentally to produce power from low velocity currents. Firstly, the hydraulic characteristics of three existing canals is investigated and the blade profile for the turbine rotor is determined ...
Read More
In the present research, a hydrokinetic turbine is designed, and evaluated technically, economically and environmentally to produce power from low velocity currents. Firstly, the hydraulic characteristics of three existing canals is investigated and the blade profile for the turbine rotor is determined by using the Schmitz's theory and XFOIL software. The geometrical model is then created in the SolidWorks and simulated in the ANSYS Fluent to estimate the power generation capacity. According to the results, a correlation is proposed to estimate the power generation by the turbine in different water velocities. The results are validated with the manufacturers data. The results show that the efficiency of the proposed turbine is almost 90%, the investment payback period is only 3.1 years, with a positive net present value. Environmentally, it shows that for a 1 meter in diameter turbine and water velocity of 1.5 m/s, carbon dioxide will reduce by 0.57 tons per year. The economic and environmental benefits improve greatly at higher water velocities. The results show that the proposed hydrokinetic turbine even by working in low velocity stream can supply electricity demand of rural area near the canals for the long lifespan of the turbine which is more than 25 years.
Original Article
Geothermal Energy Systems
Hiba Mudhafar Hashim; Firas Abed
Abstract
Geothermal energy is one of the important sources of renewable energy, so researchers are greatly interested in this type of energy. One of the advantages of this type of energy is its use to heat or cool buildings because the ground temperature is fairly constant throughout the year. The research focuses ...
Read More
Geothermal energy is one of the important sources of renewable energy, so researchers are greatly interested in this type of energy. One of the advantages of this type of energy is its use to heat or cool buildings because the ground temperature is fairly constant throughout the year. The research focuses on understanding how soil depth affects the temperature difference, the rate of heat transfer, and the overall performance of the system in Baghdad, Iraq, throughout the year by conducting a mathematical test for the ground heat exchanger and determining the number of appropriate requirements during the study to reach an equation that simulates the distribution of temperatures at depth and time. The software package (CFD ANSYS FLUENT) version 17 was used for numerical analysis. The results showed that the heat transfer rate from air to soil for cooling purposes reached its highest value of -1375 watts during July at a depth of 6 m. As for heating purposes, the maximum value during January reached 579 watts at a depth of 10 m and 499 watts at a depth of 6m. Earth air heat exchanger effectiveness was highest possible at depths of 4 and 5 m, ranging from 0.9 to 0.92 over the year. The highest value of 0.98 for the exchanger effectiveness appeared during March. The results showed good agreement between the mathematical and numerical analysis and comparison with other studies, as the percentage of deviation ranged from 1.7% to 3.6% for depths from 1 m to 10 m.