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.
Electricity Generation by Green Energy Sources
Melkior Urbanus; Ghaeth Fandi; Erick Mgaya; Zdenek Muller; Josef Tlusty
Abstract
Electric energy is necessary to meet the daily needs of the population, as it is used in cooking, heating, irrigation, lighting and others. There are many residential areas far from the public electricity network, hence the importance of solar energy in meeting the needs of these residents. This paper ...
Read More
Electric energy is necessary to meet the daily needs of the population, as it is used in cooking, heating, irrigation, lighting and others. There are many residential areas far from the public electricity network, hence the importance of solar energy in meeting the needs of these residents. This paper will study the design of a solar photovoltaic system with a capacity of 131.6 kwh. The needs and requirements will be studied first, then a design will be made for The parts of this system, such as inverters, batteries, photovoltaic panels and other parts. The results that we will obtain will confirm that this energy system is able to meet the necessary needs with high efficiency, and will also confirm that it is environmentally friendly in terms of carbon emissions. We will take Tanzania as a case study , the designed system contain 108 panels and about 8kw battery bank to supply the load .
Solar Thermal Engineering
Zaid Aljohani; Abdulkarim Asiri; Salem Al-Awlaqi; Turki Aljohani; Hossam AbdelMeguid
Abstract
NEOM is a proposed megacity and business zone in Kingdom of Saudi Arabia (KSA). It was announced in 2017 by Crown Prince Mohammed bin Salman with the goal of creating a hub for innovation and a hub for the future of living. NEOM is planned to cover an area of over 26,500 square miles and will include ...
Read More
NEOM is a proposed megacity and business zone in Kingdom of Saudi Arabia (KSA). It was announced in 2017 by Crown Prince Mohammed bin Salman with the goal of creating a hub for innovation and a hub for the future of living. NEOM is planned to cover an area of over 26,500 square miles and will include a focus on sustainability and cutting-edge technology. The project is being backed by the Saudi Arabian government and private investment. The primary objective of KSA is to utilize the renewable energy resources in the NEOM region sustainably. This study evaluates the availability of solar energy in the NEOM region on a quantitative and qualitative basis, and a database of weather conditions such as temperatures and wind speed is collected and processed. NEOM has favorable climate conditions with an average annual radiation incident energy of 12.54 GJ/m2, wind speed of 15.68 km/h, and temperatures ranging from 16 to 38°C. Based on the analyzed data, the study investigates the potential of solar energy as a sustainable source and alternative to conventional fossil fuels. The utilization of solar energy could be applied in various ways including seawater humidification-dehumidification (HDH) desalination with productivity of 26-33 l/day/m2, solar cooling with an average load of 15 MJ/day/m2, green hydrogen production with rate of 41-47 mole/day/m2, and electrical power generation with rate 4.2-6.8 MJ/day/m2.
Photovoltaic Systems
Mustafa Arslan; Mehmet Cunkas
Abstract
Diffuse radiation is used in photovoltaic systems and other energy applications. Since global radiation is measured by local meteorological stations, it is possible to reach these radiation data. However, diffuse radiation is not usually measured, so it is not possible to obtain regular data on diffuse ...
Read More
Diffuse radiation is used in photovoltaic systems and other energy applications. Since global radiation is measured by local meteorological stations, it is possible to reach these radiation data. However, diffuse radiation is not usually measured, so it is not possible to obtain regular data on diffuse radiation. For this reason, efforts are underway to develop various empirical models to estimate diffuse radiation. This paper aims to develop new empirical models to estimate the diffuse radiation values for Konya, Türkiye. The empirical models are used to determine the relationship between the diffuse fraction and the clearness index. Data from NASA-Surface meteorology and Solar Energy and the measured global solar were used. The three most suitable developed models were selected, and it was suggested to estimate the diffuse radiation. The developed models consist of 2nd, 3rd, and 4th-order polynomial regression models. The proposed models were tested to evaluate their performances by using eight statistical methods. These are Mean Bias Error (MBE), Mean Absolute Error (MAE), Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Sum Squared Relative Error (SSRE), Relative Standard Error (RSE), Coefficient of determination (R2) and Correlation Coefficient (r). For the suggested models, the statistical parameters R2 value were calculated as 0.999705413, 1, and 1, and the RSE values were determined as 0.0084537, 0.000122, and 6.05E-06. The proposed models can contribute to researchers working on the applications of photovoltaic systems. The approaches could be used to estimate diffuse radiation elsewhere under similar climatic conditions.
Ruben Felix; Leonidas Sayas
Abstract
Plenty of works have treated the system expansion planning problem in the presence of intermittent renewable energy resources like solar. However, most of those proposals have been approached from scenarios of plenty of data, which is not the rule in developing countries, where principal investment actors ...
Read More
Plenty of works have treated the system expansion planning problem in the presence of intermittent renewable energy resources like solar. However, most of those proposals have been approached from scenarios of plenty of data, which is not the rule in developing countries, where principal investment actors have recently switched their focus. In contrast of operation problems where existing literature can be successfully applied since it requires short-term historical time-series gathered from the same studied plants, proposals for planning problems are almost impossible to apply because of a lack of information and measurement about renewable resources in places where no renewable plants have been previously installed. In order to fill this information gap, this paper presents a novel methodology to synthesize solar production time-series on an hourly time scale, taking as inputs aggregate data such as monthly average, maximum or minimum values of basic parameters like global horizontal insolation, air temperature, and surface albedo. The methodology comprises five steps, from data gathering to calculating electrical power produced by a solar photovoltaic system. Three application tests are performed for different places in Chile, Slovakia, and Peru to validate the proposed methodology. The results show that the methodology successfully synthesizes time-series of output power, correctly replicates typical solar resource behavior, and slightly underestimates the produced solar energy, having a discrepancy of 2.4% in the yearly total.
Energy Policy
Z. Molamohamadi; M.R. Talaei
Abstract
This paper aims to analyze and identify the most appropriate strategies to deploy solar energy in Iran. For this purpose, in a comprehensive framework of strategy development, the internal and external factors of general and specific environment were determined. Then, four different strategies, including ...
Read More
This paper aims to analyze and identify the most appropriate strategies to deploy solar energy in Iran. For this purpose, in a comprehensive framework of strategy development, the internal and external factors of general and specific environment were determined. Then, four different strategies, including aggressive (strong expansion and development), conservative (maintaining, internal protection), competitive (maintaining, external protection), and defensive strategies (withdrawal, reduction of costs, ceasing on investment, joining another corporation), were considered using internal-external and SWOT (Strengths, Weaknesses, Opportunities, and Threats) matrices. According to the numerical results of the internal and external factor evaluations, which are 2.74 and 3.06 respectively, the aggressive strategies would be acceptable for Iran. However, since the location of these values in the internal-external matrix is close to the conservative cell, the effective strategy for the present condition of our country is a combination of aggressive and conservative strategies.
G. Jafar Laame; W. Rahimy; S. Yerel Kandemir; E. Acikkalp
Abstract
Energy is an essential need for living, and renewable energy sources are increasingly popular sustainable energy sources. Solar energy is an inexhaustible and clean, sustainable energy source in the world. In this study, heating of a greenhouse in Herat (Afghanistan) with a heat pump using solar energy ...
Read More
Energy is an essential need for living, and renewable energy sources are increasingly popular sustainable energy sources. Solar energy is an inexhaustible and clean, sustainable energy source in the world. In this study, heating of a greenhouse in Herat (Afghanistan) with a heat pump using solar energy was investigated. The greenhouse was kept at 20 oC, and the electricity required to operate the heat pump was taken from the grid. As a result of the analysis, the exergy/electricity input reaches 25.59 kWh, while the minimum values are equal to 0.01 kWh. It was determined that the product exergy went maximum product exergy of 6.38 kWh. Finally, it was determined that a ground source heat pump with a higher COP could be used instead of an air source heat pump.
Sakhr M. Sultan; C. P. Tso; Ervina Efzan M. N
Abstract
A case study is conducted to evaluate the photovoltaic (PV) performance in a horizontal and in an inclined PV solar thermal collector (PVT) for two different PVT geometries; the series flow and the parallel series flow. It is shown that the series flow gives a better photovoltaic performance at a horizontal ...
Read More
A case study is conducted to evaluate the photovoltaic (PV) performance in a horizontal and in an inclined PV solar thermal collector (PVT) for two different PVT geometries; the series flow and the parallel series flow. It is shown that the series flow gives a better photovoltaic performance at a horizontal PVT surface as compared to the parallel series flow. At mass flow rate of 0.03 kg/s and zero inclination angle (horizontal PVT surface), the PV efficiencies are 14.32 % and 14.25 % for series and parallel series flow, respectively. But for an inclined PVT surface, the parallel series performs better than that of the series flow. At mass flow rate of 0.03 kg/s and inclination angle of 45 °C, the PV efficiencies are 13.76 % and 13.87 % for series and parallel series flow, respectively. It can be concluded that the inclination angle is one of the essential parameters that can be used to evaluate any PVT design and make better comparison between different designs. It is also beneficial for researchers and PVT product designers to know the effectiveness of their collector designs for cooling the PV panel at the early product design stage and to base on the optimum inclination angle of the region.