Renewable Energy Resources and Technologies
Sepideh Rahmati Dehkordi; Mehdi Jahangiri
Abstract
In Iran, due to the problems and constraints of fossil fuels and the need to maximize the use of solar potential, one of the best ways is the application of photovoltaic systems integrated with buildings. Due to the significant dependence of solar cell performance on the availability of radiation, it ...
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In Iran, due to the problems and constraints of fossil fuels and the need to maximize the use of solar potential, one of the best ways is the application of photovoltaic systems integrated with buildings. Due to the significant dependence of solar cell performance on the availability of radiation, it is necessary for architects to have an accurate assessment of the amount of electricity produced in different conditions. Therefore, in the present work, using HOMER software, the energy-econo-Enviro (3E) potential of a Building Integrated Photovoltaic (BIPV) in Abadan was studied. The effect of slope and azimuth of solar cells as well as cloudiness and system losses were investigated using sensitivity analysis. The results showed that the PV-grid system was the most economical option and after the azimuth angle of zero degree, the positive azimuth angle was the most economical. The results also showed that the slope of 30 degree and the angle of azimuth equal to zero was appropriate, for which the price per kWh of generated electricity was calculated to be $0.09. For the use of solar cells in the vertical wall of the building, the southwest direction was the most suitable and based on the results, it was suggested that the western wall of the building should be in the form of “inclined PVs with windows”. The authors of this paper hope that the results of the present work can be used by architects and energy decision-makers as a guide in developing the BIPV use in Iran.
Renewable Energy Resources and Technologies
Aloys Martial Ekoe A. Akata
Abstract
Photovoltaic energy has the potential to become one of the major energy sources used in the households in the tropical region of Africa, where the solar radiation intensity is abundant and almost constant over the year. Solar photovoltaic systems present many advantages when they are integrated in the ...
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Photovoltaic energy has the potential to become one of the major energy sources used in the households in the tropical region of Africa, where the solar radiation intensity is abundant and almost constant over the year. Solar photovoltaic systems present many advantages when they are integrated in the building structure envelope and have a significant influence on the indoor air temperature of dwelling buildings due to the thermal resistance modification. In this paper, a simplified model of the photovoltaic system integrated on the roof of a residential building according to the building construction customs and materials has been designed and modeled. The heat transfer is studied in several situations: with and without a Building Integrated Photovoltaic (BIPV) system and for a building with and without false ceiling. The BIPV system installed over an effective area of 35 m2 increases the building indoor air temperature of approximately 5 °C which is corrected by the heat insulation optimization of the false ceiling made up with building local materials. The final indoor air temperature obtained is in good agreement with the ASHRAE standards and can, therefore, be applied to tropical regions.
Renewable Energy Resources and Technologies
Stephen Ndubuisi Nnamchi; Onyinyechi Adanma Nnamchi; Kevin Nnanye Nwaigwe; Zaid Oluwadurotimi Jagun; Johnson Ugochukwu Ezenwankwo
Abstract
This study conducts a comparative evaluation of the performance of modules and the arrays under standard test conditions. An equivalent circuit model was developed alongside a computational scheme. The model input data were obtained from the manufacturer’s specification datasheets. They were used ...
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This study conducts a comparative evaluation of the performance of modules and the arrays under standard test conditions. An equivalent circuit model was developed alongside a computational scheme. The model input data were obtained from the manufacturer’s specification datasheets. They were used to analyse the maximum Fill Factor (FF) and Relative Power Losses (RPL) for Parallel (P), Series (S) and Series-Parallel (SP) configurations. For matching modules, the RPL was insignificant, but for mismatched modules, the parallel configuration (P) and series-parallel (SP) yielded RPL of 1.3 %, while the series configuration (S) produced RPL of 2.6 %. Thus, short circuit defects associated with the P and SP configuration were well below the open circuit defects associated with the series configuration (S). These results clearly show that the large photovoltaic plant needs to be configured with multiple blocks or strings of SP configuration in order to suppress RPL. In addition, the designer and installers of large solar power plants should adopt modules with uniform electrical and thermal properties in the construction of large solar power plants. The trivial RPL associated with the matched modules should be taken into consideration, as well.
Renewable Energy Resources and Technologies
Seyed Ali Akbar Fallahzadeh; Navid Reza Abjadi; Abbas Kargar; Frede Blaabjerg
Abstract
This study investigates a new double-stage single-phase Grid-Connected (GC) Photo-Voltaic (PV) system. This PV system includes a DC-DC Positive Output Super Lift Luo Converter (POSLLC) and a single-phase inverter connected to a grid through an RL filter. Due to its advantages, the POSLLC was used between ...
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This study investigates a new double-stage single-phase Grid-Connected (GC) Photo-Voltaic (PV) system. This PV system includes a DC-DC Positive Output Super Lift Luo Converter (POSLLC) and a single-phase inverter connected to a grid through an RL filter. Due to its advantages, the POSLLC was used between PV panel and inverter instead of the conventional boost converter. The state space equations of the system were solved. By using two Sliding Mode Controls (SMCs), PV panel voltage and POSLLC inductor current were controlled and the designed controls were compared. Two of these SMCs included a simple Sign Function Control (SFC) and a conventional SMC. To control the power injected into the grid with a unity power factor, an SMC was used. Perturb and Observe (P&O) method was employed to reach maximum power of the PV panel. The Maximum Power Point Tracking (MPPT) control generated the voltage reference of the PV panel. Similar controls were used for the boost converter instead of POSLLC. The obtained results were compared.
Hossein Ghadamian; Hassan Ali Ozgoli; Mojtaba Baghban Yousefkhani; Foad Farhani
Abstract
Regenerative Fuel Cell (RFC) systems are used for the enhancement of sustainable energy aspect in conventional fuel cells. In this study, a photovoltaic-electrolyzer-fuel cell integrated cycle has been presented. The proposed system has been designed as a novel approach for alleviating the ...
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Regenerative Fuel Cell (RFC) systems are used for the enhancement of sustainable energy aspect in conventional fuel cells. In this study, a photovoltaic-electrolyzer-fuel cell integrated cycle has been presented. The proposed system has been designed as a novel approach for alleviating the restrictions on energy streams in the RFC systems. Modeling of the system has been performed from the mass and energy point of view, based on both theoretical and practical procedures. To generate electricity from hydrogen, a proton exchange membrane fuel cell, integrated with an electrolyzer system which works by solar energy, has been used. Optimized results of required photovoltaic area have shown significantdifferences between theoretical and practical approaches. Moreover, all efficiencies of two scenarios including total efficiency have been indicated and analyzed. The main advantage of this system in comparison with single solar systems, is generation of internal energy of about 2.3 kW for producing 1 kW electricity by the fuel cell.
Abdolreza Esmaeli
Abstract
a new intelligent photovoltaic (PV) panel structure to extract the maximum power in mismatch irradiance is proposed. In conventional structures, difference of irradiance between series panels can cause the deviation of maximum power point. In this condition tracking MPP becomes difficult and reduces ...
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a new intelligent photovoltaic (PV) panel structure to extract the maximum power in mismatch irradiance is proposed. In conventional structures, difference of irradiance between series panels can cause the deviation of maximum power point. In this condition tracking MPP becomes difficult and reduces efficiency. Improvements in power electronics and its effects in PV industrial technology, developed many new PV structure in recent years. This paper proposes a new intelligent structure with module integrated converter for increasing energy capture in the PV series string. The advantage of new structure is that the MPP region extends from single panel MPP to a much wider range, causing the panels to operate independent of each other in mismatch condition. To study and show advantage of intelligent structure, a real simple model is selected and verified. For operating in MPP region, P&O algorithm is selected. Despite conventional structures, voltage is not appropriately varied for P&O algorithm used in intelligent structure and system experiences instability. To solve this instability problem, resistance is proposed as variable.MATLAB/Simulink is used for simulation and demonstration of expression. The results of this work have shown that using intelligent structure improves the energy harvesting up to 14 percent, and resistance is the best variable in tracking speed and accuracy.
