Wind Energy
M. A. Javadi; H. Ghomashi; M. Taherinezhad; M. Nazarahari; R. Ghasemiasl
Abstract
AbstractOptimal arrangement of turbines in wind farms is very important to achieve maximum energy at the lowest cost. In the present study, the use of Vestas V-47 wind turbine and uniform one-way wind in achieving the optimal arrangement of horizontal axis turbines in Manjil with genetic and Monte Carlo ...
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AbstractOptimal arrangement of turbines in wind farms is very important to achieve maximum energy at the lowest cost. In the present study, the use of Vestas V-47 wind turbine and uniform one-way wind in achieving the optimal arrangement of horizontal axis turbines in Manjil with genetic and Monte Carlo algorithms has been investigated. Jensen model is used to simulate the wake effect on the downstream turbines. The objective function is considered as the ratio of cost to power of the power plant. The results show that the Monte Carlo method compared with genetic algorithm will give a better result. Under the same conditions, the Monte Carlo algorithm will give 29% and 40% better results in terms of the number of turbines and output power, respectively. In terms of optimization, in the Monte Carlo algorithm, its fitness value is 16% less than the genetic algorithm, which indicates its better optimization.
Photovoltaic Systems
Pankaj Verma; Bharat Gangal; Gaurav Jain; Ravi Hada
Abstract
Most of the partial shading maximum power point tracking methods have been designed for the static shading pattern of the partial shading conditions, however, the irradiance pattern may change further when in partial shading mode. Therefore, to cover this research gap, a global maximum power point control ...
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Most of the partial shading maximum power point tracking methods have been designed for the static shading pattern of the partial shading conditions, however, the irradiance pattern may change further when in partial shading mode. Therefore, to cover this research gap, a global maximum power point control under varying irradiance (GCVI) algorithm is proposed in this paper. The algorithm does not use any sensors to detect the change in the irradiance, instead, the change in the current values of the modules are continuously monitored to detect the change. The reference voltages across which the peaks on the power curve are scanned are obtained from the reference voltage generation process, the consideration of these reference points avoids the excessive power losses in the system. The verification of the working of the proposed algorithm is carried out by simulating the photovoltaic system model on SIMULINK in MATLAB software. Simulations are carried out in various scenarios to show the effectiveness of the control. The simulation results illustrate that with the change in the global maximum under partial shading, the system successfully retunes to the new maximum point; the maximum point retunes from 10 kW to 9.2 kW and from 13.8 kW to 11.5 kW for two different case scenarios. Further, the comparisons are also carried out with the previously reported methods.
Transformation of Generated Electricity by Renewable Energies to Grid
M. Mahmoudian; S. Sadi; J. Gholami; Alirza Karimi
Abstract
This paper is dealt with energy hub systems in order to evaluate the sensitivity analysis of output power carriers in terms of input electricity and natural gas. Unlike the recent works which were solitary concentrated at operational cost minimization, in this research not only the energy carriers of ...
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This paper is dealt with energy hub systems in order to evaluate the sensitivity analysis of output power carriers in terms of input electricity and natural gas. Unlike the recent works which were solitary concentrated at operational cost minimization, in this research not only the energy carriers of proposed hub are being modeled, but also the sensitivity analysis of each power supplier are investigated. Since some of input power carriers in the hub, are decreased slightly or immediately according to unsolicited situations, the output electrical or thermal profile may not be supplied completely. Therefore the network operator must make a proper decision to utilize the best carriers not to reduce the system efficiency if possible. In this regard, the objective function including the energy costs for electrical, thermal and cooling demand carriers is optimized and the best solution will be extracted based on conditional value at risk (CAVR) of electricity market actors, using GAMS/CPLEX software, results in the higher the risk the network operator takes, the higher the profit from futures contracts. In the next step, the electricity price is predicted using ARIMA approach for the next four weeks and the sensitivity analysis for the future of the energy hub will be examined. The simulation results and changes in the share of energy carriers show that the importance of passive defense must be considered in the planning for energy supply of office buildings and the percentage of unsupplied energy must be studied.
Biomass Energy Sources
Madhurjya Saikia; Pranjal Sarmah; Partha P Borthakur
Abstract
Biodiesel, derived from biomass, offers significant environmental advantages by reducing CO2 and CO emissions and promoting energy self-sufficiency. Currently, biodiesel remains limited to DG sets used by a small number of farmers in India, with minimal adoption in the transportation sector. Numerous ...
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Biodiesel, derived from biomass, offers significant environmental advantages by reducing CO2 and CO emissions and promoting energy self-sufficiency. Currently, biodiesel remains limited to DG sets used by a small number of farmers in India, with minimal adoption in the transportation sector. Numerous challenges impede biodiesel's acceptance. This research focuses on identifying challenges connected to India's biofuel policy, supply chain inefficiencies, and vehicle technology. In terms of cultivation, land management, and the delivery of high yielding varieties to farmers, biofuel policies have failed to encourage indigenous feedstock. Instead, the Biofuel Policy 2022 encourages the imported palm oil sterain. Inconsistencies in the supply chain caused by policies impair the cost effectiveness of biodiesel. Diesel engines in automobiles have compatibility concerns owing to corrosiveness and high fuel consumption due to the fuel's low calorific value. Furthermore, biodiesel causes substantial NOx emissions. This study offers policy-level solutions, such as encouraging the production of domestic feedstocks through efficient management of wastelands. In this approach, farmers may receive high yielding seeds at a reduced cost until the industry is self-sufficient. In addition, Policy Linked Incentive (PLI) scheme can be given to biodiesel producers. A policy like ethanol blending can also be implemented. The biodiesel supply chain, like that of Germany, the United States, Malaysia, and Indonesia, must be optimized. For the technological challenges in diesel engines, the government must use policy intervention, to incorporate engine components suitable for biodiesel, as well as upgrade diesel engines by calibrating electronic control units and with exhaust gas recirculation systems.
M. Afshari; Seyed M. Mahdi Moosavi; M. B. Abadi; S.M.A. Cruz
Abstract
Doubly-fed induction generators (DFIG) have been widely used in wind turbines installed in the last decades. These generators are prone to some faults that could deteriorate their performance and even lead to their outage from the network. Stator inter-turn short-circuits (SITSC) and high resistance ...
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Doubly-fed induction generators (DFIG) have been widely used in wind turbines installed in the last decades. These generators are prone to some faults that could deteriorate their performance and even lead to their outage from the network. Stator inter-turn short-circuits (SITSC) and high resistance connections (HRC) in the stator are two major types of faults that cause electrical asymmetry in the stator circuit. Yet, SITSC are more noticeable and require immediate scrutiny. Hence, if an HRC can be distinguished from a SITSC fault, the immediate outage of the WT can be avoided in the case of an HRC. In this paper, both types of faults are studied and compared, being their detection performed using appropriate fault indices obtained from the stator current, rotor current, and rotor modulating voltage signals, all available in the control system of the DFIG. Several fault severity indices are proposed for a better evaluation of the fault extension, and the discrimination between SITSC and HRC is discussed. The performance of the defined fault indices is verified using a magnetic equivalent circuit model of the DFIG and an experimental setup with the DFIG running at several operating conditions.
E. Akbari; Abdul R. Sheikholeslami; F. Zishan
Abstract
Due to the lack of transmission and distribution network in remote and impassable areas due to the high cost of construction of the transmission line along with the unsuitable geographical conditions and taking into account the factors affecting sustainable energy production, the use of a hybrid system ...
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Due to the lack of transmission and distribution network in remote and impassable areas due to the high cost of construction of the transmission line along with the unsuitable geographical conditions and taking into account the factors affecting sustainable energy production, the use of a hybrid system seems like a sensible solution. Designing hybrid systems in order to respond throughout the year is of paramount importance. In this research, this study investigates the participation of wind turbine, photovoltaic and hybrid system with demand response in the presence of energy storage. The participation of renewable energy in providing demand response will be presented in three seminars: 1: The role of wind turbine partnership with storage, 2: the role of photovoltaic with storage, 3: hybrid mode with storage. The best ways to generate electricity are sought from three different scenarios to select the best possible case. It can be said that renewable energy is economically competitive with fossil energy and this energy can be used and implemented along with distribution networks. While analyzing the participation of different hybrid systems and estimating the cost of optimization, the total price for each unit of energy production, energy storage, Net Present Cost (NPC) and participation in demand supply will be compared. Comparative results show that the hybrid design can have a more appropriate and desirable performance. HOMER software is used to determine the optimal possible modes for these systems, in the position of 37 degrees latitude and 42 degrees longitude.
Photovoltaic Systems
H. Eshghi; M. Kahani; M. Zamen
Abstract
The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their ...
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The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their lifetime. To solve this problem, various methods have been provided for cooling the panels. One of these methods is the application of heat pipes. In this research, a PV panel equipped with thermosyphon heat pipe is introduced. The thermosyphon was connected to the back sheet of the panel to enhance the cooling effect of the PV system. Instead of using polyvinyl fluoride polymer, unlike conventional panels, an aluminum plate was used to connect the heat pipe to the back of the panel to have better cooling. In addition, to increase the heat transfer area between heat pipe and back surface of the panel, a special groove was drilled on the aluminum plate. Three different filling ratios (25, 45 and 65%) of distilled water as the working fluid were used in thermosyphon. The best performance of the systems was obtained at 45% of filling ratio, in which, the electrical power of the PV panel equipped with heat pipe was around 3.2% better than the conventional PV panel. In this case, 6.8 °C temperature difference was observed in the water tank connected to the condenser section of heat pipe which means that 54 kJ heat was transferred to the water in the tank.
Applications of Machine Learning Algorithms in Renewable Energies
Kossoko Babatoundé Audace Didavi; Richard Gilles Agbokpanzo; Bienvenu Macaire Agbomahena
Abstract
In this work, the photovoltaic power forecast for the next 24 hours by combining a time series forecasting model (LSTM) and a regression model (XGBoost) from direct irradiation only is performed. Several meteorological parameters such as irradiance, ambient temperature, wind speed, relative humidity, ...
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In this work, the photovoltaic power forecast for the next 24 hours by combining a time series forecasting model (LSTM) and a regression model (XGBoost) from direct irradiation only is performed. Several meteorological parameters such as irradiance, ambient temperature, wind speed, relative humidity, sun position, dew point were identified as influencing parameters of PV power variability. Thanks to the parameter extraction and selection techniques of the XGBoost model, only the direct irradiation could be kept as input parameters. The LSTM model was used to predict the direct irradiation for the next 24 hours and the XGBoost model to estimate the future power from the predicted irradiation. These models were developed under Python 3, the exploited data were downloaded in the PVGIS database for the city of Abomey-Calavi in Benin and the prediction was carried out on a panel of 1000W of peak power. An experimental validation was then performed by comparing the predicted irradiance values to the measured values on site. It was obtained for the LSTM model a root mean square error of 3.66 W/m2 and for the XGBoost model a root mean square error and a regression coefficient of 1.72 W and 0.992129 respectively. These results were compared to the LSTM-XGBoost performances with irradiation, temperature, sun position and wind speed as inputs. It was found that the use of irradiation alone as input did not as such impair the forecast performance. The proposed method was also found to be more efficient than LSTM and CNN models used alone.
Ali Fakour; Soheila Bi-Ria; Azar Rahimifar
Abstract
countries need to use energy resources to achieve economic growth, but due to the limitation of fossil energy resources such as oil and coal, the increase in the price of these resources in recent years, as well as the resulting environmental pollution, the countries concerned The use of clean and renewable ...
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countries need to use energy resources to achieve economic growth, but due to the limitation of fossil energy resources such as oil and coal, the increase in the price of these resources in recent years, as well as the resulting environmental pollution, the countries concerned The use of clean and renewable energy sources has increased. Considering the importance of using renewable energy for the sustainable economic growth of the country in the coming years and the novelty of this topic in domestic studies, therefore, in this research, the impact of renewable energy consumption on the growth of Iran's GDP has been investigated.The innovation of this research compared to previous studies is the use of influential variables such as fixed capital formation, employment rate, trade openness and sanctions in addition to the variable of renewable energy consumption on the country's economic growth. In fact, in this study, the investigated model has been expanded with effective variables according to Iran's economy, which has not been addressed in previous studies. We considered time series for variables including renewable energy consumption, GDP per capita, capital formation, employment rate, trade openness, and sanctions for the time period 2010–2020. In this research, the vector autoregression model with distributed intervals (ARDL) has been used to estimate the relationship between variables. The results show that there is a positive and significant relationship between renewable energy consumption, fixed capital formation, employment rate, trade openness and GDP growth, and sanctions have had a negative and significant impact on GDP growth.
Fuel Cells
M. Rostami; A.H. Farajollahi; M. Marefati; R. Fili; F. Bagherpor
Abstract
The propulsion system of an Unmanned Aerial Vehicle (UAV) plays an essential role in its performance, stability and flight endurance. In this study, two types of propulsion systems for UAV (differentiated based on fuel type) are studied to determine their characteristics and advantages. These proposed ...
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The propulsion system of an Unmanned Aerial Vehicle (UAV) plays an essential role in its performance, stability and flight endurance. In this study, two types of propulsion systems for UAV (differentiated based on fuel type) are studied to determine their characteristics and advantages. These proposed propulsion systems are using a solid oxide fuel cell (SOFC) to generate the heat required for the operation of the turbine and generating thrust. To achieve the best operating condition, a multi-objective Non-Dominated Sorting Genetic Algorithm (NSGA-II) in MATLAB is used to decide key design parameters. For reaching the best conditions where the acceptable thrust is accompanied by reasonable flight duration, the TOPSIS decision-making method was considered. Results indicated that the efficiency and generated power of the propulsion system will increase by higher flight altitude or compressor pressure ratio. Also, due to the recirculation of fuel in the SOFC’s anode, the higher efficiency is observed in comparison when hydrogen is used; since anode-recirculation causes higher fuel utilization. The optimization result shows that the efficiency and fuel consumption for the hydrogen-fueled system is 48.7% and 0.0024g/s, respectively, and 67.9% and 0.0066kg/s for methane-fueled engine. It was also found that, maximum efficiency for both hydrogen- and methane-fueled systems are available with the stack temperature of 1025 K; however maximum thrust for these systems is at the stack temperature of 1075 K. In addition, increasing fuel rate of the SOFC power unit helps the process of generating extra power and thrust for UAVs.
A. Abazari; M.M. Aziminia
Abstract
Flap-type wave energy converter is one of the oscillating surge devices for generating electricity from the ocean wave source. It comprises a vertical plate pivoted on a hinged base that oscillates rotationally due to the exciting wave. Splitting a single flap into two separated flaps in a double arrangement ...
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Flap-type wave energy converter is one of the oscillating surge devices for generating electricity from the ocean wave source. It comprises a vertical plate pivoted on a hinged base that oscillates rotationally due to the exciting wave. Splitting a single flap into two separated flaps in a double arrangement may cause different dynamic characteristics. This can improve the output extracted power versus the excitation period. Therefore, this effect is investigated in the present study through a dynamic mathematical model. The hydrodynamic coefficients and exciting torques in the equation are calculated based on the Boundary Element-based software of ANSYS AQWA. In the next step, the rotational displacement is calculated through the frequency domain approach based on the assumption of the regular monochromatic and head-on waves, and consequently, the maximum power is computed regarding the optimum power take-off damping strategy. Finally, in the same procedure as the single flap, the output power for the double arrangement is derived. The results show that decreasing the natural period for each flap can potentially cause a wideband response of the total power for the double configuration compared to the single one.
Energy Policy
Moslem Akbari Vakilabadi; Sadegh Nikbakht Naserabad; Alireza Binesh
Abstract
In this paper, it is determined exactly how much of the loss of exergy in a specify component is concerning the own component and how much of the exergy loss is due to the effects of the rest of the components on that component. In this new method of exergy analysis, at first, the exergy loss in a component ...
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In this paper, it is determined exactly how much of the loss of exergy in a specify component is concerning the own component and how much of the exergy loss is due to the effects of the rest of the components on that component. In this new method of exergy analysis, at first, the exergy loss in a component is classified as avoid. /unavoid categories. With this classification, it is possible to understand what quantity of the exergy loss of a component is eliminated by optimizing that component and how much of the exergy dissipation can never be eliminated and is related to the nature of the component. In the next classification, by categorizing the exergy loss into endo./exo., we can find out how much of the exergy destruction is due to the non-optimality of other components and has nothing to do with the component itself. Finally, the categories are divided into avoid-endo, unavoid-endo, avoid-exo and avoid-enxo. By performing this new method, the results demonstrate that the highest exergy destruction (1.976 MW) happens in the evaporator, 68% of which is unavoid-endo. exergy loss. The highest avoid. exergy loss relates to low pressure turbine (0.5791 MW). It is shown that optimizing of surrounding components of deaerator, economizers, and evaporators has a greater effect on decreasing the exergy dissipation of these own components, and the most Avoid. exergy destruction is in heat exchangers, pumps, condensers, turbines, expansion valves, reheaters, and superheaters.
M.R. Amirrud; M. Shahin
Abstract
Wind energy is considered as a precious replacement for fossil fuels in electricity generation. In this regard, many governments (e.g. Iran) tend to support development of this type of renewable energy source. However, fluctuations in Iran’s economic conditions and uncertainty in available wind ...
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Wind energy is considered as a precious replacement for fossil fuels in electricity generation. In this regard, many governments (e.g. Iran) tend to support development of this type of renewable energy source. However, fluctuations in Iran’s economic conditions and uncertainty in available wind power increase the risk of investment. In this investigation a methodology is used to address the uncertainty in wind conditions using probability of occurrence of minimum wind speed. In addition, a feasibility study is considered for economic assessment of establishing a wind turbine power plant in Kerman province, Iran. A sensitivity analysis is developed to analyze the effect of changes in inflation and currency rates on the project economic viability. Results show that the proposed site enjoys excellent wind power potential with respect to wind power density of 971.4 W/m2 at 100 meters height. Economic analysis indicates that the project is viable when its budget is supplied through governmental resources (providing US dollar at governmental rate). However, sensitivity analysis reveals that the project is no longer viable when its budget is supplied through foreign exchange market (providing US dollar at market currency rate). Therefore, this paper suggests that if government tends to support development of wind energy in Iran, it is necessary to either provide the project budget by governmental resources (4200 T/$) or buy electricity higher than 1391.6 T/kWh (845.6 T/kWh more than current feed-in-tariff). Furthermore, nonlinear relationship between net present value (NPV) and inflation shows that reduction in inflation can significantly improve the investment payoff.
Amin Baghani
Abstract
In recent years, the growing demand for energy and environmental requirements has focused much attention on solar energy as a renewable source. The building rooftops are the most suitable places for installing photovoltaic panels in urban and rural areas. In large districts, accurate estimation of radiation ...
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In recent years, the growing demand for energy and environmental requirements has focused much attention on solar energy as a renewable source. The building rooftops are the most suitable places for installing photovoltaic panels in urban and rural areas. In large districts, accurate estimation of radiation received by the rooftops requires the existence of detailed 3D information about them. This research aims to provide an efficient method to estimate solar energy production potential from the rooftops using the UAV photogrammetry method and GIS. The proposed method considers both the factors of the geometric features of the rooftops (slope and azimuth) and the shadow of the adjacent features. A threshold for minimum separated suitable rooftops for installing photovoltaic panels received radiation and rooftop area. Converting received radiation into electrical energy was made based on the average level of current world technology for solar panels. Providing a comparison between the amount of electricity produced during the four seasons and throughout the year as an effective parameter related to the consumption pattern is another achievement of this research. The findings of this research can be used in various fields, such as electricity and the construction industry, as well as macro planning, to benefit from clean energy. The results of implementing the proposed method for a rural area showed that out of a total of 543 existing roofs, 422 roofs are suitable for installing solar panels. Also, for these rooftops, the potential to produce 5741 MWh of electricity will be available in one year.
Transformation of Generated Electricity by Renewable Energies to Grid
A. Ghaedi; M. Mahmoudian; R. Sedaghati
Abstract
The widespread growing of electric vehicles (EVs) in distribution networks could be a variety of challenges and opportunities for the electricity network. This issue is important because the owners of electric vehicles are trying to maximize their profits, which in turn can cause many problems such as ...
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The widespread growing of electric vehicles (EVs) in distribution networks could be a variety of challenges and opportunities for the electricity network. This issue is important because the owners of electric vehicles are trying to maximize their profits, which in turn can cause many problems such as increased losses, congestion, increase network costs, etc. in distribution networks. Therefore, it is required to study different aspects of this new technology such as reliability and failure rate. For this purpose, the presented paper introduces a reliability model based on the Markov theory for different types of electric vehicles, and the main novelty is to determine the impact of the failure rate of the composed components of the each electric vehicle on the overall failure of the vehicle. In the proposed reliability models for these electric vehicles, the failure of the main composed components is considered. To compare different types of electric vehicles from reliability point of view, numerical results associated with the reliability evaluation of these vehicles are given. It is deduced from the numerical results associated to the reliability evaluation of different types of electric vehicles that the reliability of the compound plug-in hybrid electric vehicle is more than the other technologies.
S.E. Kashfi; A. Ebrahimi; S. Kazemi
Abstract
Compliant offshore tension leg platforms (TLP) are adaptive platforms with a vertical mooring system. These types of platforms are usually used in deep water. Adding sufficient initial tension to the mooring, the vertical movements of the structure will be reduced. Tendons, body, and deck are different ...
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Compliant offshore tension leg platforms (TLP) are adaptive platforms with a vertical mooring system. These types of platforms are usually used in deep water. Adding sufficient initial tension to the mooring, the vertical movements of the structure will be reduced. Tendons, body, and deck are different components of this platform, with the body being the most important in terms of hydrodynamic forces, weight, and cost. In this study, an investigation is done on a TLP with a wind turbine by numerical analysis. The boundary element and the finite volume method were carried out in this work in the Caspian Sea. Then the platform was analyzed at a depth of 150 meters, under the influence of wind, current, and irregular waves with one and 100-year return period, and at a zero-degree wave angle. The results of the two numerical approaches are very close and almost identical. The tension leg platform was stable in the different irregular waves. Also, the response amplitude operator calculated using two numerical methods has a good agreement.
Desalinations Systems with Renewable Energies
Neda Mehtari; Mostafa Kahani; Mohammad Zamen
Abstract
The current research focuses on the utilization of three waste water streams from a power plant located in southwestern Iran for desalination purposes and to prevent the waste of heat from the boiler blowdown stream while reducing carbon dioxide emissions by preheating the cooling water. Three different ...
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The current research focuses on the utilization of three waste water streams from a power plant located in southwestern Iran for desalination purposes and to prevent the waste of heat from the boiler blowdown stream while reducing carbon dioxide emissions by preheating the cooling water. Three different scenarios are simulated using the Thermoflow-GT master 23 software, considering the conditions of power plant. The optimal values for the top brine temperature (TBT) of cooling water and the mass flow rate of the hot steam are selected by sensitivity analysis. The premier scenario consists of eight stages, with five stages dedicated to heat recovery (HGS) and three stages for heat rejection section (HRS). The optimal value for the TBT of cooling water is determined to be 90℃, the produced freshwater capacity in the desalination unit is found to be 1.69 kg/s, and the gain output ratio (GOR) of the system is about 3.60. The proposed unit requires 0.47 and 10.15 kg/s of hot steam and cooling water, respectively and the overall heat transfer coefficient is 2069.2 W/m2 ℃. In addition, the feasibility of utilizing a solar farm to generate the necessary thermal energy for the system is being evaluated.
Energy Policy
M. Shiri Dezaki; Z. Zandian Sefiddashti; M. Jahangiri; A. Haghani; A. Tahmasebi
Abstract
The outbreak of Coronavirus disease (COVID-19) in late 2019 and its eventual transformation into a global pandemic caused a shock wave across countries. The renewable energy (RE) sector, which has always been one of the leading areas for promoting environmental sustainability, has not been spared from ...
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The outbreak of Coronavirus disease (COVID-19) in late 2019 and its eventual transformation into a global pandemic caused a shock wave across countries. The renewable energy (RE) sector, which has always been one of the leading areas for promoting environmental sustainability, has not been spared from the epidemic. The integration of the effects of the epidemic on the global economy and the fluctuation of oil prices due to global quarantines around the world increased the impact of this disease on the RE industry. Although the COVID-19 crisis has had a negative effect on efforts to develop RE, analysts believe that in the future, more of the world's energy needs will come from RE sources. The International Energy Agency (IEA) has claimed that RE consumption is likely to increase because people tend to have clean and sustainable energy sources such as wind, water, and solar energy more than before. In the present work, the effects of the COVID-19 outbreak on environmental changes, energy consumption, the need to use RE, investments made in the field of RE, and the well-being of the people of the world are examined and details and results will be discussed. The main aim of the present work is to review the studies of researchers on the impact of COVID-19 disease on the environment and RE.
A. Zare; M. Simab; M. Nafar
Abstract
Due to the growing demand in the electricity sector and the shift to the operation of renewable sources, the use of solar arrays has been at the forefront of consumers' interests. In the meantime, since the production capacity of each solar cell is limited, in order to increase the production capacity ...
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Due to the growing demand in the electricity sector and the shift to the operation of renewable sources, the use of solar arrays has been at the forefront of consumers' interests. In the meantime, since the production capacity of each solar cell is limited, in order to increase the production capacity of photovoltaic (PV) arrays, several cells are arranged in parallel or in series to form a panel in order to obtain the expected power. Short circuit (SC) and open circuit (OC) faults in the solar PV systems are the main factors that reduce the amount of solar power generation, which has different types. Partial shadow, cable rot, un-achieved maximum power point tracking (MPPT) and ground faults are some of these malfunctions that should be detected and located as soon as possible. Therefore, effective fault detection strategy is very essential to maintain the proper performance of PV systems to minimize network interruptions. The detection method must also be able to detect, locate and differentiate between SC and OC modules in irradiated PV arrays and non-uniform temperature distributions. In this paper, based on artificial intelligence (AI) and neural networks (NN), neutrons can be utilized, as they have been trained in machine learning process, to detect various types of faults in PV networks. The proposed technique is faster than other artificial neural networks (ANN) methods, since it uses an additional hidden layer that can also increase processing accuracy. The output results prove the superiority of this claim.
Biomass Energy Sources
Mohammad Khoobbakht; Mohsen Soleymani; Kamran Kheiralipour; Mahmoud Karimi
Abstract
The effect of biodiesel percentage in biodiesel-diesel blends on the engine under different engine operation conditions must be predicted to achieve high performance. The goal of the present paper was to model brake power, brake torque, thermal efficiency, and specific fuel consumption of a diesel engine ...
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The effect of biodiesel percentage in biodiesel-diesel blends on the engine under different engine operation conditions must be predicted to achieve high performance. The goal of the present paper was to model brake power, brake torque, thermal efficiency, and specific fuel consumption of a diesel engine fueled by algal biodiesel-diesel blends. The response surface methodology was successfully applied to model the performance indicators of biodiesel-diesel fueled OM 314 diesel engine at various engine loads and rotational speeds. Brake power, torque, and thermal efficiency increased by increasing engine load. Increasing engine rotational speed caused increase in brake power whereas highest brake torque and thermal efficiency was obtained in medium engine rotational speed. Increase of biodiesel percentage caused decrease in. Biodiesel had negative effects, but it had lower effects than engine load and rotational speed on the change of the engine performance indicators. Brake specific fuel consumption decreased by increasing load but it was lowest in medium rotational speeds. A quadratic model was suitably fitted to predict the effects of input-output variables with statistical significance of 1% probability level. The coefficient of determinations for prediction of the engine brake power, brake torque, thermal efficiency, and brake specific fuel consumption were 97.63, 99.74, 97.41, and 95.72%, respectively. The result of the present work is useful to find optimum biodiesel percentage and engine load and rotational speed to achieve high performance fuel blends.
Solar Thermal Engineering
Mahdi Rezaei Rad; Rouzbeh Shafaghat; Amirhossein Aghajani afghan; Behrad Alizadeh Kharkeshi
Abstract
This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north ...
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This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north of Iran (Mazandaran province, Babol), and the effect of the inlet air's temperature and flow rate on the system's functional characteristics and condenser was investigated to improve the performance. Sensors measured the data related to the fluid temperature and humidity of the cycle at different points; other data was also gathered by psychrometric chart and EES software. The results section investigates water generation rate, GOR, coefficient of performance (COP), and condenser efficiency. The results showed that the highest water production is 420 g/hr, and the highest GOR is 0.19. Also, the water production rate and COP increase as the inlet air temperature rises. At temperatures lower than 75o Celsius, due to the air saturation, the maximum point of the water production and COP occurs at a flow rate of 0.022 kg/s. at high temperatures, increasing the flow rate raises water production, and on the other hand, the COP in the condenser is 0.8 at the highest point. According to the economic analysis done for the proposed model, the freshwater cost is 0.098-0.049 $/year for one liter.
Mojtaba Ghiyasi
Abstract
Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse ...
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Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse DEA approach as a valuable method for the future planning of the IWPPs. In this step, we considered five different scenarios from a short-run up to a long-run planning for electricity production by renewable energy. In the short-run we just need more capacity factor rather than capital. Although in the mid-run we did not presume capital extension, the result suggested this. In the end, in the long-run planning extension in not only capacity factor but also more investment in the higher technologies is a requirement for reaching the desired electricity production.
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 ...
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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.
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 ...
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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.
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 ...
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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%.