Biomass Energy Sources
Praveen Kumar G Yadav; Din Bandhu; Jayasimha K. Reddy; Meenakshi R. Reddy; Chadaram Srinivasu; Ganesh Babu Katam
Abstract
Recycling plastics into energy sources is the most promising method for cutting down on pollution and trash. In this regard, predictions of adiabatic engines using pistons with thermal barrier coatings (TBCs) were made to reduce in-cylinder heat rejection, safeguard the underlying metallic surfaces from ...
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Recycling plastics into energy sources is the most promising method for cutting down on pollution and trash. In this regard, predictions of adiabatic engines using pistons with thermal barrier coatings (TBCs) were made to reduce in-cylinder heat rejection, safeguard the underlying metallic surfaces from thermal cracking, and indeed reduce engine emissions. This study compares the predicted thermal and physical parameters of Plastic Waste Oil (WP) with its diesel blends in fixed proportions of WP10D90 (10% plastic oil, 90% diesel), WP20D80, WP30D70, WP40D60, and WP50D50 to diesel values. The study further explores the concept of the utility function to evaluate the best-ranked fuel blend in each category of various performance characteristics namely BTE, BSFC, UHC, CO, and NOx. Additionally, the effect of the thermal barrier piston coating on CI engine performance metrics and emissions was studied and compared to those achieved with regular diesel oil. When compared to diesel, the results state that the WP40D60 blend has the highest brake thermal efficiency, i.e., 31.62% at 80% load, and the lowest NOx emissions at all load conditions. In addition, it was further observed that the WP20D80 has lower hydrocarbon (HC) emissions at 20% load and an increment in CO emissions for all blends and load combinations. Overall, WP30D70 has come up with the best fuel as per the Utility function.
Low-carbon Technologies
F. Shateri Aliabad; Y. Ebazadeh; R. Alayi; I. Suwarno; A. Najafi; S. Ollah Mohammadi-Aylar
Abstract
In this research, technical and economic analysis of the use of storage devices in the hybrid system of wind and solar is performed with the aim of providing a maximum electrical load of residential buildings. To this aim, two scenarios of grid-connected and off-grid system have been studied. two parameters ...
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In this research, technical and economic analysis of the use of storage devices in the hybrid system of wind and solar is performed with the aim of providing a maximum electrical load of residential buildings. To this aim, two scenarios of grid-connected and off-grid system have been studied. two parameters of high reliability and cost per production capacity were used. According to these two parameters, due to the low cost of grid energy and the high cost of purchasing the second scenario cell was selected with the grid-connected system approach. Based on this system, the final generation that has a surplus of production sells the energy to the network and uses the network to supply the load when there is a lack of power to supply the load. According to the cases mentioned in the second scenario, more than 50% of the requested load is supplied by the photovoltaic cell, which indicates the high potential of the study area. For the selected system, the return on investment was 7.53 years, considering the cost of energy is 0.13 $/kWh
Biomass Energy Sources
Ganesh S Warkhade; Ganesh Babu Katam; Veeresh Babu Alur
Abstract
This paper analyses the VCR (variable compression ratio) engine's performance, combustion, and emission output responses. The experimental results were modelled using the Grey Taguchi method (GTM) for input parameters of compression ratio, load, and fuel blends. The objective is to find the optimal combination ...
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This paper analyses the VCR (variable compression ratio) engine's performance, combustion, and emission output responses. The experimental results were modelled using the Grey Taguchi method (GTM) for input parameters of compression ratio, load, and fuel blends. The objective is to find the optimal combination of input parameters in the minimum number of experiments for minimum emission, better performance, and combustion parameters. The Taguchi’s L9 orthogonal array with GTM is used to get the optimum combination of input parameters. The Taguchi was used to analyze the S/N ratio of experimental data and the gray-based method for optimization of multi-objective to single-objective optimization by assigning the suitable weighting factor to each response. The S/N ratio analysis of grey relational grade (GRG) shows the fuel B10, CR 16, and load at 100% of the optimal input factor level. This optimal level is further confirmed by the TOPSIS method. The analysis of variance (ANOVA) for input to GRG shows the highest influencing factor is the load with a 52.82% contribution, followed by CR at 28.38%, and fuel at 10.52%. The confirmatory results show an improvement of 56.1%. The novelty of this experimentation was to study feasibility of existing engine for alternative fuel with slight modification. At above optimal conditions, this biodiesel can be used efficiently in an unmodified compression ignition engine.
A. R. Bozorgi
Abstract
Noise pollution is known as the biggest environmental problem of horizontal axis wind turbines. The main part of the noise is in the range of Low Frequency Noise (LFN) since wind turbines rotate slowly. Several studies show that the LFN could have adverse effects on human health. In this study, the LFN ...
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Noise pollution is known as the biggest environmental problem of horizontal axis wind turbines. The main part of the noise is in the range of Low Frequency Noise (LFN) since wind turbines rotate slowly. Several studies show that the LFN could have adverse effects on human health. In this study, the LFN generated by NREL VI wind turbine in wind speeds of 13 m/s is calculated by using a hybrid approach. In this approach, noise sources are defined on a data surface (DS), and then the noise propagating form the DS is calculated. The results show that a DS obtained by scaling the blade span with a size factor of 5 is appropriate for surrounding all main sources in this problem. It means, in addition to sources located on blade surface, a significant part of steady sources generating LFN is far from blades. On the other hand, the results show that tip vortices have no significant effect on the LFN.
M. Khatibi; A. Rabiee
Abstract
Electricity generation through renewable energy sources such as wind energy has been growing in recent years due to several reasons including free and infinite resources as well as their considerable impact on the reduction of fossil fuels consumptions as well as CO2 emissions. This paper aims to assess ...
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Electricity generation through renewable energy sources such as wind energy has been growing in recent years due to several reasons including free and infinite resources as well as their considerable impact on the reduction of fossil fuels consumptions as well as CO2 emissions. This paper aims to assess the impact of grid-connected large-scale wind farms in a region located in Iran, on the reduction of natural gas as well as gasoil fuel consumptions in heat-cycle power plants and their related CO2 emissions as a practical case study. The wind farms under study comprise about 51% of the total grid connected capacity of wind power generation in Iran by the end of March 2021. The total energy yielded by the studied wind farms are first extracted over a two-year period from April 2019 to March 2021 based on a detailed practical data and then, its impact is investigated on the reduction of natural gas and gasoil consumptions in a real heat-cycle power plant due to its practical fuel intake data. Finally, the reduction of CO2 emission is calculated as the result of reduction in the natural gas and gasoil consumptions of the considered heat-cycle power plant. The results of this practical case study well demonstrate the effective role of wind farms energy yields on the reduction of fossil fuels consumption in heat-cycle power plants and thus, the significant reduction of CO2 emission as one of the most crucial aspects of decarbonization and fossil fuel phase out plans.
Energy Policy
M. Monfared; E. Hasani Alavy; M. Khanpoor Siahdarka; F. Rahnama
Abstract
In order to systematically reduce the risk of SARS-CoV-2 infection in indoor space, it’s important to understand the building design strategies and air quality enhancement methods that set to mitigate this threat. This paper aims to introduce the different HVAC technologies used to mitigate the ...
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In order to systematically reduce the risk of SARS-CoV-2 infection in indoor space, it’s important to understand the building design strategies and air quality enhancement methods that set to mitigate this threat. This paper aims to introduce the different HVAC technologies used to mitigate the spread of COVID-19 in university settings in particular. Many of these technologies came to be as an outcome of scientific interest in the enhancement of indoor environmental quality. Thus, it is important to understand where airborne pathogens fit in the overall scheme of Indoor Air Health. Similarly, this paper set to reimagine architectural methods as solutions to the problem of airborne transmission of diseases. Based on the urgency of the problem and the demand of the market this paper discusses a summary of applicable technologies and strategies to combat airborne viruses, particularly COVID-19, in ventilation systems and enclosed spaces. By presenting an overview of the problem and the solutions that integrate engineering controls, design strategies and, indoor air sanitization techniques aim to create healthier indoor environments this paper aspires to move the research forward.
Fuel Cells
Amarnath Gundalabhagavan; Veeresh Babu Alur; Ganesh Babu Katam; Kshitij Bhosale
Abstract
Fuel cells have been identified as a promising technology to meet future electric power requirements. Out of various fuel cells, Proton Exchange Membrane Fuel Cells (PEMFC) has been staged up as they can operate at low temperatures and also have high power density. In this article, the flow field design ...
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Fuel cells have been identified as a promising technology to meet future electric power requirements. Out of various fuel cells, Proton Exchange Membrane Fuel Cells (PEMFC) has been staged up as they can operate at low temperatures and also have high power density. In this article, the flow field design of a Single Serpentine Flow Field (SSFF) has been modified to L-Serpentine Flow Field (LSFF) in order to reduce thermal and water management problems in PEMFC. A numerical study was conducted on 441 mm2 active area at 700C and 3 atm operating conditions, to evaluate various flow characteristics by comparing LSFF with SSFF, and it was observed that temperature and species flux distribution in LSFF enhanced significantly. The modification of the flow field yielded remarkable improvements in various aspects. These enhancements included a more uniform distribution of membrane water content, an impressive 8% increase in O2 consumption, a remarkable 22% improvement in product evacuation demonstrated by the H2O species profile, attributed to a 40% reduction in product travel distance. Additionally, a noteworthy 10% increase in power density was achieved. Despite a slight increase in pressure drop due to the additional bends and turns in the modified flow field, the impact on power density remained insignificant. These findings highlight the immense potential of the modified flow field to significantly enhance performance.
R. Rostami; H. Hosseinnia
Abstract
Utilizing distributed generation (DG) units in power system has positive impacts such as: reduction active and reactive power loss, reduce load curtailment, increasing system reliability and reducing the need of installing the new power plant. Wind turbine (WT) is a type of DGs. Employing demand side ...
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Utilizing distributed generation (DG) units in power system has positive impacts such as: reduction active and reactive power loss, reduce load curtailment, increasing system reliability and reducing the need of installing the new power plant. Wind turbine (WT) is a type of DGs. Employing demand side management in a residential, industrial and commercial loads could highlight the role of consumers in managing the total power and increasing the efficiency of system. In this paper the impacts of utilizing WT in improving technical constraints of the reconfigurable distribution system has been evaluated. The Monte Carlo based power flow equation is implemented to the presented scheduling problem. Simulations are done on IEEE 33 bus reconfigurable distribution system
Sabastine C Ezike; Jamu B. Yerima; Dunama William; Babangida Alkali; Abubakar D Ahmed
Abstract
Dye-Sensitized solar cells (DSSCs) are among the family of third generation photovoltaic (PV). DSSCs are promising with the theoretical predicted value for power conversion efficiency (PCE) of 20%. In this paper, explicit equations for the single-diode equivalent circuit model parameters of a solar cell ...
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Dye-Sensitized solar cells (DSSCs) are among the family of third generation photovoltaic (PV). DSSCs are promising with the theoretical predicted value for power conversion efficiency (PCE) of 20%. In this paper, explicit equations for the single-diode equivalent circuit model parameters of a solar cell were modeled based on the characteristic points on the I-V curves that do not require the short-circuit and open-circuit slopes as input data. The equations were used to calculate the five model parameters (n, Rs, Rsh, Iph, Io) of a standard solar cell-based DSSCs composed of different natural photosensitizers. The results show that four(~28.5%) devices with natural photosensitizers (bitter gourd, sun flower, rose flower, tomato) manifest parameter irregularities i.e. they have negative series resistance or complex shunt resistance. Despite the occurrence of irregular parameters, there is still a good match between the calculated and measured photoelectric characteristics. This supports the idea that the nature of the parameter values does not matter provided there is a good match between measured and calculated I-V characteristics. The bitter gourd-based DSSC demonstrates the most promising photosensitizer for DSSC fabrication based on values of the parameters. Hence, the agreement of the calculated and measured parmeters suggests that modeling is good approach for extraction solar parameters.
H. Moradi; N. Piri Yengijeh; A. Hajizadeh
Abstract
The expansion of renewable energy sources (RESs (and advances in power electronics have been led to more attention being paid to DC microgrids (DCMGs). DCMGs enable the exploitation of all renewable energy potentials. Along with the advantages of RESs and DCMGs, the use of RESs is associated with the ...
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The expansion of renewable energy sources (RESs (and advances in power electronics have been led to more attention being paid to DC microgrids (DCMGs). DCMGs enable the exploitation of all renewable energy potentials. Along with the advantages of RESs and DCMGs, the use of RESs is associated with the challenges of absence or lack of inherent inertia. Inertia in the DCMGs plays an important role in reducing voltage changes under destructive events such as load change and power change. Therefore, by applying energy storage systems (ESSs) in DCMGs, and inertia emulation the mentioned challenges can be overcome. The proposed control scheme is implemented based on the concept of the virtual supercapacitor in the inner control loop of the ESS interface dual-half-bridge (DHB) converter with DCMG to emulate the inertia. Due to the high efficiency, electrical insulation, inherent soft switching, and the need for a smaller filter, the DHB converter has been used. Finally, a DCMG is simulated in MATLAB / Simulink. The simulation results show the efficiency and flexibility of the proposed scheme in terms of inertia emulation.
Electricity Generation by Green Energy Sources
H. Ashofteh; A. Behzadi Forough
Abstract
Energy is one of the most critical factors in economic development, but achieving sustainable development is impossible without environmental protection and improving economic conditions. If a country is dependent on energy, any structural reform policies to reduce energy consumption may reduce economic ...
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Energy is one of the most critical factors in economic development, but achieving sustainable development is impossible without environmental protection and improving economic conditions. If a country is dependent on energy, any structural reform policies to reduce energy consumption may reduce economic growth. Saving energy consumption and the development and application of alternative technologies, especially renewable energy, has a significant role in controlling and reducing the consumption of fossil energy carriers and, consequently, reducing the emission of environmental pollutants and achieving sustainable development. This article deals with the feasibility of constructing renewable energy power plants in Khoy city. First, using RETSCREEN software, the economic and environmental conditions of the construction of renewable energy power plants in Khoy city are examined. Using PVSYST software, the requirements for constructing solar power plants are discussed in a specialized way. In this article, the inflation rate is 12%, and the interest rate is 4%. The construction of solar and geothermal power plants in this city can be prioritized based on the results. The solar power plant has a production capacity of 30 MW. 212194 meters of land, and a capital of 40 million dollars are needed to construct this solar power plant. The payback period of this project in Khoy city is estimated at 25 years.
Shahrzad Talebsafa; Masoud Taheri Shahraeini; Xiaoshan Yang; Mohammadreza Rabiei
Abstract
Thermal comfort is one of the most important factors affecting the quality of outdoor space. This work investigates the effect of shade on outdoor thermal comfort during the hot season. For this purpose, meteorological measurement and questionnaire surveys are conducted simultaneously at four points ...
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Thermal comfort is one of the most important factors affecting the quality of outdoor space. This work investigates the effect of shade on outdoor thermal comfort during the hot season. For this purpose, meteorological measurement and questionnaire surveys are conducted simultaneously at four points of the university campus in the cold semi-arid climate of Shahrood, Iran. Then the ENVI-met V4 is validated and implemented to examine the impact of different shading scenarios on outdoor thermal comfort. The neutral physiological equivalent temperature (PET) and the upper boundary of the PET comfort range are obtained at 21.9 °C and 26.9 °C, respectively. The results demonstrate that the plant shade creates the most acceptable thermal environment. Also shading cause a significant reduction in the PET value and thermal stress, while increasing the comfort levels and the comfort hours during the sunny days. Furthermore, the simulation results indicate that creating shade in the open space by trees contribute to lower level of mean radiant temperature up to 24.79 °C and up to 13.7 °C for PET. Moreover, a maximum mitigation effect of an architectural shade is obtained at 32.6 °C for mean radiant temperature and 17 °C for PET. The highest reduction of PET (17.2 °C) is achieved by the combination of trees and the architectural shade. The outcomes of this research work provide useful design recommendations to improve outdoor thermal comfort.
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.