Environmental Impacts and Sustainability
Ali Sayyadi; Mohamad Javad Amiri
Abstract
One of the environmental problems today is the rising land surface temperature and the formation of heat islands in metropolitan areas, which have arisen due to the unplanned expansion of these cities. Satellite imagery is widely used in urban environmental studies to provide an integrated view and reduce ...
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One of the environmental problems today is the rising land surface temperature and the formation of heat islands in metropolitan areas, which have arisen due to the unplanned expansion of these cities. Satellite imagery is widely used in urban environmental studies to provide an integrated view and reduce costs and time. In this study, Landsat satellite imagery in TM, ETM+, and OLI sensors from 1984 to 2020, remote sensing techniques, and GIS is used to analyze the data, and SPSS software is employed to examine the correlation between the data. The results indicate that the land surface temperature in District 1 of Tehran has increased during the last 38 years. Moreover, land use in District 1 has changed significantly over this period, and urban land use increased from 16 % (1984) to 35 % (2020) while vegetation declined from 32 % to 14 %. The results of linear regression analysis show a significant correlation between satellite images and weather station data. The significance coefficient (Sig) in all stations is less than 0.05 with a 95 % confidence interval. Besides, the coefficient of variation (R) for all stations is above 80 %, and the coefficient R2 has a desirable value. The findings suggest that the trend of rising temperatures in District 1 of Tehran has become an environmental problem and the changes in land use such as declining vegetation and increasing the acceleration of urbanization are among the factors that affect it.
Renewable Energy Resources and Technologies
Sara Taheri; Ahmadreza Faghih Khorasani; Mohsen Mozafari Shamsi
Abstract
Desalination stands out as a prominent method for obtaining fresh water from saltwater sources. The focus of this study revolves around a dehumidifier-dehumidifier system within a closed air-open water desalination framework, exploring two distinct modes: one without integration with solar collectors ...
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Desalination stands out as a prominent method for obtaining fresh water from saltwater sources. The focus of this study revolves around a dehumidifier-dehumidifier system within a closed air-open water desalination framework, exploring two distinct modes: one without integration with solar collectors and the other incorporating solar collectors.Optimal conditions emerged with a fresh water circulation rate of 3 L/min and an incoming salt water flow rate of 1 L/min, resulting in a commendable maximum recovery ratio of 5.33%. Subsequently, in these optimal operating conditions, photovoltaic-thermal (PVT) panels were introduced to the desalination system, yielding insightful results. The output gain ratio (GOR), indicating the efficiency of converting heat to water evaporation, was 0.78 without connecting panels and 0.48 when panels were integrated. With panels connected, the desalination system achieved a peak fresh water production of 2.04 L/hr. Notably, the humidifier tower exhibited an impressive efficiency of 97%, while the dehumidifier tower operated at 40%. The solar collectors contributed significantly, meeting approximately 10% of the system's heating requirements and satisfying 7.3% of its electrical needs. The findings underscore the viability of integrating solar technology into desalination systems, showcasing not only increased fresh water output but also a noteworthy reduction in reliance on conventional energy sources. This innovative approach aligns with the global pursuit of sustainable and efficient water management solutions.
Advanced Energy Technologies
Ali Mostafaeipour; Mojtaba Qolipour; Hossein Goudarzi; Mehdi Jahangiri; Amir-Mohammad Golmohammadi; Mostafa Rezaei; Alireza Goli; Ladan Sadeghikhorami; Ali Sadeghi Sedeh; Seyad Rashid Khalifeh Soltani
Abstract
Fuel cells are potential candidates for storing energy in many applications; however, their implementation is limited due to poor efficiency and high initial and operating costs. The purpose of this research is to find the most influential fuel cell parameters by applying the adaptive neuro-fuzzy inference ...
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Fuel cells are potential candidates for storing energy in many applications; however, their implementation is limited due to poor efficiency and high initial and operating costs. The purpose of this research is to find the most influential fuel cell parameters by applying the adaptive neuro-fuzzy inference system (ANFIS). The ANFIS method is implemented to select highly influential parameters for proton exchange membrane (PEM) element of fuel cells. Seven effective input parameters are considered including four parameters of semi-empirical coefficients, parametric coefficient, equivalent contact resistance, and adjustable parameter. Parameters with higher influence are then identified. An optimal combination of the influential parameters is presented and discussed. The ANFIS models used for predicting the most influential parameters in the performance of fuel cells were performed by the well-known statistical indicators of the root-mean-squared error (RMSE) and coefficient of determination (R2). Conventional error statistical indicators, RMSE, r, and R2, were calculated. Values of R2 were calculated as of 1.000, 0.9769, and 0.9652 for three different scenarios, respectively. R2 values showed that the ANFIS could be properly used for yield prediction in this study
Renewable Energy Economics, Policies and Planning
Mahdieh Rezagholizadeh; Majid Aghaei; Omid Dehghan
Abstract
Concerning environmental pollution issues derived from fossil energy consumption, the application of renewable energies plays an important role in countries, especially in their energy sector policymaking. Since determining the relationship between different variables and renewable energy not only has ...
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Concerning environmental pollution issues derived from fossil energy consumption, the application of renewable energies plays an important role in countries, especially in their energy sector policymaking. Since determining the relationship between different variables and renewable energy not only has significant policy applications in energy sector but also is necessary in achieving sustainable development goals, this study assesses the impact of effective factors on the development of renewable energy consumption in Iran with emphasis on the role of foreign direct investment (FDI) and financial sector development (especially stock market development). This study applies Auto-Regressive Distributed Lag (ARDL) bounding test method over the period of 1978-2016. The research findings show that there is a causal relationship between foreign direct investment and the stock market and renewable energy consumption in Iran such that the increase of foreign direct investment and stock market development will increase the consumption of renewable energies in Iran. On the other hand, a growth in renewable energies consumption will significantly reduce CO2 emission in the long run. Besides, increasing FDI and stock market development will raise the economic growth of a country and, in return, increase CO2 emission.
Renewable Energy Resources and Technologies
Amin Habibzadeh; Samad Jafarmadar
Abstract
A considerable amount of waste heat is produced by internal combustion engines. Bottoming cycle application of Organic Rankine Cycles (ORC) is one of the promising technologies that recuperates the waste heat of engines. A lot of engine waste heat is released into the environment. There are a lot of ...
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A considerable amount of waste heat is produced by internal combustion engines. Bottoming cycle application of Organic Rankine Cycles (ORC) is one of the promising technologies that recuperates the waste heat of engines. A lot of engine waste heat is released into the environment. There are a lot of working fluids that can be applied in these cycles. As the engine waste heat temperature is extremely high, finding a suitable working fluid, which operates properly in the combined cycle, is challenging. In this paper, the thermodynamic analysis of ten working fluids including cyclohexane, HFE7000, HFE7100, n-hexane, n-pentane, R11, R123, R134a, R141b, and R245fa is conducted to observe the influence of different parameters on the system performance and introduce the most appropriate working fluid. Results indicated that, in the studied ranges, R134a had the best performances since (a) its thermal and exergy efficiencies were 17.39 % and 17.34 %, respectively; (b) the thermal efficiency of the engine increased by 9 %, and the net power of the system reached 7.5 kW. Furthermore, there was about 9 % reduction in fuel consumption. On the other hand, among the studied working fluids, cyclohexane operates as the least suitable one by possessing the minimum amounts.
Environmental Impacts and Sustainability
Mohammad Hossein Jahangir; Mahnaz Abolghasemi; Seyedeh Mahsa Mousavi Reineh
Abstract
Drought is considered as a destructive disaster that can have irreversible effects on different aspects of life. In this study, artificial neural network was used as a powerful means of modeling nonlinear and indefinite processes in order to simulate drought intensities at 7 synoptic stations of Khorasan ...
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Drought is considered as a destructive disaster that can have irreversible effects on different aspects of life. In this study, artificial neural network was used as a powerful means of modeling nonlinear and indefinite processes in order to simulate drought intensities at 7 synoptic stations of Khorasan Razavi from more than 35 years ago up to the year 2014. Input data were the calculations of the two indicators of PNPI and SPI by DIC software, and the output layer (drought intensity) was taken to the Matlab software and employed as the teaching data (from 25 years), experiment (from 5 years), and validation (from another 5 years). The 3-9-1 structure of the network of layers had the maximum accuracy with the error rate of less than 2 % and high correlation (more than 90 %). After trial and error for each station through sigmoid stimulation function in the Perceptron network, it was observed that the stations of Mashhad and Quchan had the minimum error and the maximum error was related to the station of Neyshabur. The results of comparisons and observations showed that the artificial neural network had high efficiency in simulation of the data. The obtained correlation amount of 0.999 for the base station represented the small error of the model in prediction. Drought forecasting was performed in this study by the trained algorithm in the artificial neural network without using the observation data. The results showed that rainfall, temperature, and speed models had a positive role in forecasting the provinces that would experience drought. Due to its lower amount of error, SPI indicator was selected for mapping, the findings of which showed that the highest drought intensity belonged to the near normal to normal wet lands.
S. Zeinali Heris; Farhad Oghazian; Mahmoud Khademi; Effat Saeedi
Abstract
In this study, the convective heat transfer and pressure drop in laminar flow of Al2O3/water and CuO/water nanofluids through square and triangular cross-sectional ducts have been numerically investigated using new technique. It has been assumed that there is constant heat flux boundary condition at ...
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In this study, the convective heat transfer and pressure drop in laminar flow of Al2O3/water and CuO/water nanofluids through square and triangular cross-sectional ducts have been numerically investigated using new technique. It has been assumed that there is constant heat flux boundary condition at walls. In addition, to include the presence of nanoparticles, the dispersion model has been used, and the system was solved numerically. Results show that by increasing the volumetric concentration and decreasing the size of nanoparticles, Nusselt number has been enhanced. Also, the Nusselt number increases by increasing the Reynolds number. In all cases, it has been observed that heat transfer coefficient of nanofluid increases in comparison with heat transfer coefficient of pure water. The results show that by adding nanoparticles, pressure drop increases in ducts. In square and triangular ducts, pressure drop is higher when we use CuO/water nanofluid instead of Al2O3/water nanofluid. In the same way, pressure drop increases by increase of faces of non-circular ducts.
Hossein Vaheed; S. Mohammad Mousavi; S. Abbas Shojaosadati; Hasan Galip
Abstract
Regarding some reported antimicrobial properties of tannins; Zymomonas mobilis was used to obtain ethanol from tannin-reduced carob pod extract (TR-CPE). Culture of 50 mL volume containing 7.5 g sugar at pH 5.5 and 0.03 g bacterial inoculums with shaking at 80 rpm was used. Using response surface methodology ...
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Regarding some reported antimicrobial properties of tannins; Zymomonas mobilis was used to obtain ethanol from tannin-reduced carob pod extract (TR-CPE). Culture of 50 mL volume containing 7.5 g sugar at pH 5.5 and 0.03 g bacterial inoculums with shaking at 80 rpm was used. Using response surface methodology (RSM), the maximum ethanol concentration of 5.34 % w/v (higher than that reported earlier, 4.01% w/v) was obtained at the optimized addition levels of yeast extract, peptone, and fermentation time; 0.13 g, 0.62 g, and 43.78 h, respectively. Carob pods extract (CPE) containing 62.23 gl-1 sugar was treated with 3 gl-1 gelatin to decrease its tannin content by 57.87 %. Sugar loss was not observed during gelatin treatment. The results revealed that there was no significant difference in ethanol production, yield, and productivity between TR-CPE and non-TR-CPE. In conclusion, tannin showed no inhibiting effect to maximum ethanol production by Zymomonas mobilis.
M. Ziaei-Rad; Iman Samea
Abstract
This paper deals with numerical study of semi-finite incompressible flow of air over two blocks with different heights in the presence of a condensing-source, dispensing- contaminant in the flow, in both steady and unsteady states. The numerical solution of governing PDE equations are constructed by ...
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This paper deals with numerical study of semi-finite incompressible flow of air over two blocks with different heights in the presence of a condensing-source, dispensing- contaminant in the flow, in both steady and unsteady states. The numerical solution of governing PDE equations are constructed by a finite-volume method applied on structured grid arrangement. The effects of air flow velocity, contaminant source length and position, and the blocks height ratio on the concentration distribution, the mass transfer level and the time of transportation are studied. The results indicate that by increasing the inflow Reynolds number, the amount of contamination reaching the blocks and also the amount remaining between them decrease, while the mass transfer rate increases. It is shown that the closer the contaminant source to the blocks, the higher the mean concentration accumulating between the two blocks. It is also found that increasing the blocks height ratio makes an ascending trend to the time for the arrival of contaminant to the blocks walls, though the slopes of time-lines are different for each case.
Advanced Energy Technologies
Marzieh Moein; Somayeh Pahlavan; Mehdi Jahangiri; Akbar Alidadi Shamsabadi
Abstract
The electricity economy and its excessive consumption have become one of the main concerns of the Iranian government for many years. This issue, along with recent droughts, shows the need to use renewable energy that is free and clean and does not require water. In addition, due to the high cost of cable-laying ...
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The electricity economy and its excessive consumption have become one of the main concerns of the Iranian government for many years. This issue, along with recent droughts, shows the need to use renewable energy that is free and clean and does not require water. In addition, due to the high cost of cable-laying and maintenance of power lines, it is not at all an option at all distances over the development of the national electricity grid. Therefore, it is important to find a distance for farther distances so that the use of renewable energy systems can be superior to the national electricity grid. According to related studies conducted so far, nothing has been done in this regard in Iran untill private-sector investors realize that, for what distances from the national grid, the network development is not cost-effective compared to using renewables. Therefore, in the present work, by using NASA's wind and solar data, 102 stations in Iran were investigated using the HOMER software. The studied system is a solar-wind one backed up by batteries and diesel generator for emergency conditions. The results showed that the average total net present cost of the solar-wind hybrid system in Iran was to provide a daily average electricity load of 5.9 kWh of a residential building with a peak load of 806 W equal to $ 12415, which could on average provide 95.3% of the building's needs by renewable energy. The average minimum distance from the national grid is 593 m for the cost-effective use of renewable energy.
Renewable Energy Resources and Technologies
Saeed Karimian Aliabadi; Sepehr Rasekh
Abstract
In this study, an unsteady aerodynamic simulation is performed to realize the influences of platform surge motion on the aerodynamic performance of a high capacity offshore floating wind turbine. A dynamic model with pitch angle control system is utilized to propose a more realistic model of wind turbine ...
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In this study, an unsteady aerodynamic simulation is performed to realize the influences of platform surge motion on the aerodynamic performance of a high capacity offshore floating wind turbine. A dynamic model with pitch angle control system is utilized to propose a more realistic model of wind turbine and also achieve the rated condition of the rotor. The transient effect of platform surge motion on power coefficient, thrust coefficient and blade pitch angle also is investigated. The 5 MW NREL wind turbine is selected for the simulations. The unsteady aerodynamic model contains unsteady blade element momentum method, dynamic stall and dynamic inflow models. The in-home aerodynamic code and the control system model are implemented in MATLAB/SIMULINK software. It is revealed that reduction in mean power coefficient at tip speed ratios less that 7 is expected by amount of 12-15 % at surge amplitude of 2m and frequency of 0.1 Hz. For high tip speed ratios, the trend is reverse with respect to fixed-platform case. The mean thrust coefficient is also reduced for many tip speed ratios with maximum loss of 32 %. The mean blade control pitch angle is increased due to the surge motion. Since the influence of changing amplitude and frequency of disturbances depends on the tip speed ratio, therefore the special bound of this parameter is being proposed.
Renewable Energy Resources and Technologies
Ashkan Gholami; Aryan Tajik; Shahab Eslami; Majid Zandi
Abstract
The current study investigated the feasibility of renewable energy harvesting to meet the energy need of a dairy farm in Shahroud, Iran. Therefore, considering the available renewable resources including solar, wind, and biomass in the site and the electrical demand of the farm, the techno-economic and ...
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The current study investigated the feasibility of renewable energy harvesting to meet the energy need of a dairy farm in Shahroud, Iran. Therefore, considering the available renewable resources including solar, wind, and biomass in the site and the electrical demand of the farm, the techno-economic and environmental analyses were carried out. By using Homer software, the optimized system was selected. It was shown that although there was wind potential within the farm site, the most economical system would be a system consisting of a 100 kW biomass power plant and a 169 kW PV plant. Furthermore, by using RETScreen software, the economic and environmental analyses for the selected system were carried out. The simple and equity paybacks were 5.8 and 4.2 years for the proposed system, which confirmed the economic feasibility of the proposed system. Moreover, the gross annual GHG emission would be reduced by 91.5 %. The techno-economic and environmental analyses conducted in the current paper confirmed that the proposed system could be easily extended for other dairy farms, which resulted in a significant increase in the energy ratio of the dairy farms.
Environmental Impacts and Sustainability
Alireza Taheri-Rad; Abbas Rohani; Mehdi Khojastehpour
Abstract
Environmental and economic aspects are two remarkable pillars toward a sustainable agro-system. Accordingly, this study aimed to assess the sustainability of autumn rainfed agro-systems in northern Iran by the Eco-Efficiency (EF) indicator. The data of the production processes of wheat, barley, canola, ...
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Environmental and economic aspects are two remarkable pillars toward a sustainable agro-system. Accordingly, this study aimed to assess the sustainability of autumn rainfed agro-systems in northern Iran by the Eco-Efficiency (EF) indicator. The data of the production processes of wheat, barley, canola, and triticale were collected in the three crop years of 2016-2019. Results indicated that the canola production system with 720 kgCO2eq ha-1 had the highest greenhouse gas (GHG) emissions; however, wheat with 604 kgCO2eq ha-1 was attributed to the lowest GHG emissions. The results of the economic analysis also highlighted that the barley production system had the lowest while the canola production system had the highest production costs. The canola production system had the highest profitability, while the barley production system had the lowest in terms of net income and average benefit to cost ratio indicators. The EF indicator for wheat, barley, canola, and triticale was determined to be 1.4, 0.6, 1.8, and 1.1, respectively, indicating the highest EF value for the canola production system.
Mahboobe Sabaghian; Fateme Ahmadi Boyaghchi
Abstract
Energy, exergy and exergoeconomic (3E) evaluation are performed to assess the performance of a NH3/H2O cycle integrated with parabolic trough solar collectors (PTSC). To provide continuous electricity produced by generator when solar beam radiation is insufficient a stabilizer temperature subsystem is ...
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Energy, exergy and exergoeconomic (3E) evaluation are performed to assess the performance of a NH3/H2O cycle integrated with parabolic trough solar collectors (PTSC). To provide continuous electricity produced by generator when solar beam radiation is insufficient a stabilizer temperature subsystem is utilized. The major thermodynamic parameters and climate conditions variations are selected to investigate, for their effects on the energy efficiency, exergy efficiency and unit cost of electricity of the overall system. The results reveal that the solar collectors exhibit the worst exergy and exergoeconomic performance, so that when system is only fuelled by solar energy, elevation of solar beam irradiation around 40% reduces the efficiencies and electricity production cost within 23% and 0.4%, respectively. It is found that the increment of ammonia basic concentration, turbine inlet pressure, evaporator inlet temperature and evaporator pinch temperature lead to elevation of energy and exergy efficiencies and decrement of electricity production cost. Then, the single and multi-objective optimizations are performed to maximize the energy and exergy efficiencies and minimize the electricity production cost based on genetic algorithm (GA). Results indicate that the electricity production cost obtained through economic optimization is less than around 2% and 2.2% compared to the optimization based on the first and second laws of thermodynamics. Multi objective optimization causes reduction of electricity production cost around 14% and enhancement the energy and exergy efficiencies 8.5% and 6.7%, respectively too.
Renewable Energy Resources and Technologies
Ali Mostafaeipour; Mohammad Saidi Mehrabad; Mojtaba Qolipour; Mohadese Basirati; Mostafa Rezaei; Amir Mohammad Golmohammadi
Abstract
The present study aimed at ranking and selecting the superior geothermal project for hydrogen production in 14 provinces of Iran using a multi-objective optimization fuzzy hybrid approach through analyzing the ratio (fuzzy Moora) and expanded entropy weighting method. In this research, the extended entropy ...
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The present study aimed at ranking and selecting the superior geothermal project for hydrogen production in 14 provinces of Iran using a multi-objective optimization fuzzy hybrid approach through analyzing the ratio (fuzzy Moora) and expanded entropy weighting method. In this research, the extended entropy weighing method and the Fuzzy-Moora approach were utilized to weigh the criteria and project the ranking, respectively. In this research, 13 criteria for ranking the geothermal projects in Iran have been selected for hydrogen production. At first, the technical-economic feasibility of the projects was carried out in Homer software, and then the ranking process was performed with the proposed hybrid approach. The results showed that among 14 studied provinces using geothermal energy, the provinces of Bushehr, Hormozgan, Isfahan, Mazandaran, East Azarbaijan, Fars, Qazvin, Zanjan, Ardebil, Khorasan Razavi, Kerman, Sistan and Baluchestan, South Khorasan and West Azarbaijan were ranked in that order in terms of hydrogen production.
Renewable Energy Resources and Technologies
Farhad Amiri; Mohammad Hassan Moradi
Abstract
In the power system, frequency stability is critical. The wind turbine oscillates (depending on the wind speed) and is of low inertia. Thus, wind turbines face the issue of power system frequency stability. Since the power system's resources are interconnected via communication networks, the presence ...
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In the power system, frequency stability is critical. The wind turbine oscillates (depending on the wind speed) and is of low inertia. Thus, wind turbines face the issue of power system frequency stability. Since the power system's resources are interconnected via communication networks, the presence of time delay also affects the frequency stability of the power system. When a disturbance occurs in the power system due to load or distributed generation sources (wind turbine), it leads to frequency deviations in the power system, exhibiting low damping speed. Although large conventional generators in the power system provide sufficient inertia and reduce frequency deviation, the damping speed of frequency fluctuations is slow, which may be due to time delays between power system resources. In this paper, virtual damping (a proposed method) is used to accelerate the damping of frequency deviations caused by load disturbances, distributed generation source disturbances, and the time delay between power system resources. The results of the proposed method are compared to those obtained using the conventional method in this field, demonstrating the superiority of the proposed method. The proposed method reduced frequency deviations in the power system caused by disturbances and time delays by 67 % (a 67 % improvement over existing methods in this field) and increased the damping speed of the frequency deviations by 62 % (a 62 % improvement over the methods used in this field).
Advanced Energy Technologies
Ming Hung Lin; Juin Hung Lin; Mamdouh El Haj Assad; Reza Alayi; Seyed Reza Seyednouri
Abstract
The optimal combination of distributed generation units in recent years has been designed to improve the reliability of distributed generation systems as well as to reduce losses in electrical distribution systems. In this research, the improved Genetic Algorithm has been proposed as a powerful optimization ...
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The optimal combination of distributed generation units in recent years has been designed to improve the reliability of distributed generation systems as well as to reduce losses in electrical distribution systems. In this research, the improved Genetic Algorithm has been proposed as a powerful optimization algorithm for optimizing problem variables. The objective function of this paper includes power loss reduction, hybrid system reliability, voltage profile, optimal size of distributed generation unit, and finally improvement of the construction cost of combined wind and solar power plants. Therefore, the problem variables are subject to reliable load supply and the lowest possible cost during the optimization process. In order to achieve this goal in this study, the IEEE standard 30-bus network is examined. The results of the system simulation show the reduction of total system losses after DG installation compared to the state without DG and the improvement of other variable values in this network. This loss index after installing DG in the desired bus has a reduction of about 200 kWh during the year and has a value equal to 126.42 kWh per year.
Somayeh Choobin; Bahram Hosseinzadeh Samani; Zahra Esmaeili
Abstract
In recent years, increasing the awareness on the environmental problems, especially global warming, has increase the concerns about the impact of emissions on the global climate. The current study was conducted to evaluate and analyze the environmental effects of rapeseed production in the form of life ...
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In recent years, increasing the awareness on the environmental problems, especially global warming, has increase the concerns about the impact of emissions on the global climate. The current study was conducted to evaluate and analyze the environmental effects of rapeseed production in the form of life cycle using SimaPro software with the aim concentration on climate changes and impact of acidification. In order to perform the experiments, 1 tone rapeseed was used as operational unit. The required data was collected from 30 farms in Izeh city. Ten environmental indexes including depletion of groundwater resources, potential to acidification, potential to eutrophication, potential to global warming, ozone depletion potential, human toxicity potential, potential to toxicity of fresh water and marine fish, potential to environmental toxicity, potential to photochemical oxidation were investigated in this research. Results showed that the amount of greenhouse emissions for rapeseed was equal to 112.73 kg of carbon dioxide equivalent. It was also revealed that chemical fertilizer had the highest share among the evaluated inputs within the life cycle. Results obtained in this survey indicated that management of nutrients and pesticides can be considered as a concentration point for optimizing the environmental influences of rapeseed production in the related region.
Ali Mostafaeipour; Mohammad Saidi-Mehrabad; Mostafa Rezaei; Mojtaba Qolipour
Abstract
The energy insecurity, environmental pollution, climate change and even reduced rainfall in some countries are prime examples of consequences of the world’s excessive reliance on fossil fuels. This study suggests that in some southern islands and coastal areas of Iran, two such problems, ...
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The energy insecurity, environmental pollution, climate change and even reduced rainfall in some countries are prime examples of consequences of the world’s excessive reliance on fossil fuels. This study suggests that in some southern islands and coastal areas of Iran, two such problems, namely the growing shortage of potable water and air pollution can be addressed by building a wind-powered seawater desalination plant at the locations. To evaluate such project, first the sites that may provide the highest efficiency need to be identified. In this study, 10 ports and 5 islands in southern Iran, which suffer from water shortage but have access to seawater, are identified as preliminary candidate sites for such project. The criteria influencing the suitability of a location are considered to be wind power density, economic feasibility, topographic condition, frequency of natural disasters, population, and the wind farm’s distance from desalination facility. After analyzing and weighting the criteria, the locations are ranked using the ELECTRE III method, and the results are validated using the PROMETHEE method. In conclusion, the results of ranking techniques show that Qeshm Island is the best location for construction of a wind-powered seawater desalination plant.
Renewable Energy Economics, Policies and Planning
Mohammad Ameri; Arian Gerami
Abstract
According to the previous pieces of research, the building sector consumes about 40 % of total yield energy and produce one-third of GHG pollution emission. This point shows the significant potential in two aspects of energy optimization and pollution reduction in this field. The purpose of this research ...
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According to the previous pieces of research, the building sector consumes about 40 % of total yield energy and produce one-third of GHG pollution emission. This point shows the significant potential in two aspects of energy optimization and pollution reduction in this field. The purpose of this research as a case study is to construct a residential building and develop the paths for reaching a zero-energy building, considering GHG emissions in the climate of Tehran, Iran. In thirty scenarios of this study, solar panels, solar water heaters, ground source heat pumps, and combined heat and power generators were selected to provide the required power and energy in the building. All three passive, single active, and hybrid active scenarios were defined and analyzed with respect to technical and economic factors. In all of the defined scenarios, the conditions are two-folded: (a) considering the effect of national profits, fuel saving, and pollution reduction and (b) without considering them so that the results would become more realistic. In the end, three different types of conclusions were made with respect to macro-engineering, energy, and economic perspectives. Statistical conclusions based on a questionnaire filled by 50 people and the perspective of achieving NZEB definition are presented.
Renewable Energy Resources and Technologies
Amir Goshadrou
Abstract
Glycyrrhiza glabra residue (GGR) was efficiently subjected to concentrated phosphoric acid (PA) pretreatment with/without surfactant assistance, and promising results were obtained following separate enzymatic hydrolysis and fermentation (SHF) of the biomass. Pretreatment was carried out using 85 % PA ...
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Glycyrrhiza glabra residue (GGR) was efficiently subjected to concentrated phosphoric acid (PA) pretreatment with/without surfactant assistance, and promising results were obtained following separate enzymatic hydrolysis and fermentation (SHF) of the biomass. Pretreatment was carried out using 85 % PA either at 50 or 85 °C with 12.5 % solid loading for 30 min. In parallel experiments, the intact GGR was impregnated in 2 % (w/w) surfactant (Polyethylene glycol) aqueous solution prior to the PA pretreatment. Consequently, the pretreated materials were subjected to enzymatic hydrolysis (50 °C, 72 h) using 25 FPU/g cellulase, and the most digestible biomass was nominated for conversion to bioethanol. Substantial improvement in digestibility of GGR (~92 % hydrolysis yield) was observed following surfactant-assisted PA pretreatment, whereas digestibility yield from the untreated biomass was only 16.1 %. Consequently, the ethanol production form GGR was significantly enhanced by 19.7-fold through separate hydrolysis and fermentation of biomass. Different analytical approaches including water retention value, Simons’ staining, and crystallinity together with FESEM imaging revealed that the improved surface hydrophilicity, increased substrate accessibility to enzyme, and decreased crystallinity could be the major effects of PA pretreatment, leading to higher susceptibility of GGR to enzymatic hydrolysis and subsequent ethanol production.
Renewable Energy Resources and Technologies
Rahul Dogra; Sanjay Kumar; Nikita Gupta
Abstract
The use of these conventional resources causes continuous depletion of fossil fuels and increased greenhouse effect. Solar power is the major renewable resource used for power generation across the globe. Solar energy activities depend on the available potential of any geographical location. Therefore, ...
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The use of these conventional resources causes continuous depletion of fossil fuels and increased greenhouse effect. Solar power is the major renewable resource used for power generation across the globe. Solar energy activities depend on the available potential of any geographical location. Therefore, prior to the installation of solar technologies for these activities, estimation of solar potential is very important due to costly technologies. Data of solar potential is not present at every location in Himachal Pradesh (H. P.) due to the high cost of measurement instruments. The objective of this study includes the solar potential estimation for 12 cities of the H. P. The present study could be divided into two parts. Initially, Artificial Neural Networks (ANNs) are utilized to estimate global sun radiation utilizing meteorological and geographical data from 23 places. The ANN model with seven input parameters including latitude, longitude, altitude, air temperature, humidity, pressure, and wind speed were used to estimate the solar irradiation. Statistical indicators including Mean Absolute Percentage Error (MAPE) were used for the performance evaluation of these ANNs. The minimum MAPE value was obtained to be 2.39 % with Multi-Layer Perception (MLP) architecture 7-11-1. For the 12 districts of the H. P., the acquired network 7-11-1 was utilized to estimate Global Solar Radiation (GSR). The output of ANN model was implemented in Geographic Information System (GIS) environment to obtain the solar potential map for each month. The available map of the present study may be helpful for solar application in each district.
Advanced Energy Technologies
Gunasagar Sahu; Hifjur Raheman
Abstract
A solar energy operated two-row weeder was developed for weeding in wetland paddy crop. Its major components are power source, power transmission system, weeding wheels, and a float. The power source comprised a DC motor, solar panel, and power storage unit with maximum power point tracker and motor ...
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A solar energy operated two-row weeder was developed for weeding in wetland paddy crop. Its major components are power source, power transmission system, weeding wheels, and a float. The power source comprised a DC motor, solar panel, and power storage unit with maximum power point tracker and motor controller. Solar panel/power storage unit through a motor controller supplied power to the DC motor and it was transmitted to the shaft of the weeding wheel through a dog clutch. A pair of wheels attached with jaw tooth and plane blades at wheel circumference was used for carrying out weeding and movement of the weeder in the field. A float was used to prevent sinkage of the weeder in soft soil which, in turn, ensured stability during operation. The developed weeder could do weeding at a rate of 0.06 ha per hour with field efficiency, weeding efficiency, and plant damage of 83.3 %, 83 % and 2-3 %, respectively. As compared to cono-weeder, the cost of weeding was 41.2 % lower due to higher field capacity and fewer labor requirements. Annual use less than 4.13 ha for the developed weeder was found uneconomical for carrying out weeding. The developed powering system comprising solar photovoltaic panels could supply power to do weeding continuously for 2 hours with a maximum discharge of 20 % from the battery.
Renewable Energy Resources and Technologies
Yuvaperiyasamy Mayilsamy; Senthilkumar Natarajan; Deepanraj Balakrishnan
Abstract
This experimental study investigates the performance of a single-slope solar desalination with a finned pond, considering varying glass cover angles, water depths, and the usage of sensible and latent heat materials for four different saline water types. Conventional solar stills (CSS) produce less distillate; ...
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This experimental study investigates the performance of a single-slope solar desalination with a finned pond, considering varying glass cover angles, water depths, and the usage of sensible and latent heat materials for four different saline water types. Conventional solar stills (CSS) produce less distillate; therefore, some design changes were implemented by integrating a finned pond into the conventional solar still (CSS-FP). Additionally, paraffin wax and bricks were placed inside the solar still to enhance thermal storage capacity. The solar still is constructed with galvanized steel for the base and side walls, while the basin is covered with tempered glass. Thermal conductivity is improved by applying black paint on the sides. The finned pond enhances the heat absorption and distribution process, consequently increasing the evaporation rate within the still. The experiment was conducted in Pongalur, Tamil Nadu, India (10.9729° N, 77.3698° E). The maximum distillate production was achieved at a 35° glass cover angle and a 7 cm water depth. Desalination was performed on four saline liquids: bore water (BW), seawater (SW), leather industry wastewater (LW), and plastic industry wastewater (PW). BW exhibited the highest yield due to its lower density and salinity. Chemical analysis of the desalinated water suggests its suitability for home use. Economic research reveals a payback period of 230 days, confirming the financial feasibility of the solar still. Hence, it is concluded that the proposed CSS-FP can increase productivity compared to the CSS under different conditions.
Ghazanfar Shahgholian
Abstract
The hydro turbine dynamics have a considerable influence on the dynamic stability of power system. In the study of dynamic stability, the system is modeled by the linear differential equations (small signal analysis). Small signal stability of power systems is needed in all conditions and ...
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The hydro turbine dynamics have a considerable influence on the dynamic stability of power system. In the study of dynamic stability, the system is modeled by the linear differential equations (small signal analysis). Small signal stability of power systems is needed in all conditions and only is dependent on the conditions of power system performance before commotion occurrence. This paper provides an analysis of the small signal stability in a hydropower plant equipped with low head Kaplan turbine connected as single-machine infinite-bus (SMIB) power system. The dynamical behaviors withrepresentative characteristics are identified and studied in details. The model of system is described by state-space equations. The eigenvalues analysis is used to show the effects of change in parameters for damping load angle and speed oscillations through the excitation and governor subsystems. Finally, results of theoretical analyses are verified by time-domain simulations under different system conditions and operating loads.
