Wind Energy
Cyrille Rodrigue Enone Ellah; Alban Fabrice Lionel Epée; Judith Francisca Ngbara Touafio; Cyrille Mezoue Adiang; Ruben Martin Mouangue
Abstract
This study aims to identify a favorable area for wind energy exploitation in the Littoral region of Cameroon. The study used data collected by the meteorological service at Douala International Airport. A probabilistic method based on the Weibull distribution with two parameters was used to assess the ...
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This study aims to identify a favorable area for wind energy exploitation in the Littoral region of Cameroon. The study used data collected by the meteorological service at Douala International Airport. A probabilistic method based on the Weibull distribution with two parameters was used to assess the potential of the study area. Three methods were used to determine the parameters of this distribution: the maximum likelihood method, the WAsP method, and the energy pattern factor method. Statistical tests showed that the energy pattern factor method is more efficient, but the WAsP software provided acceptable results. The WAsP software was used to generate maps of the mean wind speed and wind power density at different heights. Two specific wind turbines were considered to calculate the annual energy production. The topography of the study area, the obstructions around the logger, and the roughness of the terrain were all taken into account when generating the maps for the different characteristics. Finally, maps at heights of 50 and 100 m were created using extrapolation techniques. Two zones with the highest power density were identified. In one of these locations, the wind power density could reach 54 W/m2 at a height of 100 m and the annual electrical output from a specific wind turbine could reach 1 GWh. The corresponding location is located at latitude 4.0661° North and longitude 9.8796° East.
M. G. Ghebrezgabher; A. K. Weldegabir
Abstract
The request to improve electric supply in Eritrea has motivated the country to look for alternative energy resources to enhance existing power. Eritrea, being in tropics, is well situated to harvest solar energy to improve its power supply status. Although several solar energy projects have been initiated, ...
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The request to improve electric supply in Eritrea has motivated the country to look for alternative energy resources to enhance existing power. Eritrea, being in tropics, is well situated to harvest solar energy to improve its power supply status. Although several solar energy projects have been initiated, very small has been done in the country. Therefore, this research paper aims to evaluate and investigate the regional solar energy potential (SEP) in Eritrea using remote sensing data and ArcGIS applications. The digital elevation model (DEM) data was adopted to estimate the SEP and suitability of energy in the country. In addition, areal solar radiation method is applied in ArcGIS 9.3 to extract the SEP and to evaluate suitability of this energy for the development of photovoltaics (PVs) power. The results revealed that approximately 69.03%, and 30.96% of the country was excellent and highly suitable to harness SEP, respectively, and only about 0.004% was considered as unsuitable. Therefore, this research may be useful as reference for future study and to motivate the country to improve its power supply using this alternative energy.
E. Guler; S. Yerel Kandemir
Abstract
Today, the use of renewable energy sources is increasing day by day. The essential advantages of wind energy are that it is clean, low cost, and unlimited. In this paper, the wind energy potential of provinces of the Marmara region in Turkey was evaluated by multi-criteria decision-making (MCDM) methods. ...
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Today, the use of renewable energy sources is increasing day by day. The essential advantages of wind energy are that it is clean, low cost, and unlimited. In this paper, the wind energy potential of provinces of the Marmara region in Turkey was evaluated by multi-criteria decision-making (MCDM) methods. In the study, TOPSIS and PROMETHEE methods were used for analysis criteria weights were determined by two different approaches. In the first approach, the criteria weights were taken equally. In the second approach, the criteria were weighted using the AHP method. When the methods were applied by taking the criteria weights equally, Balıkesir and Çanakkale were determined as wind priority provinces in potential, while Kocaeli and Sakarya took the last rank. After the criteria weights were determined via AHP when TOPSIS and PROMETHEE methods were applied, Balıkesir ranked first, and Kocaeli ranked last. Spearman's Correlation Coefficient determined the level and direction of the relationship between the rankings obtained from TOPSIS and the PROMETHEE method. When the methods were applied, the value of “0.636” indicated that the relationship between the rankings was “positive” and “moderate”. When the criteria were weighted with AHP and the methods were applied, the correlation coefficient was obtained as “0.909”. This value indicated a “positive” and “very high” level of relationship. It was determined that the ranking results obtained when the methods were applied after the criterion weights were calculated with AHP were more supportive of each other.
TITU THOMAS
Abstract
Highly unstable absorber layers along with costly Hole Transport Materials(HTMs) have been the main problems in the perovskite-based photovoltaic industry recently. Here in this study, we intend to meet both these problems by introducing a non-toxic cesium-based absorber layer and low-cost material, ...
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Highly unstable absorber layers along with costly Hole Transport Materials(HTMs) have been the main problems in the perovskite-based photovoltaic industry recently. Here in this study, we intend to meet both these problems by introducing a non-toxic cesium-based absorber layer and low-cost material, Graphene Oxide (GO) as the Hole Transporting Layer (HTL). We use the Solar Cell Capacitance Simulator Program (SCAPS) to study the various output parameters of the device with the structure GO/Cs2TiBr6/TiO2. Physical properties like the thickness of the absorber and hole transporting layers, the role of the layer interfaces, the effect of electron affinity, optical properties like the band gap of the absorber and hole transporting layer, electrical properties like the parasitic resistance, and finally the influence of operating conditions like the temperature on the working of the device was found out. The results show that a thickness of 1 μm for absorber and 0.1 μm for HTL is suitable. Also, the optimum value for front and back interface layers were 1010 cm-3 and 1016 cm-3 respectively. Resistance values were fixed at 2 for series and 40 for shunt resistance. The electron affinity doesn’t seem to have much effect on the device performance while with the increase in temperature the performance of the device deteriorated. The highest efficiency that we obtained from the optimized device was 15.3%. In short, this unprecedented work shows that Cs2TiBr6 - GO based devices are suitable candidates to achieve highly efficient, eco-friendly, all-inorganic perovskite solar cells.
Electricity Generation by Green Energy Sources
Cedric Okinda; Dominic Samoita; Charles Nzila
Abstract
The global electricity demand is rapidly growing due to population increase and industrialization. However, the reliance on fossil fuels and other non-renewable energy resources has resulted in climate change and other unsustainability-related issues. This study aims to determine the significant penetration ...
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The global electricity demand is rapidly growing due to population increase and industrialization. However, the reliance on fossil fuels and other non-renewable energy resources has resulted in climate change and other unsustainability-related issues. This study aims to determine the significant penetration levels of Solar PV on system operations and production costs based on the current year (business as usual scenario) and the accelerated Solar PV scenario (hypothetical future) in the Kenyan electricity generation system. A one-year dynamic analysis based on an hourly time step energy demand was performed using the Energy PLAN simulation tool. The current peak demand for electricity in Kenya was established to be 2,056.67 MW with an installed capacity of 3,074.34 MW with a 2.47% contribution by Solar PV while the curtailed energy was 285.51 GWh. The simulation results showed that large-scale installations of Solar PV can decrease CO₂-equivalent emissions from 0.134 Mt to 0.021 Mt. Both scenarios are presented in terms of their ability to avoid excess electricity production regarding system operations and production costs. Increasing the share of Solar PV in electricity generation is possible by as much as 39.56% (technical) and 30.54% (market economic) simulation. Additionally, the Solar PV electricity produced increased to 19.76 TWh/year from 11.90 TWh/year. Furthermore, the Market Economic Simulation showed that the total investment annual cost for Solar PV in the hypothetical future was low at 10 mEUR/Year. Therefore, large-scale installation of Solar PV in Kenya's energy system is feasible and economically viable based on technical analysis and economic analysis.
Seyyed A. Sina
Abstract
Multi-Megawatt wind turbines have long, slender and heavy blades that can undergo extremely wind loadings. Aeroelastic stability of wind turbine blades is of great importance in both power production and load carrying capacity of structure. This paper investigates the aeroelastic stability of wind turbine ...
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Multi-Megawatt wind turbines have long, slender and heavy blades that can undergo extremely wind loadings. Aeroelastic stability of wind turbine blades is of great importance in both power production and load carrying capacity of structure. This paper investigates the aeroelastic stability of wind turbine blades modeled as thin walled composite box beam, utilizing unsteady incompressible aerodynamics. The structural model incorporates a number of non-classical effects such as transverse shear, warping inhibition, non-uniform torsional model and rotary inertia. The unsteady incompressible aerodynamics based on Wagner’s function is used to determine the aerodynamic loads. Governing differential equations of motion are obtained using Hamilton’s principle and solved using extended Galerkin’s method. The results obtained in this paper, related to clarification of the effects of angular velocity and wind speed on the aeroelastic instability boundaries of the thin-walled composite beams. The obtained results are expected to be useful toward obtaining better predictions of the aeroelastic behavior of composite rotating blades.
Odai Mowafaq Fandi; Sharul Sham Dol; Mohammed Alavi
Abstract
Renewable energy and energy sustainability are vital in meeting the exponential growth of energy demand due to increasing population and industrial needs. However, the renewable energy source unpredictability is still a concern for continuous energy supplies. United Arab Emirates (UAE) has been investing ...
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Renewable energy and energy sustainability are vital in meeting the exponential growth of energy demand due to increasing population and industrial needs. However, the renewable energy source unpredictability is still a concern for continuous energy supplies. United Arab Emirates (UAE) has been investing in renewable energy technologies over the years particularly in solar, nuclear, wind, waste to energy and hydropower. However, this seems insufficient still and the shortage of fossil fuels has triggered an alarming energy discussion. Therefore, this work aims at looking for tidal energy feasibility in the UAE apart from reviewing the shortcomings of the existing renewable energy sources in the country. Tidal energy is new but is highly predictable and if applied properly, it could add to the sustainable solutions. Based on the preliminary study, tidal lagoons with the area of 102 km2 integrated with double cycle reversible turbines can be installed at the Saqar Port in Ras Al Khaimah, UAE. The location has an average of 1.6 m head difference is sufficient to meet 1% of the total UAE’s energy demand.
J. Taghinezhad; E. Mahmoodi; M. Masdari; R. Alimardani
Abstract
The use of ducted wind turbines is developing and various scientists in their studies investigate the performance, economic analysis, and energy production by these types of turbines at a lower cost. In this paper, the ratio of wind speed increment related to free stream wind speed and turbulence rate ...
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The use of ducted wind turbines is developing and various scientists in their studies investigate the performance, economic analysis, and energy production by these types of turbines at a lower cost. In this paper, the ratio of wind speed increment related to free stream wind speed and turbulence rate in a pre-designed duct used for a horizontal three-blade wind turbine was evaluated using a hot-wire anemometer sensor and data analysis methods. The duct installed in the University of Tehran Aerospace Faculty wind tunnel and flow characterization was performed by using CTA apparatus to measure and evaluate the wind flow turbulence in the throat section of the duct, where the wind turbine was installed. Wind speed analysis was done at different speed of the wind tunnel test section and shown that in the throat section of the duct the wind speed increased with a constant slope and in more analysis, it was found the wind speed in the duct throat can be increased to 2.5 up to 3 times of free stream flow speed at a different wind speed of wind tunnel test section. From spectral analysis, it was found that only a few peaks are included in the extracted frequency that shown low turbulence inside the duct it can be concluded that the flow disturbances will not have a significant impact on the performance of the wind turbine placed inside the duct throat.
Ruben Felix; Leonidas Sayas
Abstract
Plenty of works have treated the system expansion planning problem in the presence of intermittent renewable energy resources like solar. However, most of those proposals have been approached from scenarios of plenty of data, which is not the rule in developing countries, where principal investment actors ...
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Plenty of works have treated the system expansion planning problem in the presence of intermittent renewable energy resources like solar. However, most of those proposals have been approached from scenarios of plenty of data, which is not the rule in developing countries, where principal investment actors have recently switched their focus. In contrast of operation problems where existing literature can be successfully applied since it requires short-term historical time-series gathered from the same studied plants, proposals for planning problems are almost impossible to apply because of a lack of information and measurement about renewable resources in places where no renewable plants have been previously installed. In order to fill this information gap, this paper presents a novel methodology to synthesize solar production time-series on an hourly time scale, taking as inputs aggregate data such as monthly average, maximum or minimum values of basic parameters like global horizontal insolation, air temperature, and surface albedo. The methodology comprises five steps, from data gathering to calculating electrical power produced by a solar photovoltaic system. Three application tests are performed for different places in Chile, Slovakia, and Peru to validate the proposed methodology. The results show that the methodology successfully synthesizes time-series of output power, correctly replicates typical solar resource behavior, and slightly underestimates the produced solar energy, having a discrepancy of 2.4% in the yearly total.
Biomass Energy Sources
Asefa Keneni Negassa; addisu turura
Abstract
The objective of this study was to assess and evaluate the biogas yield of food wastes generated from the main campus of Ambo University's student cafeteria in a batch anaerobic digestion. Food waste from preprocessing and leftover from the student cafeteria were collected and measured. Standard techniques ...
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The objective of this study was to assess and evaluate the biogas yield of food wastes generated from the main campus of Ambo University's student cafeteria in a batch anaerobic digestion. Food waste from preprocessing and leftover from the student cafeteria were collected and measured. Standard techniques were used to analyze the physicochemical characteristics of the various food wastes, and the barrier solution was used to assess the amount of biogas and methane produced. The daily, weekly, monthly and yearly generated food wastes were: 1,283.02; 8,883.14; 38, 489.06; 204, 448.78kg respectively and the rate of generation of food waste was 0.37kg/capita/day. The moisture content ranged from 3.4±0.78% to 93.11±0.30%; total solids from 6.9±0.30% to 96.6±0.72%, VS of TS 82.1±0.59% to 98.1±0.75%; OC from 45.6±0.33% to 54.5±0.02%, C:N from 33.8% to 20.03±0.3%. The highest average biogas and percentage of methane were measured from FLM (12500±307.16ml and (81.65±2.58%) respectively while, the lowest average total biogas and percentage of methane were from the FPK (8590.33±260.77ml and (67.15±2.47%) respectively. The findings of this study revealed that the high quantity of food waste that was readily available at the study site and that could potentially be converted into high quantity and high-quality bio-methane which could serve two purposes: producing of bio-fuels and reducing environmental degradation from the open disposal of food waste.
S. Yerel Kandemir; M. Ozgur Yayli; Emin Acikkalp
Abstract
Renewable energy is one of the sustainable energy sources, the use of which has increased considerably in recent years. Today, wind energy is an essential renewable energy source that does not have a depletion problem. In this study, electricity generation from wind energy and installed power capacity ...
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Renewable energy is one of the sustainable energy sources, the use of which has increased considerably in recent years. Today, wind energy is an essential renewable energy source that does not have a depletion problem. In this study, electricity generation from wind energy and installed power capacity in Turkey were examined. First, the data set of electrical energy production (GWh) and installed power capacity (MW) between 2010 and 2019 was used. Then, electrical energy generation and installed power capacity were evaluated with trend analysis. Three different models were used in trend analysis, and the results obtained from these models were evaluated with MAPE, MAD, and MSD. Finally, the most suitable models for electric power generation and installed power capacity were determined by evaluating the results.
Biomass Energy Sources
Tegene Tantu Geta; Mahelete Tsegaye; Gemechu Yadeta; Tewabech Alemu; Berhanu Sugebo; Dagnachew Genene
Abstract
The low bulk density of wood wastes causes handling, storage, and transportation issues, limiting its large-scale application. Pelletization can solve this inherent problem by converting biomass into dense and compact pellets with regular shape and size. To evaluate the effect of particle size and binding ...
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The low bulk density of wood wastes causes handling, storage, and transportation issues, limiting its large-scale application. Pelletization can solve this inherent problem by converting biomass into dense and compact pellets with regular shape and size. To evaluate the effect of particle size and binding agents on pellets of carbonized Pinus patula sawdust, the particle size of 0.6 mm, 1.18 mm and 2.3 mm and binding agents of cow dung, molasses and wastepaper were used. The experimental results indicated that the addition of cow dung and molasses into the carbonized sawdust resulted in increase of calorific value, decrease of ash content and increase of fixed carbon. As a result, the maximum calorific value of 28.47 MJ/kg, ash content of 2.93%, and fixed carbon of 59.32% were obtained by using molasses.The calorific value of 25.8 MJ/kg, ash content of 6.03% and fixed carbon of 52.77% were obtained by using cow dung. Whereas, addition of wastepaper into carbonized sawdust resulted in lower calorific value of 22.3 MJ/kg, highest ash value of 8.35% and low fixed carbon of 43.2%. Therefore, the use of cow dung and molasses as a binder can be considered as a sustainable approach to improve the physicochemical properties of biomass pellets.
Energy Policy
Sh. Nourifard
Abstract
In this article, three topics of wind energy science, wind energy engineering and wind energy policy of Iran have been discussed. Deciding on wind energy in the country requires comprehensive information in these three areas. Due to the increase in the capacity of renewable energy in neighboring countries ...
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In this article, three topics of wind energy science, wind energy engineering and wind energy policy of Iran have been discussed. Deciding on wind energy in the country requires comprehensive information in these three areas. Due to the increase in the capacity of renewable energy in neighboring countries and global energy transition, as well as the high potential of Iran in the field of renewable energy, especially wind energy, its culture in the country and the transfer of concepts in simple language is necessary.
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.