Fuel Cell Technology
A. Mansouri; S. A. Alenabi; R. Gavagsaz-ghoachani
Abstract
The charge transfer coefficient is a dimensionless coefficient used in the kinetics of chemical reactions. In this paper, the effect of the charge transfer coefficient on hydrogen fuel cell characteristics such as polarization curve and power diagram in terms of current density and losses is investigated. ...
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The charge transfer coefficient is a dimensionless coefficient used in the kinetics of chemical reactions. In this paper, the effect of the charge transfer coefficient on hydrogen fuel cell characteristics such as polarization curve and power diagram in terms of current density and losses is investigated. The charge transfer coefficient affects the activation losses of the fuel cell and therefore affects the performance of the fuel cell. For this investigation, a basic sample is selected and the changes of charge transfer coefficient are studied on its characteristics. The obtained results show that with an increase in this factor, the activation loss decreases. In addition, increasing the charge transfer coefficient increases the maximum power point. The increase in the power of this point is more visible in lower values of the charge transfer coefficient and when this coefficient exceeds the value of 0.5, this effect becomes very small. Also, the appropriate value of this coefficient is determined to maintain the balance of the chemical reaction. The activity of the fuel cell is disrupted due to an excess amount of the coefficient.
Chemical Engineering
M. Zamani; R. Shafaghat; B. Alizadeh Kharkeshi
Abstract
Due to the necessity of utilizing renewable energies, the Archimedes screw turbine can be used as a power generation converter for the use of hydropower energy from river flows. A laboratory-scale model of this turbine with a scale of 1:6 has been designed and constructed. In the experimental tests, ...
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Due to the necessity of utilizing renewable energies, the Archimedes screw turbine can be used as a power generation converter for the use of hydropower energy from river flows. A laboratory-scale model of this turbine with a scale of 1:6 has been designed and constructed. In the experimental tests, the performance characteristics of the turbine were investigated based on variations in the flow rate and electrical resistance. The optimal flow rate for the turbine was determined with the aim of achieving maximum efficiency. The performance characteistics of the turbine at this flow rate were evaluated using empirical equations derived from the experimental tests for various parameters. These equations indicated higher values for these parameters at this flow rate. Furthermore, for the scaling of the Archimedes screw turbine, dimensionless numbers such as Froude number and flow rates ratio were introduced. The experimental results were extrapolated to the prototype scale at the optimal flow rate of 2.6 (lit/s), where the maximum turbine efficiency occurs. The results showed that the use of Froude scaling led to approximately 25% higher values for the performance characteristics of the turbine compared to scaling based on flow rates ratio.
Energy
A. W. Tahiru; S. U. Takal; E. D. Sunkari; S. Ampofo
Abstract
Although Ethiopia is one of the world's fastest-growing economies, access to sustainable energy and cutting-edge clean energy technology remains a major concern. The government is making significant efforts to generate renewable energy and provide more access to its citizens. Despite this, traditional ...
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Although Ethiopia is one of the world's fastest-growing economies, access to sustainable energy and cutting-edge clean energy technology remains a major concern. The government is making significant efforts to generate renewable energy and provide more access to its citizens. Despite this, traditional fuels (charcoal, fuel wood, dung cakes, and agricultural waste) account for around 87 percent of Ethiopia's energy use, and they pose a range of health and environmental risks. Solar, hydro, wind, and geothermal resources abound in the nation, but only 5% of the country's total hydroelectric capacity is being used; while, the rest is either underutilized or underdeveloped. An in-depth look at Ethiopia's renewable energy potential, as well as the opportunities and problems it faces, is presented in this review. With a combined installed capacity of over 7000 MW, hydropower and wind power are the most promising renewable energy sources in Ethiopia as of yet. It is hoped that this assessment will shed light on how Ethiopia can harness and maximize the use of its abundant renewable energy sources.
Energy
A. Haghani; M. Jahangiri; R. Riahi; M. Golali Jonaghani; A. Baharizadeh
Abstract
The use of fossil fuels leads to greenhouse gas emissions, global warming, and secondary consequences such as desertification and winds in the Middle East and Africa, including Egypt. The use of renewable energy is the most appropriate solution to prevent the emission of polluting gases. Egypt is one ...
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The use of fossil fuels leads to greenhouse gas emissions, global warming, and secondary consequences such as desertification and winds in the Middle East and Africa, including Egypt. The use of renewable energy is the most appropriate solution to prevent the emission of polluting gases. Egypt is one of the best places to use solar water heating systems, located in the solar belt. In this paper, for the first time, the best place to use solar water heater (SWH) systems is examined using TSOL 2018 R(1) software and climate data for residential apartments in 35 stations in Egypt. The results showed that Sharm el sheikh station with supplies 96.8% of its total heat needs is the most suitable station for using solar water heating systems. According to the studies performed, using solar water heaters in the studied stations generated good energy savings annually (production of 134.5 GWh of solar heat). Also, greenhouse gas emissions were significantly reduced (preventing the emission of about 39.2 tons of CO2 pollutants per year) and as a result, the government should turn to the use of clean and renewable energy.
Energy
S. Naranjo-Silva; D. Punina-Guerrero; J. Barros-Enriquez; J. Almeida-Dominguez; J. Alvarez del Castillo
Abstract
The present manuscript aims to identify the advantages and consequences of hydropower development, showing a view of trends finding the status and situation in Brazil, Colombia, and Ecuador. This study uses a non-experimental methodology based on a comprehensive literature review of relevant papers retrieved ...
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The present manuscript aims to identify the advantages and consequences of hydropower development, showing a view of trends finding the status and situation in Brazil, Colombia, and Ecuador. This study uses a non-experimental methodology based on a comprehensive literature review of relevant papers retrieved from 41 selected papers that are summarized covering different application areas in these selected countries. In addition, the non-experimental methodology is guided by a perspective design sequential with a qualitative phase defining two indicators that do a relation between the people and the installed capacity in megawatts (MW) and energy production in gigawatts hour (GWh). The results show Colombia has the main installed capacity and energy generation per capita, followed by Ecuador, and finally, Brazil. According to the models and studies, the general hydropower potential of Brazil, Colombia, and Ecuador decreases as time goes on because this renewable energy affects the water quality, interacting deeply with the surrounding environment. However, in South American countries only 34% of hydropower potential has developed.
Energy
M. Esmaeili Shayan; M. R. Hayati
Abstract
Having kilometers of asphalt road, yet with this heat going to waste, an attempt has been made in this research to extract the road's renewable energy heat. The purpose of the experiment is to compare the energy and exergy efficiency of various materials of asphalt solar water heaters (ASWH), as well ...
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Having kilometers of asphalt road, yet with this heat going to waste, an attempt has been made in this research to extract the road's renewable energy heat. The purpose of the experiment is to compare the energy and exergy efficiency of various materials of asphalt solar water heaters (ASWH), as well as heat transmission through the water tube and how friction affects exergy destruction. The water flow rate of one ASWH was 0.01 kg/s, while that of the other was 0.02 kg/s. Each ASWH has an area of 0.5 square meters. The copper tube is buried 10 mm deep in the asphalt. 15 degrees is the angle of inclination. The results indicate that the energy and exergy efficiencies are reasonably high for the water flow rate of 0.02 kg/s. Depending on the water flow rate, asphalt temperature, and sunlight intensity, the energy and exergy efficiencies changed from 32% to 65% and 5.8% to 16%, respectively. The water flow rate is an essential parameter for estimating the internal convective heat transfer coefficient and Reynolds number in order to calculate the friction factor in the copper tube based on internal convection heat transfer. In contrast, the friction factor is a consequence of the pressure loss and exergy degradation induced by friction.
Energy
M. Esmaeili Shayan; M. R. Hayati; G. Najafi; S. Esmaeili Shayan
Abstract
Energy democracy policymakers pay attention to planning to the formation of energy markets and exchanges of energy regions, diversification of energy resources, especially renewable resources, and global challenges due to greenhouse gas emissions. Over the introduction of concepts related to sustainable ...
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Energy democracy policymakers pay attention to planning to the formation of energy markets and exchanges of energy regions, diversification of energy resources, especially renewable resources, and global challenges due to greenhouse gas emissions. Over the introduction of concepts related to sustainable development, energy planning at the international level finds its place and goals in the direction of sustainable development, i.e., economic, social, environmental, and institutional dimensions. Energy democracy designs equations of great powers over energy with the aims of Resist, Reclaim, Restructure. This research focuses on free governments and energy democracy and the integration of priorities and methods to improve energy policy and analysis. No one policy instrument in isolation significantly impacts the energy democracy agenda. instead, all policies are essential for increasing this aim. They created new policy tools, supporting efforts to end fossil fuel dependence and connecting them to renewable energy. This research provides a starting point for improving the visibility of the energy democracy movement and constructing appropriate policies for different renewable energy transition options.
N. Norouzi; M. Fani
Abstract
The pandemic scenario caused by Covid-19 generated negative impacts. Covid-19 has made it clear that our daily lives depend to a high degree on access to energy. Therefore, now more than ever, it is necessary to promote new activities such as local food production, but also local energy capture. This ...
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The pandemic scenario caused by Covid-19 generated negative impacts. Covid-19 has made it clear that our daily lives depend to a high degree on access to energy. Therefore, now more than ever, it is necessary to promote new activities such as local food production, but also local energy capture. This article is an attempt to expose and quantify the benefits of a renewable energy transition in Ecuador post Covid-19 and post-oil. The generation, consumption, and reserves of oil in Ecuador were characterized, and the concept of energy transition was applied to evaluate the possibilities of integration of renewables, the progressive exit of thermal power plants, and future energy strategies. The year 2015 was taken as a basis and it was determined that energy use was 154.0 TWh / year, which corresponds to an end-user of approximately 147 TWh / year. The objective was to reduce this end-use demand to 80.0 TWh/year by 2055 through the integration of renewables and energy efficiency, for which 5 transition phases were planned until a 100% renewable system was obtained. It is concluded that the energy transition in Ecuador is technically possible and economically viable, without giving up the energy well-being that we currently enjoy. However, results show that even 100% renewable is not enough to face climate change.
Energy
M. Esmaeili Shayan; G. Najafi; B. Ghobadian; S. Gorjian
Abstract
Photovoltaic cells are a significant renewable energy source due to their cheap cost and renewability. In both warm sunny and colder and cloudier conditions, a-Si modules outperform c-Si modules on a normalized energy basis. This study investigated 1 m2 of amorphous photovoltaic silicon on curved surfaces. ...
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Photovoltaic cells are a significant renewable energy source due to their cheap cost and renewability. In both warm sunny and colder and cloudier conditions, a-Si modules outperform c-Si modules on a normalized energy basis. This study investigated 1 m2 of amorphous photovoltaic silicon on curved surfaces. The Taguchi and response surface methods were utilized to expand the model in real terms. Results demonstrated the technology gap in the use of silicon crystal photovoltaics is eliminated. The maximum power in the Taguchi method test is 59.87 W, while the minimum power is 57.84 W when the system is deployed on a flat surface, and the maximum power in the RSM Test is 61.14 W when the system is deployed on a hemispherical surface, and the minimum power is 56.6 W when the system is deployed on a flat surface. The minimal performance was 7.1% on a level surface. The flat surface produced 810 kWh, the cylindrical surface 960 kWh, and the hemisphere 1000 kWh. The NPV at Flat surface is $697.52, with a 34.81%, IRR and an 8.58-year capital return period. Hemisphere and cylindrical surfaces both get $955.18. The investment yield was 39.29% for cylindrical constructions and 40.47% for hemispheres. On the flat surface, doubling fixed investment improved IRR by 21.3%. The cylindrical system increased by 25.59% and the hemisphere by 24.58%. The developed simulation model is empirically evaluated using a MATLAB computer tool; the key findings from the validation procedure are reported in this study.
N. Norouzi
Abstract
Hydrogen energy has the advantages of low carbon and cleanliness, high energy density, and high conversion efficiency; it is expected to play a pivotal role in Eastern Asia and the MENA region’s energy transition. The research status and development prospects of various technologies in hydrogen ...
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Hydrogen energy has the advantages of low carbon and cleanliness, high energy density, and high conversion efficiency; it is expected to play a pivotal role in Eastern Asia and the MENA region’s energy transition. The research status and development prospects of various technologies in hydrogen production, hydrogen storage, and hydrogen use are analyzed. On this basis, specific technical paths for developing renewable energy and integrated energy service parks coupled with hydrogen energy are proposed. Solid polymer electrolyte (SPE) electrolysis hydrogen production and solid material hydrogen storage are the most potential development in directions of hydrogen production and hydrogen storage. Technologies such as hydrogen fuel cell and natural gas hydrogen mixture in the hydrogen use link should be simultaneously promoted. The organic combination of wind/light-abandoned hydrogen production by electrolysis of water, wind power/photovoltaic off-grid hydrogen production with fuel cell power generation, hydrogen refueling station supply, methanol production, and natural gas hydrogen mixing technology would effectively solve the uneconomical and transportation difficulties of renewable energy hydrogen production. At the same time, hydrogen energy can realize the interconnection of multiple energy networks, and its application prospects in the future integrated energy service parks are very broad.
M. Tamoor; M. Sagir; G. Abbas; M. Ans Zaka; P. ZakaUllah
Abstract
Developing countries like Pakistan are in serious energy crisis. Renewable energy resources are the best alternative for conventional energy sources. The use of indigenous resources to produce bioenergy is an excellent solution to meet the energy needs of developing countries. The aim of the study was ...
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Developing countries like Pakistan are in serious energy crisis. Renewable energy resources are the best alternative for conventional energy sources. The use of indigenous resources to produce bioenergy is an excellent solution to meet the energy needs of developing countries. The aim of the study was to design, construct and production of bioenergy generation from indigenous resources to fulfil bioenergy requirement for electricity, cooking and heating. This research introduces the Best Available Technology (BAT) and bioenergy plant was constructed with local materials at minimum cost to avoid economic burden on bioenergy production cost. An underground bio-digester unit with a volume of 10 cubic meter (7 m3 bioenergy digester tank plus 3 m3 bioenergy gas cap/holder) has been installed. The daily feed was approximately 160 kilogram of cow slurry (80 kg cow dung plus 80 litres/kg water). The retention period was approximately 44 days and the reported seasonal temperature was approximately 24˚C - 32˚C. The unit was thermally insulated, so the fluctuation in temperature was slightly about ±2˚C. In experimental setup, indigenous biomass resources were mixed with water in a mixing chamber. Whole mixture enters into digester through the inlet pipe and regularly feed up to selected retention time. Anaerobic bacteria decompose the biomass in the digester and produce bioenergy. A simulation was performed to estimate relevant model parameters from experimental data. The proposed model can predict methane production behaviour from some key indicators (such as organic matter and VFAs) in the anaerobic digestion process. Results obtained from the experiment showed that the plant could generate average volume of 3.18 m3 of bioenergy biogas at average pressure of 170 mbar in a day. Results also revealed that the rate of bioenergy generation increase with respect to time from 33 to 44 days of retention time, the pressure of bioenergy generated increase from 35 mbar to 175 mbar. From the results, it was observable that the more the pressure in the chamber, the more the volume of bioenergy generated; thus, at 175 mbars, it produced maximum volume of 3.2 m3 of bioenergy.
M. M. Mirzaei Darian; A. M. Ghorreshi; M. J. Hajatzadeh
Abstract
Solar energy is a feasible and efficient way to reduce environmental pollution which, in turn, can decrease the production of greenhouse gases. Iran with over 300 sunny days has a high potential for producing energy, including electricity through photovoltaic (PV) systems. Regarding this fact that Iran ...
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Solar energy is a feasible and efficient way to reduce environmental pollution which, in turn, can decrease the production of greenhouse gases. Iran with over 300 sunny days has a high potential for producing energy, including electricity through photovoltaic (PV) systems. Regarding this fact that Iran has the enormous resources of fossil fuels such as oil and gas, the government tends to expand its energy production by renewable systems, including photovoltaics. This paper is to evaluate the efficiency of photovoltaic system in one of the major provinces of Iran. In this study, a 4.8 kW photovoltaic power station in East Azerbaijan province was investigated. First, a simulation-analysis is carried out. Then the verification of the study is done using extracted experimental data. According to the results, the photovoltaic power plant generates 8334 kWh annually. Finally, the station is economically investigated. This economic analysis is carried out in accordance with the existing tariffs and policies in Iran.
H. Faridi; A. Arabhosseini; G. Zarei; M. Okos
Abstract
The commonly used energy in Iranian greenhouses is provided from gas or diesel fuel. As fossil fuels will be finished in the coming years, the utilization of renewable energies could be quite significant. In this research, the thermal potential of the soil profile was studied in Kouhsar, Alborz province, ...
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The commonly used energy in Iranian greenhouses is provided from gas or diesel fuel. As fossil fuels will be finished in the coming years, the utilization of renewable energies could be quite significant. In this research, the thermal potential of the soil profile was studied in Kouhsar, Alborz province, Iran, for utilizing the shallow geothermal energy in order to supply thermal demands of building like greenhouses. Therefore, the temperature sensors were set at the four depths of 30, 100, 200, and 300 cm as well as at the ground surface. The results showed that the greater the depth, the less fluctuation of the soil temperature as well as the greater the temperature difference of the soil profile against the ambient air temperature. These results suggest that the potential of the earth could be used to warm up or cool down in this location for an agricultural structure like greenhouse. The soil profile temperature behavior was modeled at different depths by two methods as heat transfer and empirical. The empirical model was simpler than the other one. As the possibility of using geothermal energy in this region has not been investigated. This research could be an effective step for using renewable energy for agricultural structures like greenhouses.
A. Belay Kassa
Abstract
Ethiopia is a land locked country, located in Horn of Africa. The country power generation does not meet the national demand of the people. The aim of the paper is to review a current status, future potential and barriers on development of renewable energy for power generations in Ethiopia. The approaches ...
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Ethiopia is a land locked country, located in Horn of Africa. The country power generation does not meet the national demand of the people. The aim of the paper is to review a current status, future potential and barriers on development of renewable energy for power generations in Ethiopia. The approaches would be use of primary and secondary data. The structural question is developed and data collected from experts. Secondary data were also collected from national published report, ministries brief and policy guides. The study used predominate renewable energy resource for power generation such as solar, wind, hydro, geothermal and waste to energy. Based on the result, the country utilization of the resources like solar, wind and geothermal with less than 1% with respect to the potential except hydro power which is less than 9% from the national reserve. The paper found that finical, technical, policy and regulation are the main barriers that faced on the development renewable energy. Key measurements are strengthened finical institution, establishing capacity building center, initiation active community participation, organizing institution to support development of renewable energy. This proposed measurements and policy issues were based on the evidence faced the country.
J. A. Oyewole; A. A. Olanrewaju
Abstract
Solar distiller was constructed and tested in this study. The purpose is to get a portable water from nearly any source available in a relatively cheaper means using a renewable solar energy. The result obtained clearly confirmed the reliability of this method to provide portable water especially in ...
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Solar distiller was constructed and tested in this study. The purpose is to get a portable water from nearly any source available in a relatively cheaper means using a renewable solar energy. The result obtained clearly confirmed the reliability of this method to provide portable water especially in a rural area of developing country like Nigeria where the supply of fresh water is inadequate. A local dirty stream that is constantly throughout the year served as the source of the brackish water was used for this work. Sample taken from this stream was distilled using the constructed double slope solar distiller. The incoming solar radiation from the sun is focused and concentrated on to solar water distillation unit. Analyzing the sample of the distillate, the pH value of the brackish feed water was 9.20 ±1.10 while that of the distillate was 8.10 ±1.06, which falls within the WHO limits of 6.5-8.5 for drinkable water.
Energy
F. Mohammad Alinezhad
Abstract
Dezful city, located in southwest of Iran, has a hot and semi-humid climate. In the past, architectures used design solutions to provide the cold of living space. Shavadoon is one of the most important design for reaching this goal. Shavadoon is an underground space in traditional buildings of Dezful ...
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Dezful city, located in southwest of Iran, has a hot and semi-humid climate. In the past, architectures used design solutions to provide the cold of living space. Shavadoon is one of the most important design for reaching this goal. Shavadoon is an underground space in traditional buildings of Dezful city designed with a trend of respect and protection of natural environment. Shavadoon, linked with its peripheral environment, provided an appropriate space for sheltering residents in summers hot weather without a need of energy of fossil fuels. Exploring the causes of thermal comfort in this underground space with no need to non-renewable energies was the aim of this article. In this article passive cooling of shavadoon was reviewed in a descriptive and analytic procedure. Results indicated that the architectural design of shavadoon is such that cool down the shavadoon through three types of cooling including the ground cooling, cooling through ventilation and evaporative cooling.
A. Zahedi Nejad; P. Zahedi Nejad
Abstract
The present paper describes analytical optimization and numerical simulation of a modern hydro-kinetic turbine. It was a tidal turbine with twin elliptic-rotors. The turbines were installed within the twin ducts inside of a tidal dam. There was a gap between each of the turbines and the ducts for allowing ...
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The present paper describes analytical optimization and numerical simulation of a modern hydro-kinetic turbine. It was a tidal turbine with twin elliptic-rotors. The turbines were installed within the twin ducts inside of a tidal dam. There was a gap between each of the turbines and the ducts for allowing vortex formation around each of turbines. The pitch angle distribution was optimized for highest energy extraction from water flow. The numerical simulations of the turbine have shown great power-coefficient that exceeds from 1.0 for tip-speed ratios greater than 3.5. According to power-coefficient curve, the runaway speed for the hydro-kinetic turbine was eliminated and the extracted power has increased with a second order function at higher tip-speed ratios. Based on obtained data, an axial hydro-kinetic turbine can not only absorb flow kinetic energy of incoming flow, but also can extract energy from parallel flows over each turbine. The power-coefficient curve against tip-speed ratio encounters with a break point around tip-speed ratio of 3.0. Simultaneously a strong vortex ring has formed around each of turbines. Flow trajectories illustrate how the hydro-kinetic turbine was able to absorb much more energy from external flows than conventional axial hydro-kinetic turbines.
A. Singh; P. Baredar
Abstract
In this paper sun situated photovoltaic (PV), fuel cell, biomass gasifier generator set, battery reinforcement and force molding unit have mimicked and advanced for an instructive establishment, Energy Center, Maulana Azad National Institute of Technology, Bhopal in the Indian condition of Madhya Pradesh. ...
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In this paper sun situated photovoltaic (PV), fuel cell, biomass gasifier generator set, battery reinforcement and force molding unit have mimicked and advanced for an instructive establishment, Energy Center, Maulana Azad National Institute of Technology, Bhopal in the Indian condition of Madhya Pradesh. The zone of the study range on the aide arranged of 23° 12' N scope and 77°24'E longitude. In this structure, the key wellspring of force is sun based sunlight based photovoltaic framework and biomass gasifier generator set while fuel cell and batteries were used as fortification supply. Hybrid optimization model for electric renewable test system has been used to reproduce off the framework and it checks the particular and money related criteria of this cross breed vitality framework. The execution of each section of this structure is analyzed in conclusion. The sensitivity examination was performed to upgrade the blend system at different conditions. In a perspective of the entertainment result, it is found that the expense of vitality of a biomass gasifier generator set, sunlight based on PV and power device hybrid vitality framework was observed to be 15.064 Rs/kWh.
