Electricity Generation by Green Energy Sources
Sh. Momen; J. Nikoukar; M. Gandomkar
Abstract
Global warming and prices of energy carriers within political conflicts between different nations, are some of the problems for traditional energy production and economic dispatch. In traditional generation systems, about 25 percentage of energy is wasted, and the presence of Distributed Energy Resources ...
Read More
Global warming and prices of energy carriers within political conflicts between different nations, are some of the problems for traditional energy production and economic dispatch. In traditional generation systems, about 25 percentage of energy is wasted, and the presence of Distributed Energy Resources (DERs) such as Photovoltaic, Wind Turbine and wind farms, Fuel Cell, and the Combined Heat and Power can reduce fuel consumption, pollution, transmission losses, and increase the microgrid productivity. In this paper, a complete energy management framework in a microgrid is proposed by considering the load distribution constraints using Improved Shuffled Frog Leaping Algorithm (ISFLA) algorithm, in which it determines the exact share of energy production or consumption for different units. The proposed scheme is used to select the best arrangement of DERs in the power grid, which the output of which is to determine the number and optimal location of DERs in the several bus-bars of the grid. Then, the Independent System Operator (ISO) determines the quantity of energy exchange and consumption by considering the load distribution constraints. Boilers and CHPs have also been used to maintain the balance between the production of thermal power by energy sources and thermal demands. In addition, the Demand Response Program has been used with the aim of smoothing the load curve and reducing the operating costs. Finally, the proposed method is implemented and simulated on the IEEE 69 and 118 bus systems using MATLAB, which comparing the output results with existing algorithms, shows the superiority of the proposed method.
Electricity Generation by Green Energy Sources
S. Poursheikhali
Abstract
In this paper, an energy harvesting assisted wireless network is considered where a source, contrary to the conventional networks, harvests its required energy via two independent energy channels. In addition, we assume a destination terminal, which receives interference signals along with the data transferred ...
Read More
In this paper, an energy harvesting assisted wireless network is considered where a source, contrary to the conventional networks, harvests its required energy via two independent energy channels. In addition, we assume a destination terminal, which receives interference signals along with the data transferred by the source. In this model, the source is considered to scavenge energy from the destination's broadcasted signal and ambient interference signal. We model the energy and data channels via Rayleigh-Racian channel model. Then, the system outage probability is obtained after analyzing the outage probability of energy and data channels. Moreover, another scenario in which the source is assumed to harvest energy from only the destination terminal is investigated. Computer simulations are conducted to evaluate the effectiveness of the proposed approach, and the impacts of different system parameters on the system outage probability are investigated. The results indicate the outperformance of the scenario in which energy harvests via two channels compared to the case where only one energy harvesting channel exists. In addition, the overall system outage highly degrades when outage in energy channels decreases, especially in the first scenario.
S.Ollah Mohammadi-Aylar; M. Almassi; H. Bakhoda
Abstract
Due to the needs of modern societies to provide their energy fully or partially from the renewable energy sources and its necessity as a main principle of sustainable development, its necessary to assess and evaluate renewable energy and its integrating for utilizing a part of consumed energy for societies ...
Read More
Due to the needs of modern societies to provide their energy fully or partially from the renewable energy sources and its necessity as a main principle of sustainable development, its necessary to assess and evaluate renewable energy and its integrating for utilizing a part of consumed energy for societies from cheap energy resource and solving the ecological and social problems. Despite of great potentials of Ardabil province in agriculture, water streams, climatic precipitation and climatic conditions, the necessity of appropriate investments in order to better exploitation form these capabilities (renewable energy) increases. The goal of this research is to potentiometry for the exploitation of renewable energies (solar, wind, biomass and bio-energy, water) based on farming, improvement of policy making for developing renewable energies, developing atlas of renewable energies based on farming and improving policy making of developing renewable energies in Ardabil province. According to the results of this study, the most talented town of Ardabil province in terms of renewable energy is Meshgin shahr town. Solar energy 3/449 kW h/m2/y, hydropower 270/34 Gw h/y and geothermal 76/11kw h/y ranked the first among all the cities of Ardabil province. And the lowest was Sarein city.
Solar Thermal Engineering
Mohammed Gwani; Abdullahi Bello Umar; Abubakar Gado Abubakar
Abstract
Traditional cooking methods using fuel woods can pose very serious challenges of local and regional air pollution and land degradation. These methods are inefficient, unsustainable and have serious implications to the environment. To overcome these challenges, a novel four reflectors solar baking oven ...
Read More
Traditional cooking methods using fuel woods can pose very serious challenges of local and regional air pollution and land degradation. These methods are inefficient, unsustainable and have serious implications to the environment. To overcome these challenges, a novel four reflectors solar baking oven has been designed and tested for application in rural areas. The solar baking oven consists of four reflectors made from plane mirrors which reflect the Sun’s rays to the absorber plate placed at the baking chamber. The four reflectors intensify the incoming solar radiation into the baking chamber and increase the thermal properties and efficiency of the oven thereby resulting in shorter cooking time. The result obtained from the study showed that the oven can attain high temperature values. The temperature values are higher when the oven is loaded compared to when the oven is unloaded. When the oven is unloaded, the highest temperature attained by the four reflector solar baking oven is 128.6oC at 13:00 pm, as compared to 133oC at 13:00 pm, when the oven is loaded.
Fuel Cells
M. Rostami; A. H. Farajollahi; F. Bagherpor; V. Sfandiyar
Abstract
Polymer electrolyte membrane fuel cells (PEMFCs) produce high power density efficiently and in a pollution-free way. Therefore, it is employed in UAVs. Flow fields play key role in the performance of PEMFC-powered UAVs. In this study, a novel flow field named modified combined was introduced and investigated ...
Read More
Polymer electrolyte membrane fuel cells (PEMFCs) produce high power density efficiently and in a pollution-free way. Therefore, it is employed in UAVs. Flow fields play key role in the performance of PEMFC-powered UAVs. In this study, a novel flow field named modified combined was introduced and investigated by a three-dimensional and two-phase PEMFC model. In the flow field main channels are tapered aiming to reinforce the performance. The study consists of two steps. In the first stage, modified combined was compared with parallel, serpentine, interdigitated, and combined. The results showed that in the modified combined compared with simple combined, pressure drop decreased 22.6%. Modified combined demonstrated suitable oxygen distribution and appropriate management and the specific power of modified combined is the highest value among all flow fields. Finally, the effect of atmospheric conditions on the performance of the PEMFC with modified combined flow field was studied and two equations were presented to predict the performance at 0.4V and 0.7V at the different altitudes of flight. The findings unveiled the point that in the cruise phase of the flight, low voltage is more suitable for PEMFC-driven UAV with modified combined flow field. All in all, modified combined flow field and low voltage are recommended to be utilized in PEMFCs as propulsion system of UAVs.
Ravinder Kumar; Anand K. Bewoor; R. Alayi
Abstract
India’s rapid economic growth and change in lifestyle have increased the level of municipal solid waste (MSW) generation in the country. Metropolitan cities in India are contributing a major portion (in lakhs metric tons per day) of MSW. It is only due to the lack of availability of poor infrastructure ...
Read More
India’s rapid economic growth and change in lifestyle have increased the level of municipal solid waste (MSW) generation in the country. Metropolitan cities in India are contributing a major portion (in lakhs metric tons per day) of MSW. It is only due to the lack of availability of poor infrastructure to handle MSW in the country. Also, the people ignorance towards to handle these waste is also a big challenge to handle this problem. The implementations of low-cost and user-friendly methods are the primary need to handle this kind of situation. It can be easily predicted that Kitchen waste (KW) is contributing a major portion in MSW and its ignorance towards disposing off is increasing environmental pollution day-by-day. It is the motivation of the present study and a comprehensive review of KW generation in India has been done. A study based on prefeasibility to handle KW is also done and based on that a feasible solution is provided to handle KW on waste to energy for sustainable new business investment opportunities in the present work. The proposed plan will not only reduce the level of MSW in the country but will also create a lot of opportunity for employment in the country for a future generation. The present work concludes that installation of this kind of pilot project in metropolitan cities is the present need for the development of the recycling industry sector using KW as a raw material in India.
Wind Energy
M. Ahmadi; S.A.A. Mirjalily; Seyed A. A. Oloomi
Abstract
This study applies an appropriate turbulence model to simulate the wind distribution in a 3D urban area around a tall building as a bluff body which is one of the most important research topics due to the increasing concerns about human health risks due to air pollution in recent decades. Hybrid RANS/LES ...
Read More
This study applies an appropriate turbulence model to simulate the wind distribution in a 3D urban area around a tall building as a bluff body which is one of the most important research topics due to the increasing concerns about human health risks due to air pollution in recent decades. Hybrid RANS/LES approach, was used to reduce computation time while maintaining computational accuracy. On the other hand, since no homogeneous direction exists in the flow in the Hybrid (RANS-LES) approach, the LES and Smagorinsky Sub Grid-Scale (SGS) approach are implemented with the standard k-ε turbulence model as RANS. To obtain more accurate results, the second-order Van Leer Method (VLM) was employed in advection terms. The sensitivity study of the input parameters shows that the intensity of the input turbulence has a significant effect on the surface pressure fluctuations. The results of velocity and pressure distribution showed a very close agreement to wind tunnel experimental data. Finally, the effects of the inflow characteristics on the peak pressure on the lateral sides is also studied. As the results, fluctuation pressure distribution was strongly dependent on the turbulence of the flow.
Solar Thermal Engineering
Seyed Younes Afshoon; Rouzbeh Shafaghat; Mofid Gorji Bandpy
Abstract
This paper investigates the melting behavior of phase-change material (PCM) in an evacuated tube solar collector. The outer tube was made of borosilicate glass with a diameter of 60 mm, and the inner tube was made of copper with a diameter of 10 mm and length of 1500 mm. The heat transfer problem in ...
Read More
This paper investigates the melting behavior of phase-change material (PCM) in an evacuated tube solar collector. The outer tube was made of borosilicate glass with a diameter of 60 mm, and the inner tube was made of copper with a diameter of 10 mm and length of 1500 mm. The heat transfer problem in heat pipe was investigated in four cases: finless, full fin, half fin, and third fin. The fins were cut from a 35 mm diameter copper tube and installed concentrically with the outer tube. The inner space between the absorber tube and the heat pipe was filled with stearic acid as the PCM. The numerical simulation was conducted using the Ansys Fluent 2022 for the laminar incompressible Newtonian fluid flow in the transient state via the enthalpy-porosity model. The initial temperature of PCM was 27°C, and liquid fraction was zero at the beginning of the simulation. After validating the numerical results with experimental ones, the collector performance was evaluated by considering the four temperatures of 68, 72, 76, and 80°C for the fin and heat pipe at three different times t = 22, 55, and 110 s. The results showed that by increasing the fin area in three cases of third fin, half fin, and full fin, the melting and storage time of PCM were reduced by 6%, 44%, and 87%, respectively. Also, as the Estefan number increased from 0.007 to 0.05, 0.09, and 0.13, the process of PCM melting decreased by 75%, 85%, and 92%, respectively.
S. Jafarian; E. Sarkardehee; D. Monsefi Parapari; M.R. Mojahedi
Abstract
In urban open spaces, especially in large cities with warm climates, users are experiencing high thermal loads, which causes thermal discomfort. Thermal comfort in open spaces can be improved; by shading. The problem is shading and protecting open spaces from stresses caused by overheating of the earth's ...
Read More
In urban open spaces, especially in large cities with warm climates, users are experiencing high thermal loads, which causes thermal discomfort. Thermal comfort in open spaces can be improved; by shading. The problem is shading and protecting open spaces from stresses caused by overheating of the earth's surface and environment. The importance of shade and reducing radiation in achieving thermal comfort in open urban spaces is to increase human presence, create climate change, increase comfort conditions. Recognizing factors that create shadows, such as canopies and their characteristics, can create a favorable space to enjoy the capabilities of outdoor space. New membranes have many characteristics of nomadic tents, and, due to creating shade and natural ventilation, are very suitable for areas with hot climates. Introducing an optimal model and dimensions of a lightweight membrane canopy can create outdoor thermal comfort and increase the efficiency of outdoor spaces. In this paper, library, field, and simulation studies have been used. According to field studies, the presence of membrane canopy can cause temperature differences up to 7.8 C. The simulation results with Ansys, ENVI-met, and Ladybug showed that the membrane canopy cools the space below and prevents overheating. Between four canopy models, the saddle canopy is suitable with a 40.63% impact on the environment and creates cooler space under the canopy. Therefore, a lightweight saddle membrane canopy with dimensions of 5*5 m^2 and a useful height of 3 meters is introduced as a suitable model of membrane canopy for the hot climate of Semnan.
Solar Thermal Engineering
A.R. Shateri; I. Pishkar; Sh. Mohammad Beigi
Abstract
Trombe walls and solar chimneys have been widely used by the construction industry for many years to heat buildings. In this study, the heat conductance of a Trombe wall was simulated and studied. The equations related to energy and momentum were solved numerically by use of the technique of control ...
Read More
Trombe walls and solar chimneys have been widely used by the construction industry for many years to heat buildings. In this study, the heat conductance of a Trombe wall was simulated and studied. The equations related to energy and momentum were solved numerically by use of the technique of control volume. The equations were solved simultaneously using the Simple algorithm. At first, a base case was defined and simulated. A sensitivity analysis study was then performed to investigate the parameters affecting the performance of the wall. Based on the results, an optimized geometry was suggested which maximized the performance of the Trombe wall. In addition, the effect of the presence of the fins on the surface of the absorber wall was studied. In order to obtain the best geometry, the fins were assumed to have different shapes but a constant area. The results showed that the Trombe wall with rectangular fins demonstrated the best performance compared to the other fin geometries studied in this paper. The presence of rectangular fins can increase the room temperature by 1.24% compared to other fin geometries.
Energy Policy
M. Ansari Manesh; E. Sarkardehee; S. Jafarian
Abstract
Human beings spend most of their time in indoor environments. A large part of people around the world work and live in urban areas. Economic productivity is an important goal of different buildings, especially office buildings. Various factors play a role in economic productivity, including reducing ...
Read More
Human beings spend most of their time in indoor environments. A large part of people around the world work and live in urban areas. Economic productivity is an important goal of different buildings, especially office buildings. Various factors play a role in economic productivity, including reducing energy consumption, managerial programs, and increasing the personnel’s efficacy. Increasing attention to efficiency see day by day. Efficiency is a dependent variable i.e., it depends on the individual, environmental, and work conditions. In recent years, most offices pay attention to indoor environmental quality. Because the cost of hiring staff is higher than the cost of operating and maintaining a building. Thus, spending on improving the workplace is the most effective strategy to improve efficiency. This research seeks to study the effective factors on the efficiency of the employees through field studies. Environmental measurements of temperature, humidity, and carbon dioxide were measured in office buildings (from February 4, 2012, to March 5, 2012). Physical measurements showed that, as these parameters increased, efficiency decreased.Then employees fill out the questionnaires (N=328) in the offices of Kermanshah city. An indoor environment is effective for public health. Having healthy indoor environments is a definite right of people. The results of this research showed that satisfaction with the thermal condition, thermal comfort, optimal thermal condition, suitable workplace, and high quality of the workplace are factors influencing efficiency. Providing desired thermal conditions and increasing the quality of the workplace have the highest and lowest effects on the efficiency of employees.
Systems with Low Energy Consumption
Ahmadreza Keshtkar Ghalati; Mahdieh Ahmadian
Abstract
Light shelves not only create shade but also improve the uniformity of daylight. In addition to saving energy, they can improve the lighting quality of a space. This research aims to position light shelves and deep windows to enhance energy efficiency and daylight illuminance in classrooms in Abadan ...
Read More
Light shelves not only create shade but also improve the uniformity of daylight. In addition to saving energy, they can improve the lighting quality of a space. This research aims to position light shelves and deep windows to enhance energy efficiency and daylight illuminance in classrooms in Abadan (Iran) with hot and dry climates. Rhino/Grasshopper software and Ladybug/Honeybee plugins were used to model and evaluate visual comfort and EUI. By comparing the types of external, internal, and central shelves and in different situations of window depth, the following results were obtained: By combined use of light shelves and deep windows: In central light shelves, energy consumption decreased by 20%, and glare effects were reduced by 53.37%. As a result, installing a window in the depth of the wall did not have much effect on reducing energy consumption, but to some extent, it controlled the intensity of glare. The deep window has reduced energy consumption (13%), and using light shelves has improved energy performance (14 to 20%). Compared to the base model, the combined light shelves reduced UDI by 20% and glare by 53%, while the inside light shelves reduced UDI by 14% and glare by 30%. Therefore, installing light shelves always reduces glare. But if the intention is to save energy, the central and external light shelves in the position of the deep window are very useful.
W. Rahimy; Gh. J. Laame; E. Acikkalp; S. Yerel Kandemir
Abstract
Due to the increasing population growth and energy need, interest in renewable energy sources has increased in recent years. Biogas is one of the sustainable energy resources in the world. In cattle, ovine, and poultry farming, a large amount of fertilizer is produced in Afghanistan. These wastes are ...
Read More
Due to the increasing population growth and energy need, interest in renewable energy sources has increased in recent years. Biogas is one of the sustainable energy resources in the world. In cattle, ovine, and poultry farming, a large amount of fertilizer is produced in Afghanistan. These wastes are a big problem for businesses, and their evaluation is of great importance. One of the ways to utilize wastes is biogas production. In this study, the annual biogas and total annual heat value potential of Afghanistan, depending on the number of animals, were determined. As a result, Afghanistan's biogas potential between 2010 and 2017 is between 1172355870 m3/y and 1282692614 m3/y. It has been determined that the total annual heat value potential is between 29117122340 MJ / y and 26612478246 MJ /y. As a result, it was seen in this study that the widespread use of biogas in Afghanistan is of great importance in terms of both waste disposal and energy production
Systems with Low Energy Consumption
Seyed E. Hoseini; M. Simab; B. Bahmani-Firouzi
Abstract
The argument of power systems planning in home microgrids has become one of the burning topics in optimization studies today among the researchers. Since the installation and use of high-capacity energy sources in power systems have many limitations and constraints, so part of the perspective of power ...
Read More
The argument of power systems planning in home microgrids has become one of the burning topics in optimization studies today among the researchers. Since the installation and use of high-capacity energy sources in power systems have many limitations and constraints, so part of the perspective of power systems studies tends to operate residential microgrids. For this purpose, in this paper, operation planning is based on a residential microgrid consisting of combined heat and power (CHP), heat storage tank and boiler, and when possible, surplus electricity is sold to the upstream network to generate revenue. One of the innovations of this paper is the use of the exergy function to complete the optimization and, in practice, combine energy with economics. Other objective functions of this paper are to discuss the reduction of carbon dioxide in the air and the cost of operation. Energy management and planning in this home microgrid is tested with different capacities and types of CHPs, so that the home operator can choose the best mode to use. The multi-stage decision based dynamic programing (MSD-DP) optimization approach is used to minimize the operation costs of proposed framework. The most important innovation of this paper is the use of exergy function for energy management in a residential complex where CHP can also be used to generate electricity and heat simultaneously. Therefore, determining the capacity of CHP and the possibility of exchanging electricity with the upstream network can be mentioned as other innovations of this research.
Energy Policy
M. Mohamadi Janaki; M. A. Sobhanallahi; A.R. Arshadi Khamseh
Abstract
The trend of the fourth industrial revolution in the field of energy, like other sectors, indicates that the path of production, development and approaches to energy use in the world is changing every day. This change can be seen in the growth of new energy production in developed countries by renewable ...
Read More
The trend of the fourth industrial revolution in the field of energy, like other sectors, indicates that the path of production, development and approaches to energy use in the world is changing every day. This change can be seen in the growth of new energy production in developed countries by renewable energy. Owing to the global energy crisis all around the world and the exhaustible non-renewable energy resources, as well as increasing the pollution and green supply chain due to the indiscriminate use of fossil fuels, the need to use sustainable energy, especially In the industrial sector, which accounts for 40% of energy consumption in our country, has been paid attention to. The present study developed and prioritized green supply chain strategies with uncertainty over time under fuzzy conditions in Mobarakeh Steel Company. First, the internal strengths, weaknesses, opportunities, and threats were identified based on theoretical foundations and experts’ opinion. Then, the green supply chain strategies of Mobarakeh Steel Company were developed using the SWOT method. Fuzzy ANP method was used for weighing the dimensions of sustainability while the TOPSIS and TODIM methods were used for weighing the strategies. The results indicated that among the indicators of sustainability, "social" indicator had the first rank, "environmental" indicator had the second rank, and "economic" indicator had the third rank. In addition, SO strategies had the first rank, ST strategies had the second rank, WO strategies had the third rank, WT strategies had the fourth rank.
H. Alm ElDin Mohamad; E. Medhat; ElSamadony M.; R. Mohamed; M. Muthu
Abstract
Due to traditional energy resources problems, scientists looked for a new concept to face these problems. The Solar chimney is one of the promising concepts in renewable energy technology that needs performance enhancement, the proposed study aims at assessing the remarkable advances in the understanding ...
Read More
Due to traditional energy resources problems, scientists looked for a new concept to face these problems. The Solar chimney is one of the promising concepts in renewable energy technology that needs performance enhancement, the proposed study aims at assessing the remarkable advances in the understanding of solar chimney power plant (SCPP) performance investigation through extensive studies with different focuses on several aspects of SCPP technology. In this scientific review paper solar chimneys based on the historical review, enhancements, working principle, components and effective factors, advantages and disadvantages.
Electricity Generation by Green Energy Sources
Reza Alayi; Salam ollah Mohammadi-Aylar
Abstract
Today, policymakers are aware of the substantial advantages of renewable energies. From the point of view of national and regional decision-makers, the first priority of preparing a com-prehensive energy plan and the second priority of determining the share of renewable energy in the total energy production ...
Read More
Today, policymakers are aware of the substantial advantages of renewable energies. From the point of view of national and regional decision-makers, the first priority of preparing a com-prehensive energy plan and the second priority of determining the share of renewable energy in the total energy production basket of the country is an essential step in the energy policy pro-cess. In choosing from various renewable energy options, environmental dimensions are com-bined with economic, technical, and social criteria, which shows the need to combine these crite-ria, the multi-criteria of the governing decision-making space, and policy-making. Multi-criteria decision-making techniques can play an important role in choosing the best solution and option. The statistical population of this study is eight cities in the case study. The renewable energy sources studied include wind, solar, water, geothermal, and biomass. First, the potential of re-newable energy for the study areas was identified. Then the two main criteria of sustainable de-velopment: economic criteria with 5 sub-criteria and environmental criteria with 3 sub-criteria were analyzed. Finally, using the Economic Analytic Network Process (ANP) sub criterion, the environmental sub-criterion of each of the weighted renewable energies was allocated. One of the essential results of this research is the income of 72868.8 $ from solar power in Ardabil. The cost of energy is $ 2.72 kWh. The lowest cost per unit of energy produced is related to Khalkhal geothermal energy at $ 0.144.
M. Taghavi; H. Salarian; B. Ghorbani
Abstract
The present study economically evaluates a combined hydrogen liquefaction configuration using combined heat and power system, photovoltaic cells unit and liquid air energy recovery for precooling under climatic states of Yazd, Iran. The LAC recovery is used to precool hydrogen. Moreover, the cascade ...
Read More
The present study economically evaluates a combined hydrogen liquefaction configuration using combined heat and power system, photovoltaic cells unit and liquid air energy recovery for precooling under climatic states of Yazd, Iran. The LAC recovery is used to precool hydrogen. Moreover, the cascade refrigeration systems with helium and hydrogen refrigerants are employed to supply refrigeration and liquefaction. The rest of the power required for refrigeration cycles to liquefy hydrogen is supplied by PVC unit. This integrated structure generates liquid hydrogen by receiving 5559 kW of power from PVC unit, 60.79 kg/h of natural gas, 8000 kg/h of liquid air and 1028 kg/h of gaseous hydrogen as inputs. The annualized cost of the configuration is applied to economically evaluate the hydrogen liquefaction system using renewable energies. The developed integrated structure is economically evaluated by HYSYS V10 software and m-file code in the MATLAB package. The economic research results of the hybrid cycle indicate the period of return, prime price of liquid hydrogen production and additive value are 4.249 years, 5.432 USD/kg LH2 and 1.567 USD/kg LH2, respectively. The economic sensitivity examination of the combined system reveals POR increases from 2.295 to 13.97 years and net annual profit decreases from 32.66 to 5.366 MMUSD/year by increasing the gaseous hydrogen cost from 1.4 to 3.4 USD/kg LH2. Moreover, POR increases from 2.753 to 25.07 years and levelized cost of product increases from 5.02 to 7.488 US$/kg LH2 by increasing the capital cost from 52.5 to 217.5 MMUSD.
G. Jafar Laame; W. Rahimy; S. Yerel Kandemir; E. Acikkalp
Abstract
Energy is an essential need for living, and renewable energy sources are increasingly popular sustainable energy sources. Solar energy is an inexhaustible and clean, sustainable energy source in the world. In this study, heating of a greenhouse in Herat (Afghanistan) with a heat pump using solar energy ...
Read More
Energy is an essential need for living, and renewable energy sources are increasingly popular sustainable energy sources. Solar energy is an inexhaustible and clean, sustainable energy source in the world. In this study, heating of a greenhouse in Herat (Afghanistan) with a heat pump using solar energy was investigated. The greenhouse was kept at 20 oC, and the electricity required to operate the heat pump was taken from the grid. As a result of the analysis, the exergy/electricity input reaches 25.59 kWh, while the minimum values are equal to 0.01 kWh. It was determined that the product exergy went maximum product exergy of 6.38 kWh. Finally, it was determined that a ground source heat pump with a higher COP could be used instead of an air source heat pump.
Electricity Generation by Green Energy Sources
A.H. Bolurian; H.R. Akbari; T. Daemi; S.A.A. Mirjalily; S. Mousavi
Abstract
This paper proposes an integrated energy management system for grid-connected microgrids, taking into account the demand response programs, fossil fuel-based generators, renewable energy sources and energy storage systems. In the proposed approach, the constraints of the problem are considered jointly ...
Read More
This paper proposes an integrated energy management system for grid-connected microgrids, taking into account the demand response programs, fossil fuel-based generators, renewable energy sources and energy storage systems. In the proposed approach, the constraints of the problem are considered jointly in the model of the energy management systems and are used for microgrid energy management planning and economic dispatch. One of the innovations of this paper is to use the Internet of Things (IoT) platform to adjust the maximum ramp rate of production units in microgrid due to the limitations of production capacity. Since the system considered, models the general state of the internet communication of objects without the need to access the communication channel, so that the energy of consumers should be minimized as second objective function.in this platform, whenever one of the objects has a message to send, it sends it without the need to reserve a resource and schedule. The IoT can establish a good relationship between power producers in a way that reduces operating costs by exchanging data. Optimization of energy consumption in the hybrid power grid studied in this paper shows that the use of IoT platform can reduce the transmission line losses in addition to operating costs. The output results of using data in the IoT context and comparing it with the traditional mode represent the superiority of the proposed approach.
Solar Thermal Engineering
Selfa Johnson Zwalnan; Nanchen Nimyel Caleb; Peter Muar Kamtu; Pahalson Cornelius Dawap
Abstract
This research proposes and evaluates an enhanced open-loop photovoltaic evacuated tube solar thermal collector hybrid energy system based on the developed multi-objective energy management strategy that manages and coordinates the hybrid system with a randomly unreliable grid power source to meet the ...
Read More
This research proposes and evaluates an enhanced open-loop photovoltaic evacuated tube solar thermal collector hybrid energy system based on the developed multi-objective energy management strategy that manages and coordinates the hybrid system with a randomly unreliable grid power source to meet the health center's energy demand using TRNSYS software. A technical assessment of the system shows that the system is capable of meeting system load with a solar fraction of 67% even on days with an overcast sky level of radiation as low as 250 W/m2 and only 37.5% grid power availability. Overall, the system has a solar fraction of 80%. The implication of an 80% solar fraction is the large environmental benefit of reducing emissions and improved system economic viability, indicating that the formulated energy management achieves the goal of promoting renewable energy sources in the hybrid system. An economic analysis of the system revealed that it has a payback period of 6.9 years and Net Present Value of $36,985 at the end of the project's lifetime. This demonstrates that the upgrade of the traditional hybrid PVT with an evacuated tube collector operated based on the developed energy management strategy has met the goal of minimising emissions with significant environmental and economic savings.
H. Benbouhenni
Abstract
In this paper, a novel switching table (ST) of the twelve sectors direct power command (DPC) strategy of doubly-fed induction generator (DFIG) based dual rotor wind power (DRWP) is proposed using two-level hysteresis controllers for reactive and active power and feedforward neural networks (FNNs) algorithms. ...
Read More
In this paper, a novel switching table (ST) of the twelve sectors direct power command (DPC) strategy of doubly-fed induction generator (DFIG) based dual rotor wind power (DRWP) is proposed using two-level hysteresis controllers for reactive and active power and feedforward neural networks (FNNs) algorithms. This intelligent technique was used to replace the conventional ST in order to reduce rotor flux ripple, active power ripple, total harmonic distortion (THD) of stator voltage, torque and reactive power undulations. The simulation and modeling of the proposed strategy were carried out in Matlab software. The DFIG is tested in association with a DRWP systems. The simulation results show that the DPC with FNN controller (DPC-FNN) reduced the THD value of stator voltage, rotor flux undulation, active/reactive power undulation, and electromagnetic torque ripple compared to conventional DPC strategy. It was found that the current waveform becomes purely sinusoidal with a reduction in the THD rate to 0.64%.
Biomass Energy Sources
G. Jebeso Morketo; M. Fekadu; T. Dajene
Abstract
The present study investigated appropriate tree species for biomass energy utilization by determining trees' dry biomass and fuel value index, taking into account that developing countries rely heavily on fuelwood for energy consumption. In Ethiopia, biomass currently meets more than 89.5% of total energy ...
Read More
The present study investigated appropriate tree species for biomass energy utilization by determining trees' dry biomass and fuel value index, taking into account that developing countries rely heavily on fuelwood for energy consumption. In Ethiopia, biomass currently meets more than 89.5% of total energy consumption. Despite this reliance on biomass, there is a scarcity of fuelwood as well as data on dry biomass potential and fuel value indices of tree species utilized in various parts of the country. This study was done on the selection of trees for fuelwood purposes based on their dry biomass potential and fuel quality characteristics. Five highly performed Eucalyptus tree species were selected and aboveground biomass was measured using the destructive approach, whereas the fuel value index was computed using the effective method with four parameters (Calorific Value, Wood density, Ash content and Moisture content). These parameters were determined following the American Society for Testing and Materials method. Finally, aboveground biomass and carbon content varied from 13.96kg to 87.47kg and 6.03kg to 37.86 kg Tree-1, respectively. The biomass and carbon content of E. globulus and E. viminalis were both high. The maximum fuel value index was 276.34 for E. saligna. The computed fuel characteristics were statistically varied among tree species at (P ≤0.0001). Based on the tree fuel characteristics findings, E. globulus, E. viminalis, and E. saligna were identified as the best fuelwood species and were suggested for future plantations.
Ram Chhavi Sharma
Abstract
Demand of energy is increasing day by day worldwide. Also the use of non-renewable energy resources has created serious problems like global warming and air pollution. At the same time, these resources are fast depleting. So we have to look on renewable energy resources to meet the future energy needs. ...
Read More
Demand of energy is increasing day by day worldwide. Also the use of non-renewable energy resources has created serious problems like global warming and air pollution. At the same time, these resources are fast depleting. So we have to look on renewable energy resources to meet the future energy needs. Geothermal energy resources are very versatile renewable energy resource and have wide range of potential use to fulfill the energy need of society in and around the regions of its availability. The present study critically examines the energy from geothermal resources and scope of its utilization in India. There are about 400 known thermal areas in India, each represented by hot spring. The potential geothermal resources exist all around these hot springs. The temperatures of these springs range from 34°C to 96oC. Based on cation’s and anions study, the water types are mostly NaHCO3Cl, NaCaHCO3Cl, CaMgHCO3 and NaHCO3ClSO4. The geothermal fluids from the shallow wells at Puga have been effectively applied to the refining of borax and sulphur as well as experimental space heating. India’s first power plant to produce estimated output power of 250MW will be setup at Puga. The helium content in the hot gases from Bakreswar geothermal sites varies from 1-3%. Helium exploration field stations were established in the above mentioned sites. The geothermal gradient varies from 0.7-2.5oC/m at Chhumathang geothermal field indicating the powerful geothermal region. There exists great scope to use this versatile resource for electrical as well as non-electrical applications in India.
Energy Policy
A. Aryanfar; A. Gholami; M. Pourgholi; M. Zandi Zandi; A. Khosravi
Abstract
The current work proposed a novel fuzzy-based multi-criteria decision-making method to assess the development potential of wind power plants in a country. Type-2 fuzzy logic was utilized to investigate the simultaneous effects of several technical criteria such as wind conditions, ambient temperature, ...
Read More
The current work proposed a novel fuzzy-based multi-criteria decision-making method to assess the development potential of wind power plants in a country. Type-2 fuzzy logic was utilized to investigate the simultaneous effects of several technical criteria such as wind conditions, ambient temperature, and dust activities in a site. Iran was chosen as the case study, considering the various environmental conditions and the lack of thorough investigations in the country. The proposed method could be easily extended to apply to any region. The related technical data for all the 559 Synoptic meteorological stations in the country were collected and used as the inputs for the proposed method. Applying two-step interviews with local experts and reviewing the literature, the leading indicators and their effectiveness were defined. After developing the fuzzy rules and sets, all the sites were scored and ranked using type-2 fuzzy logic in the proposed method. Based on the final standings, priority tables were provided and the top fifty sites for implementing offshore and onshore wind power plants were introduced. Moreover, primary analysis of the collected data indicated that the provinces with high energy consumption and high PM 2.5 levels are in critical environmental conditions. Thus, these provinces need strict attention and planning for sustainable energy supply using renewable energy systems. Based on the results, several recommendations and suggestions were also mentioned to organize investment resources for a more efficient and proper power plant development as well as future studies.