Renewable Energy Resources and Technologies
Mehdi Jahangiri; Akbar Alidadi Shamsabadi; Hamed Saghaei
Abstract
Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of ...
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Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of a four-member family in 10 provinces in this country. The feasibility analysis was performed by T*SOL Pro 5.5 software, and radiation data were obtained by MeteoSyn software. Results indicated that the most suitable station in terms of using solar water heater was Regina, which supplied 35 % of the total heat load for space heating and sanitary hot water purposes. This accounted for 5074 kWh of heat for space heating (25 % of demand) and 3112 kWh energy for sanitary hot water (94 % of demand) using a 40 m2 solar collector. In addition, results are indicative of an annual amount of saving up to 2080 kg of CO2 in the Regina station and an annual reduction of 984 m3 in natural gas for this station. In conclusion, Canada has a potentially alluring market to utilize solar water heaters for providing sanitary hot water for the residential sector.
Environmental Impacts and Sustainability
Mahdi Pourbafrani; Hossein Ghadamian; Meisam Moghadasi; Masoud Mardani
Abstract
In this research study, a cost-effective and reliable weather station using a microcontroller system containing instruments and sensors for measuring and recording ambient variables was designed, fabricated, and tested. The dataset recorded and stored in the meteorological system can be applied to conduct ...
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In this research study, a cost-effective and reliable weather station using a microcontroller system containing instruments and sensors for measuring and recording ambient variables was designed, fabricated, and tested. The dataset recorded and stored in the meteorological system can be applied to conduct various research in the field of energy and environment, especially in solar systems. Employing a microcontroller system reduces costs and provides special features such as accessing data on the web-based spreadsheets and adding control devices. In this system, meteorological information including solar radiation, air temperature, wind velocity, and air relative humidity is measured and saved in user-defined time intervals such as 30 seconds. The total cost for measuring equipment, sensors, and microcontroller along with a data logger is about 110 USD. To demonstrate the importance of using local meteorological data, in the vicinity of the case studies, the dataset provided by the local weather station was compared with the meteorological data of two nearby national stations for one month. The results revealed that the values reported by the national stations were different from the actual values measured by the local weather station. The deviations for solar radiation, wind velocity, air temperature and humidity values were at least 5, 9, 7%, and more than 100%, respectively.
Rozita Asgari; Farida Iraji Asiabadi; Hadi Radnezhad
Abstract
The anaerobic digestion of organic waste for biogas production can be affected by some variables such as temperature; concentration of the biogas feed solution, bacteria populations, and pressure. This study investigated the effects of thermal pretreatment at 50, 75, and 100 ºC on the biogas produced ...
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The anaerobic digestion of organic waste for biogas production can be affected by some variables such as temperature; concentration of the biogas feed solution, bacteria populations, and pressure. This study investigated the effects of thermal pretreatment at 50, 75, and 100 ºC on the biogas produced by simultaneous anaerobic digestion of cow manure, mushroom waste, and wheat straw at thermophilic temperature. Moreover, the effects of a zeolite on reducing the salinity of the wastewater were evaluated. Cow manure, mushroom waste, and wheat straw were mixed to yield a mixture with an optimum carbon to nitrogen ratio of 20-30 and TS of 25-35%. Each thermal pretreatment was prepared in four replicates and placed in a steam bath with a temperature of 55 ºC. The amount of gas produced by each thermal pretreatment was measured every day for 15 days. On day 15, the electrical conductivity of the produced wastewater was measured and the wastewater was exposed to a modified zeolite. The results showed that the greatest level of biogas was produced by thermal pretreatment at 75 ºC, which gave the biogas yield of 0.197 L/gVS after 15 days observation while, the other thermal pretreatments at 50, and 100 ºC gave the biogas yield 0.147, and 0.169 L/gVS, respectively. The highest amount of biogas was achieved on the third day for every three thermal pretreatments. Moreover, the modified zeolite reduced the wastewater salinity by 25%. These results confirmed that thermal pretreatment at 75 ºC is an effective pretreatment for biogas production improvement from the mixture of cow manure, mushroom waste, and wheat straw, and the modified zeolite could be used for salinity reduction of wastewater discharged from the process.
Renewable Energy Economics, Policies and Planning
Seyed Mohammad Emami Razavi; Mohammad Hossein Jahangir; Soroush Mousavi
Abstract
The renewable energy can be utilized to satisfy the energy demand. Moreover, the solar energy as the most abundant energy resource among renewable energies plays a crucial role to provide the energy demand. The BIPV (building integrated photovoltaics) systems can be considered to supply the required ...
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The renewable energy can be utilized to satisfy the energy demand. Moreover, the solar energy as the most abundant energy resource among renewable energies plays a crucial role to provide the energy demand. The BIPV (building integrated photovoltaics) systems can be considered to supply the required energy demand from renewable sources. The essential advantage of BIPV systems is that they can be utilized as building component such as roof, window, shading systems and building façade and they can generate electricity simultaneously. Even though the photovoltaic technologies have been improved within past few years, however the utilization of the BIPV systems will be considered expensive. For this reason, the payback period calculation is considered a vital parameter in evaluating the BIPV systems. In this study, the overall energy consumption for producing one m2 of a mono-crystalline photovoltaic module is calculated 1334 kWh. Additionally, the photovoltaic module data for three companies were investigated and the annual energy productions for one m2 of each company’s product were obtained. The results showed that the average energy payback time for 270 and 280 watt modules are 5.565 and 5.254 respectively. Moreover, the energy payback time for 290, 325 and 340 watt modules were calculated 4.903, 5.437 and 4.965 respectively.
Renewable Energy Resources and Technologies
Mohammed Ali Sami Mahmood; Sergei Kuzmin
Abstract
Solar Organic Rankine Cycle (SORC) is a successful approach to sustainable development and exploiting clean energy sources. The research aims to improve and evaluate the energy efficiency of the SORC for combined heat and power generation for a residential home under the climatic conditions of Baghdad, ...
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Solar Organic Rankine Cycle (SORC) is a successful approach to sustainable development and exploiting clean energy sources. The research aims to improve and evaluate the energy efficiency of the SORC for combined heat and power generation for a residential home under the climatic conditions of Baghdad, Iraq. Thermoeconomic analysis was carried out for the proposed energy supply system. Refrigerant HFC-245fa was used as a working fluid in a solar organic Rankine cycle, and oil poly alkyl benzene (TLV-330) was suggested as a heat transfer fluid in the solar collector field. Parametric studies for some key parameters were conducted to examine the impact of various operating conditions on energy efficiency. The results showed a significant improvement in energy efficiency. The maximum efficiency of SORC CHPG reached 79.14 % when solar heat source temperatures were in the range of 100 to 150 °C and the solar radiation was at a maximum value of 870 W/m2 at noon on the 15th day of July in Baghdad. The maximum energy produced by SORC CHPG was 472.5 kW when the optimal average value of global solar radiation was 7.5 kWh/m2/day in June. The economic investigations revealed that the payback period of the new energy supply system was 10 years with the positive net present cost when the solar power plant was working 18 h/day.
Advanced Energy Technologies
Hassan Ali Ozgoli
Abstract
Fuel cell-based hybrid cycles that include conventional power generators have been created to modify energy performance and output power. In the present paper, integrated biomass gasification (IBG)-molten carbonate fuel cell (MCFC)-gas turbine (GT) and steam turbine (ST) combined power cycle is introduced ...
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Fuel cell-based hybrid cycles that include conventional power generators have been created to modify energy performance and output power. In the present paper, integrated biomass gasification (IBG)-molten carbonate fuel cell (MCFC)-gas turbine (GT) and steam turbine (ST) combined power cycle is introduced as an innovative technique in terms of sustainable energy. In addition, biomass gasification has been explained and shown able to supply the required fuel to the energy generators to compensate for the consumption consequences of fossil fuels. In this system, a molten carbonate fuel cell generates electricity from syngas produced by biomass gasification. In addition, a gas cleaning process prepares adequate treatment before consumption in the fuel cell. Furthermore, for the justification of this system as a combined heat and power (CHP) cycle, a considerable amount of produced heat in the proposed process generates power in GT and ST bottoming cycles. Due to the energy targeting, modeling and simulation of the presented system were fulfilled by the Cycle-Tempo software, and the results showed about 42 MW output power and total efficiency of around 83 %. Further to that, parametric studies represented the durability of the generated power against ambient temperature variations. Finally, changes in total power and efficiency due to the fluctuation of the moisture content of biomass, pressure ratio, and inlet temperature of GT have also been demonstrated.
Advanced Energy Technologies
Mohammad Sajjad Rostami; Morteza Khashehchi; Payam Zarafshan; Mohammad Hossein Kianmehr; Ehsan Pipelzadeh
Abstract
Capacitive deionization (CDI) is an emerging energy efficient, low-pressure and low-cost intensive desalination process that has recently attracted experts’ attention. The process is to explain that ions (cations and anions) can be separated by a pure electrostatic force imposed by a small bias ...
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Capacitive deionization (CDI) is an emerging energy efficient, low-pressure and low-cost intensive desalination process that has recently attracted experts’ attention. The process is to explain that ions (cations and anions) can be separated by a pure electrostatic force imposed by a small bias potential. Even at a rather low voltage of 1.2 V, desalinated water can be produced. The process can be well operational by a professional cell design. Although various processes have been manufactured before, in this study, membrane was removed and a new unit was designed and manufactured (Using CFD Simulation). In this case, the combination of activated carbon powder (with an effective surface area of 2600 m2 per gram), carbon black, and polyvinyl alcohol with a ratio of 35/35/30 coated on carbon paper as electrode materials was considered for tests. The weight was 1.41 grams for each material, and the thickness was 0.44 mm. CDI system was tested, and the results of charge-discharge cycles, cyclic voltammetry, and impedance spectroscopy were evaluated. It can be implied that there is no need for a strong pump and, also, pressure drop can be reduced due to such a noticeable space between two electrodes. Preliminary experimental results showed high specific capacitance (2.1 Farad) and ultra-high salt adsorption capacity, compared with similar cases.
Olatunda Ajani Oyelaran
Abstract
The effect of storage time on some properties of groundnut shell briquette with 5, 10, 15 and 20% binder (cassava gel) was studied. The briquettes were prepared using a motorized briquetting machine. The moisture content, durability rating, water penetration, calorific value and the ash content were ...
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The effect of storage time on some properties of groundnut shell briquette with 5, 10, 15 and 20% binder (cassava gel) was studied. The briquettes were prepared using a motorized briquetting machine. The moisture content, durability rating, water penetration, calorific value and the ash content were determined after every 30 days for 6 months. The results reveals that the moisture content of briquettes decreases during storage during the hot season, the result also reveals a decrease in the durability rating. However, there is an increase in the water penetration with storage time. There is also an increase in the ash content with storage, and this is believed to be responsible for the decrease in the calorific value of the briquettes with storage. However, briquettes with 15 and 20% binder remained relatively stable after 6 months of storage.
Joseph Pemndje; Adrian Ilinca; Théophile Rufin Tene Fongang; Rene Tchinda
Abstract
This paper determines and compares the cost of energy (COE) of various hybrid systems for several off-grid facilities in North and Far North regions of Cameroon by integrating renewable sources and/or storage with diesel generators. The estimated annual energy production by solar PV systems and wind ...
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This paper determines and compares the cost of energy (COE) of various hybrid systems for several off-grid facilities in North and Far North regions of Cameroon by integrating renewable sources and/or storage with diesel generators. The estimated annual energy production by solar PV systems and wind turbines is also discussed. The aim is to study the application of a high penetration renewable energy system to be used as backup in case of failure of the electrical network. Based on meteorological data provided by NASA, a hybrid system using photovoltaic panels, wind turbine, diesel generator, batteries and converter was designed using HOMER software to supply electricity to these loads. It is shown that the use of renewable energies (wind and photovoltaic), despite the fact that it requires large investments initially, is the most economical, most profitable and least polluting system.
Advanced Energy Technologies
Allen G. Njovana; Wenying Yu; Qiying Shen; Jiarui Li; Yanyan Zhu; Yongsheng Liu
Abstract
This study aims to assess the potential of coupling solar PV power plants with Battery Energy Storage System (BESS) to curtail load-shedding and provide a stable and reliable baseload power generation in Zimbabwe. Data from geographical surveys, power plant proposals, and investment information from ...
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This study aims to assess the potential of coupling solar PV power plants with Battery Energy Storage System (BESS) to curtail load-shedding and provide a stable and reliable baseload power generation in Zimbabwe. Data from geographical surveys, power plant proposals, and investment information from related sources were reviewed and applied accordingly. Areas considered to be of good potential to employ the use of BESS were identified considering such factors as feasibility of PV plants, proximity to transmission lines, the size of a town or neighborhood, and energy demands for BESS Return On Investment (ROI) calculations. Previous studies have proven that 10% of the suitable land for PV systems has the capability to generate thirty times the current power demand of the nation operating even with the least efficiency. In recent years, coupling renewable energy sources with a suitable energy storage system yielded improved performances, giving consumers a reliable, stable, and predictable grid. BESS technologies on the utility scale have improved in recent years, giving more options with improved safety, and decreasing the purchase costs, too.
Isa Nasiri Avanaki; Mohammad Sarvi
Abstract
Maximum Power Point (MPP) tracker has an important role in the performance of fuel cell (FC) systems improvement. Tow parameters which have effect on the Fuel cell output power are temperature and membrane water. So contents make the MPP change by with variations in each parameter. In this paper, a new ...
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Maximum Power Point (MPP) tracker has an important role in the performance of fuel cell (FC) systems improvement. Tow parameters which have effect on the Fuel cell output power are temperature and membrane water. So contents make the MPP change by with variations in each parameter. In this paper, a new maximum power point tracking (MPPT) method for Proton Exchange Membrane (PEM) fuel cell is proposed. This method is based on water cycle algorithm (WCA). In order to show the performance and the accuracy of the proposed method, a system consisting of one Proton Exchange Membrane (PEM) fuel cell, one boost converter, one WCA based MPP tracker and one load is considered. WCA determines voltage corresponding to the maximum power of FC then one PID controller tunes the duty cycle of the boost converter. The performance of the proposed method is compared with three other MPPT methods (Perturb and Observe, Voltage-based MPPT and current-based MPPT). The results show that the proposed MPPT method has a high accuracy and a fast response, they also indicate that the proposed method has the better performance in comparison with the other studied methods.
Renewable Energy Resources and Technologies
Thenmozhia Pitchai; Rekha Babu; Saravanathamizhan Ramanujam; Iyappan Kuttalam
Abstract
Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. ...
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Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. The Kissinger, Flynn Wall Ozawa (FWO), and Kissinger Akahira Sunose (KAS) model-free methods were employed to calculate the kinetic parameters by the use of the data obtained from TGA. The thermal decomposition process shows three basic phases of pyrolysis: removal of moisture content, primary and secondary pyrolysis. The experimental values were compared with the obtained values from FWO and KAS models; implying that the model values were in good agreement with experimental results. The values of kinetic parameters obtained from Kissinger, FWO, and KAS methods are very similar to their average values of 115, 136, and 131 kJmol-1, respectively. Gas Chromatograph-Mass Spectroscopy (GC-MS) analysis of pyrolysis products is obtained, showing that bio-char and bio-oil contain 10 and 15 different compounds, respectively.
Nima Ahmadi; Sajad Rezazadeh; Abdolrahman Dadvand; Iraj Mirzaee
Abstract
A three-dimensional computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both gas distribution flow channels and Membrane Electrode Assembly (MEA) is developed. A set of conservation equation is numerically solved by developing a CFD code based on the finite volume ...
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A three-dimensional computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both gas distribution flow channels and Membrane Electrode Assembly (MEA) is developed. A set of conservation equation is numerically solved by developing a CFD code based on the finite volume technique and SIMPLE algorithm. In this research, some parameters like oxygen consumption, water production, velocity distribution, liquid water activity and the fuel cell performance for conventional cases (base Cases) are presented and compared to those in cases with semicircular prominences. The numerical simulations indicated that prominent gas diffusion layer (GDL) could improve the transport of the species through the porous layers and this leads to increment in fuel cell performance. Hence, prominent gas diffusion layers would result in higher current density. Finally the numerical results for the base Cases were compared with the experimental data, which represented reasonable agreement.
Advanced Energy Technologies
Purna Prakash Kasaraneni; Pavan Kumar Yellapragada Venkata
Abstract
Smart homes are considered to be the subset of smart grids that have gained widespread popularity and significance in the present energy sector. These homes are usually equipped with different kinds of sensors that communicate between appliances and the metering infrastructure to monitor and trace the ...
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Smart homes are considered to be the subset of smart grids that have gained widespread popularity and significance in the present energy sector. These homes are usually equipped with different kinds of sensors that communicate between appliances and the metering infrastructure to monitor and trace the energy consumption details. The smart meters trace the energy consumption data continuously or in a period of intervals as required. Sometimes, these traces will be missed due to errors in communication channels, an unexpected breakdown of networks, malfunctioning of smart meters, etc. This missingness greatly impacts smart home operations such as load estimation and management, energy pricing, optimizing assets, planning, decision making, etc. Moreover, to implement a suitable precautionary measure to eliminate missing of data traces, it is required to understand the past behavior of the data anomalies. Hence, it is essential to comprehend the behavior of missing data in the smart home energy consumption dataset. In this regard, this paper proposes an analytical approach to detect and quantify the missing data instants in all days for all appliances. Using this quantification, the behavior of missing data anomalies is analyzed during the day. For the analysis, a practical smart home energy consumption dataset ‘Tracebase’ is considered. Initially, the existence and the count of missing instants are computed. From this, the appliance ‘MicrowaveOven’ is considered for further analysis as it comprises the highest count of missing instants (84740) in a day when compared to all other appliances. Finally, the proposed analysis reveals that the large number of missing instants is occurring during the daylight period of a day.
Mohammad Ameri; Omid Farhangian Marandi; Behrooz Adelshahian
Abstract
In this manuscript, a solar cavity packed with thermoelectric generator modules is investigated numerically. The hot plate of TEG modules make the inner surface of the cube, and the cold plate is outside of the cavity, under natural convection. The TEG modules are electrically in series. ...
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In this manuscript, a solar cavity packed with thermoelectric generator modules is investigated numerically. The hot plate of TEG modules make the inner surface of the cube, and the cold plate is outside of the cavity, under natural convection. The TEG modules are electrically in series. The solution algorithm using the equations of heat transfer and generated power of TEG modules is developed via MATLAB and simulated under various non-concentrated irradiation levels. The generated power variation in solar thermoelectric cavity shows that as the solar irradiance rises, the generated power increases at a growing rate. The radiation varies from 700 to 1200 W/m2, and the generated power increases from 0.2 mW to 10 mW for side TEGs and up to 30 mW for bottom side TEGs. Studying the effect of aperture size shows that, although the generated power of fully open cavity is 2.25 times higher than generated power in 5×5 cm2 aperture size cavity but its efficiency is 50% lower than small aperture cavity. Heat transfer analysis of cavity depicts the 91% of heat transferred by conduction in cube surfaces and, only 6% and 3% of input energy are lost by re-radiation and convection through the aperture, respectively.
Environmental Impacts and Sustainability
Sepideh Abedia; Fatemeh Razi Astaraiea; Barat Ghobadian; Omid Tavakoli; Hassan Jalili
Abstract
Nowadays, the replacement of renewable energies such as biofuels is one of the main priorities in environmental programming and investments. This study is based on sustainable strategy towards integrating algal biomass generation as a green feedstock with wastewater treatment, CO2 bio-fixation, and bioenergy ...
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Nowadays, the replacement of renewable energies such as biofuels is one of the main priorities in environmental programming and investments. This study is based on sustainable strategy towards integrating algal biomass generation as a green feedstock with wastewater treatment, CO2 bio-fixation, and bioenergy production. Therefore, the performance of Trichormus variabilis in biomass production together with ammonium and phosphate removal from an actual effluent obtained from a mixed wastewater streams has been investigated using two mixing methods under aeration and agitation conditions. Dilutions of 10 %, 20 %, 40 %, 60 %, 90 % and 100 % (v/v) were used for growth evaluation. The results showed that the bubbled air effectively enhances the biomass productivity. However, the agitation system was suggested to cultivate the algae in the wastewater due to the elimination of possible mechanical stimulation stress on cells. Moreover, high pH levels (pH>8) indicated a negative inhibitory effect on growth. Thus, unexpected inhibitory impacts were removed through providing the wastewater dilutions mixed with BG11 culture medium, which contains essential required nutrients, to support the algal growth in the wastewater, adjust pH and remove the mechanical stress induced by bubbling compressed air. The results with respect to investigating the effect of the inoculums and wastewater concentrations on the biomass production suggested that the highest biomass generates with 30 mg.mL-1 inoculum in 40 % mixed wastewater diluted by the BG11 medium having the highest potential in CO2 bio-fixation of 9.19±0.64 g.L-1. The results of the wastewater analysis demonstrated the removal potential of ~43 % and ~75 % for NH4+ and PO43−, respectively. The generated biomass after phycoremediation and CO2 bio-fixation can be effectively utilized in different types of biofuel production.
Renewable Energy Resources and Technologies
Uttam Bista; Bhawana Rayamajhi; Bipasyana Dhungana; Sunil Prasad Lohani
Abstract
Anaerobic digestion is one of the most effective technologies for managing degradable waste, which produces renewable energy and digestate as the byproduct. In this study, sewage sludge (SS), poultry litter (PL), and food waste (FW) were co-digested at ratios (SS:PL:FW 2:1:1) with 8 % total solid content ...
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Anaerobic digestion is one of the most effective technologies for managing degradable waste, which produces renewable energy and digestate as the byproduct. In this study, sewage sludge (SS), poultry litter (PL), and food waste (FW) were co-digested at ratios (SS:PL:FW 2:1:1) with 8 % total solid content at ambient temperature (average 22 °C) and controlled temperature (35 °C) in summer. The synergistic effects of co-digesting substrates enhance the biogas production potential when digested at an optimized ratio. The maximum biogas yield was 688.7 L/kgVSa at the controlled temperature and 462.3 L/kgVSa at ambient temperature. The ambient reactor had a methane composition of 55 %, while the controlled temperature reactor had about 60 %. The results provide approaches to increase biogas production in the anaerobic digestion process through co-digestion and controlled mesophilic temperature. Biogas production from anaerobic co-digestion could significantly transform waste into energy in low-income countries to achieve the objective of clean energy production and environmental sustainability.
Advanced Energy Technologies
Sadegh Safari; Hassan Ali Ozgoli
Abstract
In this paper, an electrochemical model was developed to investigate the performance analysis of a Solid Oxide Fuel Cell (SOFC). The curves of voltage, power, efficiency, and the generated heat of cell have been analyzed to accomplish a set of optimal operating conditions. Further, a sensitivity analysis ...
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In this paper, an electrochemical model was developed to investigate the performance analysis of a Solid Oxide Fuel Cell (SOFC). The curves of voltage, power, efficiency, and the generated heat of cell have been analyzed to accomplish a set of optimal operating conditions. Further, a sensitivity analysis of major parameters that have a remarkable impact on the economy of the SOFC and its residential applications has been conducted. The results illustrate that the current density and cell performance temperature have vital effects on the system efficiency, output power and heat generation of cell of the SOFC. The best system efficiency is approached up to 53.34 % while implementing combined heat and power generation might be further improved up to 86 %. The economic evaluation results indicate that parameters such as overall efficiency, natural gas price and additional produced electricity that has prone to be sold to the national power grid, have a significant impact on the SOFC economy. The results indicate the strong reduction in the purchasing cost of the SOFC, i.e. not more than $2500, and improving the electrical efficiency of SOFC, i.e. not less than 42 %, can be the breakeven points of investment on such systems in residential applications. Also, it is found that the target of this SOFC cogeneration system for residential applications in Iran is relying on considerable technological enhancement of the SOFC, as well as life cycle improvement; improvement in governmental policies; and profound development in infrastructures to mitigate legal constraints.
Siamak Azimi-Nam; Foad Farhani
Abstract
Effects of temperature on electrical parameters of polysilicon solar cells, fabricated using the phosphorous spin-on diffusion technique, have been studied. The current density–voltagecharacteristics of polycrystalline silicon solar cells were measured in dark at different temperaturelevels. For ...
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Effects of temperature on electrical parameters of polysilicon solar cells, fabricated using the phosphorous spin-on diffusion technique, have been studied. The current density–voltagecharacteristics of polycrystalline silicon solar cells were measured in dark at different temperaturelevels. For this purpose, a diode equivalent model was used to obtain saturation current densitiesmeasured at the required temperatures. The experimental results showed that the increase intemperature from 27 to 70˚C produced a rapid increase in the saturation current densities from 0.00003to 0.0005A. The changes in the open circuit voltage and the short circuit current density were found tobe linear with the temperature variations: about 3 mV/˚C reduction in the open circuit voltage wasobserved. Measurements of the short circuit current density revealed a very small dependency of thecurrent density on the temperature variations. Accordingly, the short circuit current density increasedfrom 17.8 to 18.4 mA with increase in temperature from 27 to 107˚C. Measurements of the outputpower versus load resistance were obtained at different temperature levels. The results showed that theoutput power dropped by 30% with temperature rise from 27 to 107˚C.
Sajjad Golshannavaz; Daryoosh Nazarpour
Abstract
Recently, along with the depletion of fossil fuels and growing electrical requirements, more attention has been paid on utilizing Renewable Energy Sources (RESs). The Chichest tourism complex is located 20 km far from Orumieh, Iran which has been supplied through the main distribution grid connection. ...
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Recently, along with the depletion of fossil fuels and growing electrical requirements, more attention has been paid on utilizing Renewable Energy Sources (RESs). The Chichest tourism complex is located 20 km far from Orumieh, Iran which has been supplied through the main distribution grid connection. But, recently the trend is to expand the share of RESs in supplying microgrids demand. Hence, this study reports the optimum investment planning for electrical expansion of grid-connected Chichest tourism complex including diesel/wind/PV/battery technologies. For the optimal planning of microgrid, an efficient simply-computational two-stage procedure is proposed. In the first stage, all of the feasible system configurations are determined using NREL’s HOMER software which is a well-known and well-established optimal modeling environment. Subsequently, in the second stage based on Analytical Hierarchy Process (AHP) and simple additive weighting (SAW) method, the best configurations for hybrid system are determined through the Expert Choice software considering economical and environmental criteria. With the aim of providing a comprehensive decision-making capability, a sensitivity analysis is performed considering relative importance of criteria. Simulation results demonstrate that for Chichest coast, the best configuration is grid/diesel/wind hybrid system as it shows a uniform behavior for different cases.
Renewable Energy Resources and Technologies
Alireza Rastikerdar
Abstract
The municipal solid waste in Landfill is transformed into landfill gas during a biochemical conversion process called bio-degradation. Gas release from landfills has potentially different environmental effects; therefore, assessing and forecasting the rate of production and release of gas from landfill ...
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The municipal solid waste in Landfill is transformed into landfill gas during a biochemical conversion process called bio-degradation. Gas release from landfills has potentially different environmental effects; therefore, assessing and forecasting the rate of production and release of gas from landfill sites is important for designing these sites and for the successful exploitation of gases as energy sources. In this study, by using LandGEM model, in the span of 2018-2037, the amount of gases produced from the municipal landfill of Sirjan, Iran has been predicted. According to the results, the largest amount of landfill gas emission will be in 2038, a year following the last year of disposal of the waste to the landfill. The total amount of produced gas, carbon dioxide, methane, and NMOCs will be 1.219E+05, 8.932E+04, 3.255E+04, and 1.399E+03 tons per year in 2038 for Sirjan. In the next step, the LandGEM outputs were imported into OpenLCA software. The health and environmental effects of landfill gas emissions were evaluated by USEtox and traci method, respectively, in this software. According to the USEtox method, the value of total health effects was obtained as 0.032496 CTUh; in addition, by using the traci method, the most environmental burden falls in the impact categories of global warming, photochemical ozone formation, ecotoxicity, acidification, respiratory effects. By making sound and suitable plans as of this 20-year period and implementing tube in this place, greenhouse gas emissions to the atmosphere can probably be prevented. It is also suggested that landfill gases be used to supply energy to the Sirjan recycling plant.
Mohammad Ahmadzadehtalatapeh
Abstract
Air pre-cooling equipment is normally being employed in air-conditioning systems for pre-cooling the ambient outdoor air to enhance the air-conditioning systems performance. In this study, the potential of a passive water-to-air heat pipe based heat exchanger (HPHEX) for air pre-cooling purpose in air-conditioning ...
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Air pre-cooling equipment is normally being employed in air-conditioning systems for pre-cooling the ambient outdoor air to enhance the air-conditioning systems performance. In this study, the potential of a passive water-to-air heat pipe based heat exchanger (HPHEX) for air pre-cooling purpose in air-conditioning systems for the high cooling load demanding regions of Iran was investigated. To this end, effectiveness-NTU approach was employed to determine the thermal performance of the heat exchanger. Water-to-air HPHEX with different numbers of rows namely two, four, and six was studied to determine the heat transfer characteristics of the heat exchanger. The thermal performance of the water-to-air HPHEX was investigated under different operating conditions in terms of evaporator inlet air and condenser inlet water coil face velocities and temperatures. After determining the thermal performance of the water-to-air HPHEX, the air pre-cooling capability of the water-to-air HPHEX was explored hour-by-hour for the required months of the year by using TRNSYS software. Based on the simulations results, the water-to-air HPHEX shows an acceptable thermal performance under the operating conditions. In addition, studies showed that the water-to-air HPHEX has a significant capability for air pre-cooling, which makes it applicable to be implemented in the air-conditioning systems operating in south of Iran.
Renewable Energy Resources and Technologies
Sameer Hanna Khader; Abdel-Karim Khalid Daud
Abstract
This study proposes a novel approach to fast and direct determination of the Maximum Power Point (MPP) at any value of solar irradiation and cell temperature, without applying further mathematical processing to operate at that point. The current approach aims to reduce algorithm complexity, time consumption ...
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This study proposes a novel approach to fast and direct determination of the Maximum Power Point (MPP) at any value of solar irradiation and cell temperature, without applying further mathematical processing to operate at that point. The current approach aims to reduce algorithm complexity, time consumption during the iteration, and oscillation to reach the point at which the panel generates maximum possible power. For avoiding or eliminating these drawbacks, the chopper duty cycle (D) at which the panel-generated power should be the maximum is determined using the panel datasheet with respect to voltage and power at different irradiation rates (G). Mathematical equations are derived for MPP voltage and power at any value of solar irradiation using the manufacturer Photovoltaic (PV) specification. The simulation results obtained by MATLAB/SIMULINK platform showed that the power had a linear change, while the voltage had a nonlinear one with narrow variations. The yield duty cycle controls the Modified Single Ended Primary Converter (MSEPIC) that regulates the load voltage through a wide range below and above the rated panel voltage. The simulation results showed the fast response of chopper operation with a negligible starting time required by the MPPT algorithm, no duty cycle oscillation, and shorter iteration time. Furthermore, the conducted approach is validated based on the data published in a reputed journal, and the obtained results gave rise to new aspects that helped reduce dependency on conventional MPPT algorithms and, consequently, enhance the system response, efficiency and cost reduction.
Advanced Energy Technologies
Ashkan Zolriasatein; Zahra RajabiMashhadi; Majid Rezaei Abadchi; Nastaran Riahi Noori; Siamak Abyazi
Abstract
The crisis of contamination that leads to the accumulation of dust particles on insulation equipment and electrical insulators has disrupted the electricity grid. Electric discharge on infected insulators in wet conditions is a serious threat to the reliability of the grid, which can lead to grid failure ...
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The crisis of contamination that leads to the accumulation of dust particles on insulation equipment and electrical insulators has disrupted the electricity grid. Electric discharge on infected insulators in wet conditions is a serious threat to the reliability of the grid, which can lead to grid failure and blackout. In this regard, the importance of hydrophobic and dustproof coatings in the electricity industry has increased in recent years. In this paper, silica nanoparticles in the silicon rubber matrix were used to coat ceramic insulators to decrease the environmental impact of dust and moisture on the insulator’s coatings. One of the essential properties of these coatings is their hydrophobicity to prevent possible problems in power transmission. With this regard, nanocomposites were applied to 70 kN insulators and the tests were designed according to the available standards. The performance of these nanocoatings was evaluated by the implementation of electrical, salt fog, and hydrophobicity tests. Finally, the nanocomposite sample containing 3 wt % silica was recognized as the best one.
Mahsa Alimoradi; Mohsen Jahanshahi; Majid Peyravi
Abstract
Treatment of landfill leachate is challenging, due to its characteristics such as age, dumping place, composition and origin of wastes. For this reason, the application of hybrid processes is helpful for complete treatment of contaminants present in the leachates. The addition of membrane operations ...
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Treatment of landfill leachate is challenging, due to its characteristics such as age, dumping place, composition and origin of wastes. For this reason, the application of hybrid processes is helpful for complete treatment of contaminants present in the leachates. The addition of membrane operations to biological treatment technology offers new advantages for this method. For this aim, a bench-scale integrated process based on submerged aerobic MBR has been designed and fabricated. Also, Nanofiltration process as a post-treatment was used to upgrade MBR effluent. The results showed that the submerged UF-MBR system effectively removed biodegradable trace organic compounds with the average removal rate of about 75% at optimum food-to- microorganism (F/M) ratio (BOD basis) of 0.2 gBOD/g.d under a HRT of 24 h. The addition of NF process increased the treatment efficiency up to 98%. The effluent COD was reduced from 3500 mg/l to below 50 mg/l. Further, the effect of PAC addition was studied. NH3 –N, TKN and Heavy metals removal efficiency were obtained 97 ± 2%, 96 ± 2% and 99 ± 2%, respectively.
