Research Note
Renewable Energy Resources and Technologies
Roxana Isabel Bernaola Flores; Carmen Elena Flores Barreda; Diana Carolina Parada Quinayá; Ursula Fabiola Rodríguez Zúñiga
Abstract
Reducing the demand for fossil fuels and the derived products can be achieved through the development of alternative energy sources. This work presents a countrywide study of the energy potential of lignocellulosic biomass sourced from agro-industrial by-products in the country of Peru. Ranking of the ...
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Reducing the demand for fossil fuels and the derived products can be achieved through the development of alternative energy sources. This work presents a countrywide study of the energy potential of lignocellulosic biomass sourced from agro-industrial by-products in the country of Peru. Ranking of the crops that produce the most waste was followed by an energy potential evaluation of carbohydrate conversion and thermochemical conversion. The crops with high calorific values were sugar cane bagasse, wood waste, and coffee husk. The energy potential of the principal lignocellulosic by-products, in terms of tons of oil equivalents per year, resulted from rice straw at 1.45 M, followed by corn residue at 1.13 M and sugar cane residue at 1.10 M. The northern region of Peru generated the highest quantities of rice (straw and husk), banana (husk and rachis), and sugar cane (bagasse and straw) by-products and the southern regions generated the greatest quantities of quinoa residue, all of which could be used as raw materials for biofuels and aggregates for materials. These results indicate that theoretically, this readily available biomass could meet the country's energy demands while promoting sustainability and national energy security.
Research Article
Renewable Energy Resources and Technologies
Farhad Amiri; Mohammad Hassan Moradi
Abstract
In the power system, frequency stability is critical. The wind turbine oscillates (depending on the wind speed) and is of low inertia. Thus, wind turbines face the issue of power system frequency stability. Since the power system's resources are interconnected via communication networks, the presence ...
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In the power system, frequency stability is critical. The wind turbine oscillates (depending on the wind speed) and is of low inertia. Thus, wind turbines face the issue of power system frequency stability. Since the power system's resources are interconnected via communication networks, the presence of time delay also affects the frequency stability of the power system. When a disturbance occurs in the power system due to load or distributed generation sources (wind turbine), it leads to frequency deviations in the power system, exhibiting low damping speed. Although large conventional generators in the power system provide sufficient inertia and reduce frequency deviation, the damping speed of frequency fluctuations is slow, which may be due to time delays between power system resources. In this paper, virtual damping (a proposed method) is used to accelerate the damping of frequency deviations caused by load disturbances, distributed generation source disturbances, and the time delay between power system resources. The results of the proposed method are compared to those obtained using the conventional method in this field, demonstrating the superiority of the proposed method. The proposed method reduced frequency deviations in the power system caused by disturbances and time delays by 67 % (a 67 % improvement over existing methods in this field) and increased the damping speed of the frequency deviations by 62 % (a 62 % improvement over the methods used in this field).
Research Article
Renewable Energy Resources and Technologies
Sapna Kinattinkara; Thangavelu Arumugam; Nandhini Samiappan; Vivek Sivakumar; Sampathkumar Velusamy; Mohanraj Murugesan; Manoj Shanmugamoorthy
Abstract
Increased global energy consumption demands the use of more energy resources, aggravating environmental issues. This study focused on analyzing biogas production from a mixture of cow dung, water hyacinth, and food waste and checking the efficiency of the biogas. The efficiency of biogas production was ...
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Increased global energy consumption demands the use of more energy resources, aggravating environmental issues. This study focused on analyzing biogas production from a mixture of cow dung, water hyacinth, and food waste and checking the efficiency of the biogas. The efficiency of biogas production was tested using two alternative settings in the study. The first setup employs Eichhornia crassipes that have been NaOH-treated and mixed with co-digestion substrates such as cow manure and food waste which have been stored at room temperature for 32 days. The second setup contains five different types of substrates such as L1-cow dung, L2- cow dung: water hyacinth, L3-cow dung: food waste, L4-cow dung: water hyacinth: food waste, and L5-water hyacinth. The properties of the Eichhornia crassipes were studied on several biogas substrates, such as pH, temperature, COD, TOC, and NPK tests, as well as total biogas output and methane percentage. The results of the comparison analysis show that the substrate L4 has a high level of NPK (4.7 %) and a higher amount of COD (137600 mg/l). These characteristics enhance the gas yield and methane percentage (85 %). Overall, the water hyacinth mixed with cow dung and food waste exceeded the other four substrates. The total yield of biogas from the first setup was 8.5 litres, the flammability was tested on the 28th day, and the blue flame was obtained. Water hyacinth was removed from aquatic areas and used as an alternative energy source, hence being environmentally friendly.
Research Article
Renewable Energy Resources and Technologies
Toyese Friday Oyewusi; Gabriel Alebiowu; Elizabeth Funmilayo Aransiola; Ayowumi Rita Soji-Adekunle; Busayo Sunday Adeboye
Abstract
Briquettes from agro-residues have been promoted as a better replacement to firewood and charcoals for heating and cooking in the rural communities. In view of this, a study was carried out to investigate the effect of pretreatment methods on physical properties and heating values of briquettes produced ...
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Briquettes from agro-residues have been promoted as a better replacement to firewood and charcoals for heating and cooking in the rural communities. In view of this, a study was carried out to investigate the effect of pretreatment methods on physical properties and heating values of briquettes produced from corncob. To accomplish this work, the experiment was designed as a 2×3×3×3 completely randomized with three replicates. The parameters are pretreatment methods (carbonized and uncarbonized), binder types (cassava, corn and gelatine), binder concentrations (10, 20, 30%) and compacting pressure (50, 100 and 150 kPa). A charcoal kiln was fabricated to obtain the pretreatment through pyrolysis and a punch and die was also fabricated to enable the briquette densification. The physical properties tested were limited to moisture content (MC), density and compressive strength and were determined using a conventional method. The heating value of the briquettes produced was determined using bomb calorimeter. The results showed that average moisture content ranged between 5.29-6.58% and 12.75-13.72%, mean relaxed density varied from 813-925 kgm-3 and 963-1166 kgm-3, compressive strength ranged between 2.27-5.07 MPa and 5.97-10.12 MPa and heating value ranged between 28.85-32.36 MJkg-1 and 27.58-28.80 MJkg-1 for carbonized and uncarbonized briquettes, respectively. Briquettes produced from carbonized corncob had a better moisture content and heating value, while briquettes produced from uncarbonized corncob had higher density and compressive strength. The study shows that pretreatment methods under different binder types and concentrations and the compacting pressure significantly affected briquette’s physical properties and heating values.
Research Article
Renewable Energy Resources and Technologies
Krishnarao Rajaram Patil
Abstract
The present study aims to develop different strategies for better utilization of oxygenated Diethyl ether and ethanol as supplementary fuels by blending them with biodiesel as the base fuel in CI engines. The used biodiesel used was readily available Karanja Oil Methyl Ester (KOME), its scientific name ...
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The present study aims to develop different strategies for better utilization of oxygenated Diethyl ether and ethanol as supplementary fuels by blending them with biodiesel as the base fuel in CI engines. The used biodiesel used was readily available Karanja Oil Methyl Ester (KOME), its scientific name being Pongamia Pinnata. Initially, 5 %, 10 %, 15 %, and 20 % amounts of ethanol (volume) were mixed with biodiesel. Further, the optimum selected blend BE15 was mixed with 5 %, 10 %, 15 %, and 20 % DEE by volume to make the ternary blend. This DEE-ethanol-biodiesel blend was tested on the same engine under the same conditions. The experimental results exhibited that the DEE-ethanol-biodiesel ternary blend, BE15DE10, mitigated BTE by 8.89 % and the smoke, NOx, and CO emissions by 15.66 %, 50.7 %, and 18.5 %, respectively, compared with neat biodiesel. The HC emission exhibited a slightly increasing trend. The results summarize the trade-off between smoke and NOx reduction using DEE and ethanol oxygenated fuels. The addition of ethanol by 15 % and DEE up to 10 % by volume to biodiesel could be considered the most favorable blend without any significant modifications in the CI engine.
Research Article
Advanced Energy Technologies
Ming Hung Lin; Juin Hung Lin; Mamdouh El Haj Assad; Reza Alayi; Seyed Reza Seyednouri
Abstract
The optimal combination of distributed generation units in recent years has been designed to improve the reliability of distributed generation systems as well as to reduce losses in electrical distribution systems. In this research, the improved Genetic Algorithm has been proposed as a powerful optimization ...
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The optimal combination of distributed generation units in recent years has been designed to improve the reliability of distributed generation systems as well as to reduce losses in electrical distribution systems. In this research, the improved Genetic Algorithm has been proposed as a powerful optimization algorithm for optimizing problem variables. The objective function of this paper includes power loss reduction, hybrid system reliability, voltage profile, optimal size of distributed generation unit, and finally improvement of the construction cost of combined wind and solar power plants. Therefore, the problem variables are subject to reliable load supply and the lowest possible cost during the optimization process. In order to achieve this goal in this study, the IEEE standard 30-bus network is examined. The results of the system simulation show the reduction of total system losses after DG installation compared to the state without DG and the improvement of other variable values in this network. This loss index after installing DG in the desired bus has a reduction of about 200 kWh during the year and has a value equal to 126.42 kWh per year.
Research Article
Renewable Energy Resources and Technologies
Armin Motamed Sadr; Mehran Ameri Mahabadi; ٍٍEbrahim Jahanshahi Javaran
Abstract
In this research, the performance of an asphalt solar air collector was experimentally tested and the daily thermal and exergy efficiencies of the collector were analyzed. The sun's radiant energy is absorbed by asphalt and converted into thermal energy. Then, it is transmitted to aluminum pipes buried ...
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In this research, the performance of an asphalt solar air collector was experimentally tested and the daily thermal and exergy efficiencies of the collector were analyzed. The sun's radiant energy is absorbed by asphalt and converted into thermal energy. Then, it is transmitted to aluminum pipes buried under the asphalt and, finally, to the air passing through the pipes. A suction fan induces the ambient air to the collector. The experimental results show that the daily thermal efficiencies at mass flow rates of 0.007 (kg/s) and 0.014 (kg/s) are 11.98% and 24.10% and daily exergy efficiencies are 0.34% and 0.66%, respectively, showing the increase in daily energy and exergy efficiencies with increasing the air mass flow rate. In addition, results show that as the flow rate increases, the outlet air temperature decreases. The presence of temperature difference between the inlet and outlet of the collector in the last hours of the day, when the sun's radiation is low, indicates that asphalt acts as a thermal energy storage medium.
Research Article
Renewable Energy Economics, Policies and Planning
Vasundhara Sen
Abstract
Despite the falling costs of Renewable Energy (RE), RE adoption in Indian residential households is still at tepid growth rates. With the onset of retail electricity market deregulation in India, the introduction of “green tariffs” for residential households can be effective in resolving ...
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Despite the falling costs of Renewable Energy (RE), RE adoption in Indian residential households is still at tepid growth rates. With the onset of retail electricity market deregulation in India, the introduction of “green tariffs” for residential households can be effective in resolving the issue of low RE adoption. This study investigates the willingness to pay for green tariffs/renewable energy-based electricity contracts using the contingent valuation method. Data collected from 476 Indian residential households are analyzed by the Double-Bounded Dichotomous Choice technique. The results of the conducted maximum Likelihood Estimation (MLE) method reveal the mean willingness to pay 308.52 Rs per household/month for consumption of green power in a premium-paying setting. Results indicate that although households hold positive perception of renewable energy, the willingness to pay is not commensurately high, indicating an attitude-action gap. The study recommends green energy defaults in residential energy contracts, direct marketing of non-use value of RE use (altruistic and bequest) by power supplying utilities, and promoting RE use through RE opinion champions/influencers as measures to enhance RE adoption amongst Indian residential energy consumers.
Research Note
Advanced Energy Technologies
G Njovana Allen; 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.
Research Article
Renewable Energy Resources and Technologies
Gokul Raghavendra Srinivasan; Aditya Mahajan; Rajiv Seth; Rakesh Mahajan
Abstract
The present study aims to explore the role of characterized hydrocarbons in thermally cracked shell liquid in determining its overall fuel properties and combustion characteristics in a CI engine. For this purpose, waste shell liquid was extracted from waste cashew nut shell by means of cold extraction ...
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The present study aims to explore the role of characterized hydrocarbons in thermally cracked shell liquid in determining its overall fuel properties and combustion characteristics in a CI engine. For this purpose, waste shell liquid was extracted from waste cashew nut shell by means of cold extraction technique using a simple electrically operated mechanical screw press, which reported maximum extractable oil content as 17.7%. In addition, it was thermally cracked at 350-400oC using conventional heating for both lab-scale and pilot-scale extraction. Based on its chemical composition, raw shell liquid contained anacardic acid and cardol, while thermally cracked shell liquid had cresol and methyl oleate as their dominant hydrocarbon compounds. Their composition was found to be 51.84%, 33.68%, 43.87%, and 28.49%, respectively. According to their contribution, both cyclic and aromatic as well as linear-chained hydrocarbons exhibited significant effect on the fuel properties of the cracked shell liquid, with carbon atoms contributing to its physical and thermal properties, whereas cyclic and aromatic hydrocarbons enhance its flow characteristics. Next, neat and blend samples of this cracked shell liquid with petro diesel reported higher peak in-cylinder pressure by 5.6% (on average) due to the presence of fatty acid esters, which induced early ignition and provided sufficient time for combustion. Meanwhile, higher emission levels were attributed by both cyclic and aromatic and linear-chained hydrocarbons, citing aromaticity and unsaturation in their molecules, which also resulted in reduced thermal efficiencies by 12.5% (on average), upon accounting for their inferior calorific content. In conclusion, it is evident that hydrocarbons in these treated shell liquids play a significant role in their fuel properties and engine characteristics.
Research Article
Renewable Energy Economics, Policies and Planning
Mohammad Hossein Jahangir; Arash Kargarzadeh; Mohammad Montazeri
Abstract
Industries as one of the main consumers of electricity have high position in releasing large amount of emissions. Using renewable energies to feed factories is not an easy task and they should be economically viable to compete with fossil fuels. The goal of this study is to analyze the possibilities ...
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Industries as one of the main consumers of electricity have high position in releasing large amount of emissions. Using renewable energies to feed factories is not an easy task and they should be economically viable to compete with fossil fuels. The goal of this study is to analyze the possibilities of using energy local area networks in off-grid and on-grid modes in an industrial project by considering and calculating all primary and deferrable loads in details for the first time. The industrial project is sensitive and all possibilities should be considered closely to avoid economic losses. In this case, changes in electrical loads during the project, degradation of components, environmental risks and economic risks of the investment (for each scenario) are considered and determined too. The results of the research indicate that components degradation can cause 24,000 kWh drop in total electricity production at the end of the project and the total biogas consumption increases from 742 kg/yr to 9330 kg/yr. The results also show that the on-gird scenario (solar/battery) with the Net Present Cost of 200,000$ will be an easy and low risk choice for investment but has high environmental risks. On the other hand, the stand-alone scenario (solar/wind /bio/battery) with Net Present Cost of 598,000$ minimize the environmental risks at the expense of high risk of investment. Comparing multi-year mode with the single-year mode at the end of the project, makes the increased accuracy of the techno-economic analysis in terms of optimum system types, emissions and economics clear.
Research Article
Advanced Energy Technologies
Seyed Amir Hassan Bathaei; Masoud Iranmanesh; Hossein Amiri; Hajir Kourki
Abstract
Thermal Energy Storage (TES) for solar thermal systems has attracted great attention because of the intermittent availability of solar energy. In the current paper, new combinations of several Phase Change Materials (PCMs) including a type of paraffin and some mineral compounds like ammonium nitrate ...
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Thermal Energy Storage (TES) for solar thermal systems has attracted great attention because of the intermittent availability of solar energy. In the current paper, new combinations of several Phase Change Materials (PCMs) including a type of paraffin and some mineral compounds like ammonium nitrate and magnesium nitrate hexahydrate were exanimated and their thermo-physical properties were compared. This study targets solar heating systems at different temperature intervals for the TES. Another new approach of this study is to determine the effect of Multi-Wall Carbon Nanotubes (MWCNTs) with two diameters (D) of 8 and 10-20 nm on paraffin's thermophysical property to improve these properties. An innovative method was used to measure Electrical Conductivity (EC) as it is easier to measure than thermal conductivity (K) to study the effect of nanoparticles on PCM behavior. The results showed that the highest values of improvement over paraffin properties were related to 5% nanoparticle additive for both nanoparticle diameters among the percentages studied. The addition of 5 % nanoparticles with 10-20 nm and 8 nm to paraffin at 25 ° C increased heat conductivity by 142% and 156%, respectively. The addition of nanoparticles to paraffin improved EC several times such that a diameter of 8 nm made a 300% increase in EC compared to 10-20 nm.
Research Article
Renewable Energy Resources and Technologies
Abir Hmida; Abdelghafour Lamrani; Mamdouh El Haj Assad; Yashar Aryanfar; Jorge Luis Garcia Alcaraz
Abstract
Around the globe, a 60 % increase in energy demand is predicted to occur by the end of the year 2030 due to the ever-increasing population and development. With a registered temperature up to 50°C in August 2020, which is classified as one of the hottest regions in the world, the demand for cool ...
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Around the globe, a 60 % increase in energy demand is predicted to occur by the end of the year 2030 due to the ever-increasing population and development. With a registered temperature up to 50°C in August 2020, which is classified as one of the hottest regions in the world, the demand for cool temperatures in Gabes-Tunisia to achieve the thermal comfort of people ensuring the product storage has become more and more intense. Removing heat from buildings represents the most extensive energy consumption process. In this paper, an absorption-refrigeration system driven by solar energy is proposed. A parametric simulation model is developed based on the TRNSYS platform. A comparison between different models for global radiation calculation and experimental meteorological data was carried out. It has been proven that the Brinchambaut model seems to be the most convenient in describing the real global radiation, with an error of up to 3.16%. An area of 22 m² of evacuated tube solar collector ensures the proper functioning of the generator and achieves a temperature up to 2°C in the cold room.
Research Article
Advanced Energy Technologies
Zeinab Sabzian-Molaee; Esmaeel Rokrok Rokrok; Meysam Doostizadeh
Abstract
In this study, a novel stochastic planning method is proposed for AC-DC hybrid distribution networks. The proposed approach is based on the graph theory, and the optimal AC-DC structure of the network is selected among the system spanning trees. The presented method is a Mixed Integer Nonlinear Programming ...
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In this study, a novel stochastic planning method is proposed for AC-DC hybrid distribution networks. The proposed approach is based on the graph theory, and the optimal AC-DC structure of the network is selected among the system spanning trees. The presented method is a Mixed Integer Nonlinear Programming (MINLP) problem, which is solved using genetic algorithm. The buses and lines of the network can be either AC or DC to minimize the system investment costs in the master optimization problem. The location and capacity of the Distributed Energy Resources (DERs) as well as the site and size of the Electric Vehicle (EV) charging stations are optimized in the slave problem to minimize the network losses and system costs. The proposed model utilizes Monte Carlo simulation to deal with the stochastic variations of the renewable energy resources power and load demands. Besides, the converter efficiency curve in the proposed planning problem is modeled based on a function of its input current using PLECS software. The proposed approach for network design can be applied to different DG resources and AC-DC loads. The comparison between the simulation results of the proposed approach and the conventional AC planning method demonstrates the efficiency of the proposed model in reducing network losses and system costs
Technical Note
Advanced Energy Technologies
Mohammad Rahimzadeh; Hamid Samadi; Nikta Shams Mohammadi
Abstract
Energy harvesting from ambient vibrations using piezoelectric cantilevers is one of the most popular mechanisms for producing electrical energy. Recently, efforts have been made to improve the performance of energy harvesters. The output voltage dramatically depends on the geometrical and physical parameters ...
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Energy harvesting from ambient vibrations using piezoelectric cantilevers is one of the most popular mechanisms for producing electrical energy. Recently, efforts have been made to improve the performance of energy harvesters. The output voltage dramatically depends on the geometrical and physical parameters of these devices. In addition, improved performance is often achieved by operating at or near the resonance point. So, this paper aims to reduce the natural frequency to match the environmental excitation frequency and increase the harvested energy. For this purpose, different geometrical and physical parameters are studied to determine the impact of each parameter. These parameters include the length, thickness, density, and Young’s modulus of each layer. The beam is considered a unimorph cantilever with rectangular configuration and the study is performed using COMSOL Multiphysics software. The results are compared with those obtained by an analytical approach. The results show that changing the parameters made the natural frequency of the system vary in the range of 20 Hz to 200 Hz and increased the output voltage up to 20 V.
Review Article
Advanced Energy Technologies
Ghazanfar Shahgholian
Abstract
Distributed flexible ac transmission system (D-FACTS) is a light-weight version of FACTS, which it is easily allocated and costs less than flexible ac transmission system (FACTS) devices. They have potential benefits to improve the system stability and improvement in power quality in microgrid (MG). ...
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Distributed flexible ac transmission system (D-FACTS) is a light-weight version of FACTS, which it is easily allocated and costs less than flexible ac transmission system (FACTS) devices. They have potential benefits to improve the system stability and improvement in power quality in microgrid (MG). The integration of distributed energy sources, loads, electrical energy storage devices, and electronic power devices, as well as the operation of microgrids in connected or island-connected modes has expanded their use. It is a small main grid that can generate electricity when disconnected from the main network. In addition, microgrids reduce the high investment costs required to upgrade the network. The application of DFACTS devices for improving the microgrid operation has been investigated by some researches. This paper provides a review of impact and role of various DFACTS devices in the function of microgrids, which has been reported in recent years in various pieces of the literature. DFACTS devices with their properties are described. Finally, a useful reference and framework for the study is provided for future expansion of DFACTS devices so as to improve the performance of the microgrid.
Research Article
Renewable Energy Economics, Policies and Planning
Ritu Jain; Vasundhara Mahajan
Abstract
In this study, energy management of grid-connected Multi-Microgrid (MMG) is performed through joint optimization of the energy and ancillary service market. The test system comprises the IEEE 30 bus system as the main grid and the 16-bus system as an MMG. The MMG is comprised of dispatchable and non-dispatchable ...
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In this study, energy management of grid-connected Multi-Microgrid (MMG) is performed through joint optimization of the energy and ancillary service market. The test system comprises the IEEE 30 bus system as the main grid and the 16-bus system as an MMG. The MMG is comprised of dispatchable and non-dispatchable generation and loads. The non-dispatchable generators are based on renewable energy sources (RES) such as solar and wind. The uncertainty modeling for wind and solar is performed by Weibull and beta probability distribution function. The strategic integration of RES helps MMG deliver both energy and ancillary services to the utility grid. This research aims to reduce the total energy cost while reducing reserve cost by maximizing the use of RES under normal operation and during contingency conditions. It is observed that if MMG is incorporated into the system, then the total generation cost, reserve cost, and power losses are reduced to 0.11%, 0.325%, and 1.201%, respectively, in normal operating conditions. Under contingency, when Generator 5 is out of service and the main grid is operating alone, the total generation cost increased significantly from 22118.92 $ day-1 to 22435.68 $ day-1 and the real power loss increased from 233.35 MW day-1 to 245.11 MW day-1. However, by interconnecting MMG with the main grid, generation cost and power loss get reduced to 22375.60 $ day-1 and 243.35 MW day-1, respectively. It is analyzed that participation of MMG provides techno-economic benefits during normal operation and contingency conditions.
Research Article
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.
Technical Note
Renewable Energy Resources and Technologies
Fatemeh Norouzi; Morteza Hosseinpour; Saeed Talebi
Abstract
In this paper, an industrial dairy farm unit was taken as a case study to carry out the applicable technical assessment for the construction of a biogas plant using a combined heat and power (CHP) unit. A comprehensive sensitivity analysis was applied to examine the effectiveness of the operational parameters ...
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In this paper, an industrial dairy farm unit was taken as a case study to carry out the applicable technical assessment for the construction of a biogas plant using a combined heat and power (CHP) unit. A comprehensive sensitivity analysis was applied to examine the effectiveness of the operational parameters and feed composition in the purity and production rate of biogas. Aspen Plus was used to implement the anaerobic digestion process. The results showed that any increase in the digester’s operational performance and mass rate of feedstock water led to the modification of biomethane content, but dropped in biogas mass flow rate. Moreover, an increase in the mass rate of carbohydrates, protein, and organic load rate (OLR) of feedstock reduces methane composition. Besides, increasing the rate of lipids has raised the rate of methane production and its composition.
Research Article
Renewable Energy Resources and Technologies
Soheil Fathi; Abbas Mahravan
Abstract
In many middle- and high-income countries, existing buildings will occupy the majority of building areas by 2050 and measures are needed to upgrade the mentioned buildings for a sustainable transition. This research proposes a method to mitigate the energy consumption of existing educational buildings ...
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In many middle- and high-income countries, existing buildings will occupy the majority of building areas by 2050 and measures are needed to upgrade the mentioned buildings for a sustainable transition. This research proposes a method to mitigate the energy consumption of existing educational buildings using four energy efficiency measures (EEMs). The proposed method divides simulations into two main parts: simulations with and without using heating, ventilating, and air conditioning (HVAC) systems. Four passive EEMs are used, including window replacement, proposed shading devices, new insulations, and installing a new partition wall for the entrance part of the building. This research uses a simulation-based method to examine the effect of each EEM on the energy consumption of the building using DesignBuilder software. The steps of data collection and modeling in this research include collecting raw data related to the physical characteristics of the building experimentally and creating a basic model. Afterwards, simulation scenarios were defined based on the proposed method, and several simulations were carried out to examine the impact of each EEM on the energy performance of the building. Two environmental parameters of the simulation process, including indoor air temperature (IAT) and relative humidity (RH), were used. The measures reduced the heating and cooling demands in the building by 80.14% and 15.70%, respectively. Moreover, the results indicated that the total energy consumption of the building were reduced by 10.44% after retrofitting measures.
Research Article
Advanced Energy Technologies
Mohammad Rasooli Mavini; Hassan Ali Ozgoli; Sadegh Safari
Abstract
In this study, various configurations design of a Heat Recovery Steam Generator (HRSG) are examined to enhance energy efficiency of a Combined Cycle Power Plant (CCPP). A novel approach is used to investigate ten applicable configurations of a dual pressure Heat Recovery Steam Generator HRSG thoroughly ...
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In this study, various configurations design of a Heat Recovery Steam Generator (HRSG) are examined to enhance energy efficiency of a Combined Cycle Power Plant (CCPP). A novel approach is used to investigate ten applicable configurations of a dual pressure Heat Recovery Steam Generator HRSG thoroughly to explore the best practice models from the energy-conserving considerations. Further, a fuel consumption assessment has been conducted to identify the best performance of the cycle and investigate the minimum pollutants released of each Heat Recovery Steam Generator (HRSG) configuration. The results have revealed that four scenarios among ten, have expressed a considerably better performance regarding; fuel consumption, steam production, energy efficiency, and finally yet importantly environmental considerations. Further, it has been found that in comparison to the conventional configuration, not only the selected scenarios have proved almost four times improvement in the low-pressure steam generation, but also 30% fuel consumption saving in supplementary firing has been achieved which has both economic and environmental benefits. Moreover the carbon dioxide saving potential for the best scenario is 51.37 kgCO2 MWh-1 consequently the environmental benefit of it is calculated about 133,418 $ MWh-1.
Research Article
Environmental Impacts and Sustainability
Mohammad Javad Amiri; Ali Sayyadi
Abstract
The rising temperature of the earth's surface and the formation of heat islands in megacities have become two of the biggest environmental threats. This compound problem affects urban climatology, including urban vegetation and air pollution, human health, and the environment, including the group of ...
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The rising temperature of the earth's surface and the formation of heat islands in megacities have become two of the biggest environmental threats. This compound problem affects urban climatology, including urban vegetation and air pollution, human health, and the environment, including the group of vulnerable members of the society and public health, leading to the growing death rate. Hence, the purpose of this study is to investigate the leading causes of temperature changes and the development of a thermal island in the city of Tehran following the expansion of this metropolis in recent decades. This research uses thermal remote sensing and GIS techniques to analyze information from Landsat satellite images in (TM-ETM-TIRS) sensors from 1984 to 2020. The results of the research indicated that the surface temperature of the city of Tehran during the years 1984 to 1996, 1998 to 2008, and 2010 to 2020 experienced a relative increase in the summer and winter seasons. In the first decade, the average temperature of the green layer was -7, while the temperature of the magenta and red layers were 20 and 25 degrees, respectively. In the second decade, the average temperatures of the green and dark green classes were -1 and 3 while they were 23 and 27 degrees for the magenta and red classes, respectively. In the third decade, the average temperatures of the green and dark green classes were -1 and 3, and thost of the magenta and red layers increased to 28 and 31 degrees, respectively. Furthermore, the analysis of vegetation cover based on the NDVI index pointed to the continuing reduction of vegetation in the studied years. Regarding the direct correlation between the heat island and vegetation and the concentration of the heat island in the city center, further measures must be taken and the vegetation cover should be increased to reduce the heat island. The city center needs to be decentralized as part of the remedy via proper urban design and planning.
Research Article
Renewable Energy Resources and Technologies
Majid Zarezadeh
Abstract
In this study, besides examining the conditions in the coastal region of Bandar Abbas, the feasibility of using Archimedes torsional turbines to produce renewable energy in this region was studied via field measurement and numerical simulation. Through field study and environmental conditions, depth, ...
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In this study, besides examining the conditions in the coastal region of Bandar Abbas, the feasibility of using Archimedes torsional turbines to produce renewable energy in this region was studied via field measurement and numerical simulation. Through field study and environmental conditions, depth, and amount of vessel traffic were measured. Then,the safe depth was calculated. Through field measurement of the current pattern, effective parameters such as salinity, electrical conductivity, and density were measured and in order to develop the results using numerical simulation with ROMS numerical model, the hydrodynamic pattern of the current for the desired area was formed. After reviewing the results through SOLVER program and linear programming method and creating effective constraints in field monitoring, The optimal energy efficiency of Archimedes torsional was turbines investigated for different incline relative to beneath and angular velocities. The results of the research and simulation demonstrated that changing the tilt of the vertical axis of the turbine between the angles of 5 degrees and 15 degrees would lead to a change in the efficiency of the Archimedes turbine. The optimal efficiency value, 75%, was at an angle of 15 degrees, and a turbine rotation speed of 150 rpm is the highest efficiency. This is an acceptable result considering the low slope of the studied area.
Research Article
Renewable Energy Resources and Technologies
Morteza Hosseinpour; Ali Nazari; Mahdi Rezaei
Abstract
In this study, the effect of digestate treatment after anaerobic digestion (AD) process in two scenarios have been analyzed for an industrial diary unit in the United States. The first scenario involves production of liquid fertilizer and compost while the other scenario lacks from such treatment process. ...
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In this study, the effect of digestate treatment after anaerobic digestion (AD) process in two scenarios have been analyzed for an industrial diary unit in the United States. The first scenario involves production of liquid fertilizer and compost while the other scenario lacks from such treatment process. Aspen Plus has been used to simulate the AD process and assessment of general properties of biogas and digestate. The results of technical analysis show insignificant change in the net power production from the CHP unit in scenario 1. The economic analysis, however, indicates the necessity of digestate treatment for AD systems to be profitable. Furthermore, the results of environmental analysis indicate the mitigation of about 93.4 kilotonnes of greenhouse gas (GHG) emissions in scenario 1, while an AD the scenario 2 saves only 12 kilotonnes of GHG emissions. In other words, digestate treatment has a more significant environmental impact than the power production and its profitability from CHP unit. The reason could be attributed to the enormous consumption of energy during production of chemical fertilizers where digestate treatment process (scenario 1) offsets the utilization of chemical fertilizers in agriculture industry.
Research Article
Renewable Energy Economics, Policies and Planning
Zeinab Ghasemi Sangi; Abbas Tarkashvand; Hanieh Sanaeian
Abstract
The height of buildings is one of the main features of urban configuration that affects energy consumption. However, to our knowledge, the complexity of relationships between the height parameters and energy use in urban blocks is poorly understood. In this context, the present study investigates the ...
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The height of buildings is one of the main features of urban configuration that affects energy consumption. However, to our knowledge, the complexity of relationships between the height parameters and energy use in urban blocks is poorly understood. In this context, the present study investigates the effect of the height distribution of buildings located in a residential complex on the energy consumption required for cooling and heating. This research simulates different possible layouts through computational software. For this purpose, first, the density of a residential complex was determined based on the rules and regulations of Tehran city and according to the site dimensions and certain site coverage. Then, the required building density was distributed in different layouts based on their diversity at different heights. The product of this stage involved 7 different layouts in which the height varied from 1 floor to the maximum number calculated in each part of the simulation. In the next step, the annual energy consumption for cooling and heating the complex was calculated for each of these layouts and compared with each other. The parametric generative model was created in the Grasshopper plugin from Rhino software, and the energy consumption was evaluated with the Honeybee plugin over one year. Also, the research findings were validated through DesignBuilder software using the EnergyPlus engine. The results of the energy simulation indicate that the height distribution of the blocks can have a significant effect on energy consumption. In the optimal case, proper layout reduces the annual cooling and heating energy consumption by 28% and 13%, respectively. Therefore, achieving an optimal value for each of the cooling and heating loads depends on the specific priorities and conditions of the design project. If the design project's priority is to reduce heating energy consumption, increasing the height and distributing the floors evenly between the blocks is a better answer. However, if the priority is to mitigate cooling energy consumption, the optimal layout can include low-rise blocks and a single very high-rise block.
Research Article
Renewable Energy Resources and Technologies
Payam Ghorbannezhad; Behnam Dehbandi; Imtiaz Ali
Abstract
Furandicarboxylic acid (FDCA) is recognized as a valuable product of hydroxymethylfurfural (HMF) derived from cellulosic materials as an abundant renewable source. It could find future bioplastic application if a feasible separation process is developed. To find a commercially available solvent, FDCA ...
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Furandicarboxylic acid (FDCA) is recognized as a valuable product of hydroxymethylfurfural (HMF) derived from cellulosic materials as an abundant renewable source. It could find future bioplastic application if a feasible separation process is developed. To find a commercially available solvent, FDCA should be selectively separated from HMF and the downstream process be supported by pyrolysis-gas chromatography-mass spectrometry experiments in line with density functional theory (DFT). Evaluation of the sigma potential and sigma surface analysis demonstrated that benzene and ethyl acetate enjoyed better extraction and HMF selectivity, whereas FDCA exhibited ideal behavior in the presence of DMF and DMSO solvents. It was proved that the hydrophobicity could be changed by improving the hydrogen-bonding interaction between them. Moreover, the up-down selection of classes of solvents based on the experimental data found by GC-MS revealed that polar molecular solvents (ethanol-water) were more compatible with carboxylic acids and alcohol compounds, while n-hexane was a desirable solvent for phenolic compounds. It was found that levoglucosan retained a significant fraction of water compared to other solvents, which need to be considered for further economic and environmental analysis under the multifaceted framework of biomass-derived products.
Research Article
Renewable Energy Economics, Policies and Planning
Nur Aini; Widi Hastomo; Ratna Yulika Go
Abstract
The percentage of production and utilization of hydrocarbon resources from the livestock sector has raised concerns regarding the worldwide issue of global warming. A total CH4 emissions 78.3% from enteric fermentation and waste management. Meanwhile, N2O emissions are 75–80% of total agricultural ...
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The percentage of production and utilization of hydrocarbon resources from the livestock sector has raised concerns regarding the worldwide issue of global warming. A total CH4 emissions 78.3% from enteric fermentation and waste management. Meanwhile, N2O emissions are 75–80% of total agricultural emissions. This raises questions about the extent of global warming due to increased CO2 resulting in changes in weather and global warming. This research is aimed to predict Green House Gas (GHG) emissions from manure management and present policy alternatives for Indonesian livestock development. Secondary data is taken from fao.org with coverage throughout Indonesia from 1961 to 2021, containing 12,480 rows and 5 column features; item, Element, Year, Unit, and Value emission. LSTM and GRU are used to predict emission trends from manure management to provide alternative policies for greenhouse gas mitigation in Indonesia. The results showed that from a total of 15 types of livestock that emit GHG emissions, 3 types of livestock produce the highest emissions from 1961 to 2021: (a) Cattle, (b) Cattle, and non-dairy (c) Poultry birds. Significant reductions in carbon dioxide equivalent(CO2eq) emissions in 2020 are indicated by reduced public consumption, and hampered supply chains with large-scale social restrictions (covid-19 pandemic policy). Based on these results. the policy CO2eq emission mitigation is during the storage of manure, which leads to more sustainable fertilizer management practices. Mitigation to reduce methane emissions can also be done by utilizing livestock waste as biogas and improving animal feed additives using chitosan or potassium nitrate.
Research Article
Advanced Energy Technologies
Mina Bahraminasab; Hamed Moqtaderi; Atiyeh Kiaeinejad
Abstract
Microbial Fuel Cells (MFCs) represent an environmentally-friendly approach to generating electricity, but the need to study variation parameters to find improvement conditions has been an important challenge for decades. In this study, a single-chamber MFC was designed to investigate the key parameters ...
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Microbial Fuel Cells (MFCs) represent an environmentally-friendly approach to generating electricity, but the need to study variation parameters to find improvement conditions has been an important challenge for decades. In this study, a single-chamber MFC was designed to investigate the key parameters such as the concentration and type of bacteria, chamber temperature, electrode spacing, and substrate rotation speed that affected the performance of MFCs. Therefore, two types of bacteria, Shewanella oneidensis (S.one) and Escherichia coli (E. coli), were compared as microorganisms. Then, the function of MFC was investigated under the following condition: three temperatures (30 ℃, 45℃, and 60℃), three bacterial concentrations (0.5% (v/v) (4.5 mg/ml), 1% (v/v) (9mg/ml), and 1.5% (v/v) (13.5mg/ml)), electrode distances (2 cm, 3 cm, 4cm), and substrate speeds (100 rpm, 150 rpm, 200 rpm). Ultimately, (S.one) bacteria, a chamber temperature of 45 ℃, a bacterial concentration of 1% (v/v) (9mg/ml), a cathode-anode spacing of 3 cm, and a rotation speed of 150 rpm proved to be the most efficient parameter settings for the constructed microbial fuel cell. The maximum voltage and highest power density were 486.9 mV and 9.73 mW/ , respectively, with a resistance of 7500 ohms. These results are meaningful for determining and improving important parameters in an MFC device.
Research Article
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.
Research Article
Renewable Energy Resources and Technologies
Ararsa Derese Seboka; Fiseha Bekele Teshome; Motuma Tolera Feyissa
Abstract
This study was conducted in the Loka Abaya District of Sidama Region, Southern Ethiopia to assess the environmental impacts of biomass energy production with particular emphasis on charcoal and firewood. The data collection was undertaken using the questionnaire survey administered to 186 randomly selected ...
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This study was conducted in the Loka Abaya District of Sidama Region, Southern Ethiopia to assess the environmental impacts of biomass energy production with particular emphasis on charcoal and firewood. The data collection was undertaken using the questionnaire survey administered to 186 randomly selected households. This task was followed by key informant interviews and an analysis of the literature. The sampled households produced 208 432.9 kg firewood yr-1 for domestic consumption and 261 039.8 kg charcoal yr-1 for sale in town. 2.3x10-6 km2 of the forest is cleared to produce a single sack of charcoal. Charcoal and firewood production is totally responsible for the degradation of 39.4 ha of forest per year. The associated emissions of CO2, CO, N2O, CH4, and TNMHC (total non-methane hydrocarbon) during the production and consumption of firewood and charcoal were calculated based on the emission factors indicated by previous studies. The results demonstrated that the trace gases produced during charcoal making were higher than that of charcoal burning. Further, the amounts of greenhouse gases generated during firewood burning were higher than the ones generated during charcoal burning. In order to minimize the challenges of deforestation and greenhouse gas emissions caused by charcoal and firewood consumption, a strategy of promoting the utilization of alternative clean energy sources such as solar and biogas should be implemented in parallel to the effort of adoption of improved biomass energy-saving cook stoves.
Research Article
Renewable Energy Resources and Technologies
Francis Olatunbosun Aweda; Segun Adebayo; Adetunji Ayokunnu Adeniji; Timothy Kayode Samson; Jacob Adebayo Akinpelu
Abstract
Wind energy has been identified as a critical component in the growth of all countries throughout the world. Nigeria has been identified as having energy issues as a result of poor maintenance of hydro and thermal energy generating stations. As a result, the current study uses some machine learning approaches ...
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Wind energy has been identified as a critical component in the growth of all countries throughout the world. Nigeria has been identified as having energy issues as a result of poor maintenance of hydro and thermal energy generating stations. As a result, the current study uses some machine learning approaches over wind speed data for energy generation in the country. Machine learning models were employed for wind speed using selected meteorological parameters. Little research was done using some meteorological data and machine learning to investigate wind speed across Nigerian sub-stations, resulting in the need for further research. This research, on the other hand, focuses on a neural network for forecasting, a Long Short-Term Memory (LSTM) network model based on several fire-work algorithms (FWA). The data for this study came from the archive of the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) Web service, which was modeled. The LSTM predicts the wind speed model based on the FWA, which used hyper-parameter optimization and was based on a real-time prediction model that was dependent on the change and dependence of the neural network. The study data was split into two categories: test and training. According to the validation technique, the sample data was reviewed, and the first 80% of the data was utilized for training, as revealed by the (LSTM) network model. The remaining 20% of the data was used as forecast data to ensure that the model was accurate. The normalization of the data for the wind speed range of 0 to 1 which illustrates the process data, the high peak in 1985 (a = 0.12m/s, b = 0.11m/s, c = 0.13m/s d = 0.08m/s, e = 0.06m/s, f = 0.10m/s) was discovered. However, the summary result of the performances of different 11 Machine Learning algorithms of regression type for each of the seven locations in Nigeria has different values. As a result, it is recommended that this study will facilitate the prediction of wind speed for energy generation in Nigeria.
Review Article
Renewable Energy Resources and Technologies
Dnyaneshwar S. Malwad; Deepak C. Sonawane
Abstract
Preserving food from harvest to consumer level is a challenge in the agriculture sector. Drying is a crucial post-harvest technique that lowers moisture to levels suitable for storage. Solar drying is a traditional renewable energy drying process. Different solar drying methods have been developed ...
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Preserving food from harvest to consumer level is a challenge in the agriculture sector. Drying is a crucial post-harvest technique that lowers moisture to levels suitable for storage. Solar drying is a traditional renewable energy drying process. Different solar drying methods have been developed to speed up the drying process and maintain the product's nutritious content. Indirect solar drying is one of the efficient drying methods that has better control over the drying temperature. Indirect solar drying has developed into a desirable, effective, and environmentally responsible drying technique when combined with solar collectors and thermal storage. Flat plates, evacuated tubes, and concentrated solar collectors are used in indirect solar dryers along with direct air heating or thermal storage systems. This study aims to review the improvement in the drying rate with different air heating mechanisms. Flat plate collectors with liquid working fluid are employed to heat the air, whereas in evacuated tube collectors, the air is directly heated passing through the tubes. Working fluids, air temperature, air velocity, and solar radiation are important dryer parameters affecting the drying rate. The paper also discusses the usage of heat storage devices for continuous drying operations. The drying time is greatly reduced through integration with latent and sensible storage technologies. Products that have been dried using indirect solar dryer and appropriate drying models are tabulated. Aspects of indirect solar drying and challenges in drying time reduction are also reported.
Research Article
Advanced Energy Technologies
Abraham Olatide Amole; Adebimpe Oluwaseun Adeyeye; Daniel Oluwaseun Akinyele; Kehinde Adeleye Makinde; Stephen Oladipo
Abstract
The use of Diesel Generators (DGs) and gas turbines to power oil rigs is characterized by pollution due to the emission of harmful gases like carbon dioxide, very high noise levels, high maintenance costs, and the inability to start the platform if the DG fails. Offshore wind energy generation system ...
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The use of Diesel Generators (DGs) and gas turbines to power oil rigs is characterized by pollution due to the emission of harmful gases like carbon dioxide, very high noise levels, high maintenance costs, and the inability to start the platform if the DG fails. Offshore wind energy generation system provides a viable alternative means of powering the oil rig and can also be integrated to operate in parallel with gas turbines. However, offshore wind energy might fail if not properly designed due to the high variability of wind resources. Hence, the objective of this work is to design offshore Wind Turbine Generator (WTG) energy generation system, DG, and hybrid DG-WTG for the black start of an offshore oil rig. The designed energy systems are simulated using HOMER Pro. Furthermore, the performance of the simulated systems was evaluated using the electrical production, unmet load, and emission profile as the performance metrics. The results of the hybrid DG-WTG powered black start revealed that 150kW DG generated 322,071kWh/yr representing 6.77% of the total generation and 1.5MW WTG generated 4,434,632kWh/yr representing 93.2% of the total generation. The comparison of the emissions from DG and DG-WTG revealed that 294,058kg/yr, 1,945kg/yr, 80.9kg/yr, 9.02kg/yr, 720kg/yr, and 688kg/yr of CO2, CO, UH, PM, SO2, and NO, respectively, were released into the atmosphere by DG-WTG which is very low compared to 969,129kg/yr, 6,109kg/yr, 267kg/yr, 37kg/yr, 2373kg/yr, and 5739kg/yr of CO2, CO, UH, PM, SO2, and NO, respectively, released into the atmosphere by DG. The sensitivity analysis revealed that while the electrical production of 100kW and 50kW DGs decreased with an increase in WTG height, the electrical production of 1.5MW WTG increased with an increase in WTG height. It was further revealed that the higher the WTG height the smaller the quantity of the emission released into the atmosphere.
Research Article
Environmental Impacts and Sustainability
Ali Sayyadi; Mohamad Javad Amiri
Abstract
One of the environmental problems today is the rising land surface temperature and the formation of heat islands in metropolitan areas, which have arisen due to the unplanned expansion of these cities. Satellite imagery is widely used in urban environmental studies to provide an integrated view and reduce ...
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One of the environmental problems today is the rising land surface temperature and the formation of heat islands in metropolitan areas, which have arisen due to the unplanned expansion of these cities. Satellite imagery is widely used in urban environmental studies to provide an integrated view and reduce costs and time. In this study, Landsat satellite imagery in TM, ETM+, and OLI sensors from 1984 to 2020, remote sensing techniques, and GIS is used to analyze the data, and SPSS software is employed to examine the correlation between the data. The results indicate that the land surface temperature in District 1 of Tehran has increased during the last 38 years. Moreover, land use in District 1 has changed significantly over this period, and urban land use increased from 16% (1984) to 35% (2020) while vegetation declined from 32% to 14%. The results of linear regression analysis show a significant correlation between satellite images and weather station data. The significance coefficient (Sig) in all stations is less than 0.05 with a 95% confidence interval. Besides, the coefficient of variation (R) for all stations is above 80%, and the coefficient R2 has a desirable value. The findings suggest that the trend of rising temperatures in District 1 of Tehran has become an environmental problem and the changes in land use such as declining vegetation and increasing the acceleration of urbanization are among the factors that affect it.
Research Article
Renewable Energy Resources and Technologies
Satyaprasad Mohapatra; Akshaya Kumar Patra; Debswarup Rath
Abstract
The design of a Spotted Hyena Optimization Algorithm-Variable Parameter Tilt Integral Derivative with Filter (SHO-VPTIDF) controller for improved performance and enhanced devaluation of harmonic components of grid-connected photovoltaic systems is the main objective of the suggested manuscript. The SHO-VPTIDF ...
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The design of a Spotted Hyena Optimization Algorithm-Variable Parameter Tilt Integral Derivative with Filter (SHO-VPTIDF) controller for improved performance and enhanced devaluation of harmonic components of grid-connected photovoltaic systems is the main objective of the suggested manuscript. The SHO-VPTIDF controller is proposed by reformulating Tilt Integral Derivative Controller with Filter (TIDCF). The TIDCF is characterized by longer simulation time, lower robustness, longer settling time, attenuated ability for noise rejection, and limited use. This research gap is addressed by replacing the constant gains of TIDCF by variable parameter tilt integral derivative with filter. The VPTIDF replaces the constant gains of TIDCF with error varying control parameters to improve the robustness of the system. The photovoltaic system with nonlinearities causes power quality issues and occasional faults, which can be detected by using Levenberg-Marquardt Algorithm (LMA) based machine learning technique. The novelties of the proposed manuscript including improved stability, better robustness, upgraded accuracy, better harmonic mitigation ability, and improved ability to handle uncertainties are verified in a Matlab simulink environment. In this manuscript, the SHO-VPTIDF and the Direct and Quadrature Control based Sinusoidal Pulse Width Modulation (DQCSPWM) method are employed for fault classification, harmonic diminishing, stability enhancement, better system performance, better accuracy, improved robustness, and better capabilities to handle system uncertainties.
Research Article
Renewable Energy Resources and Technologies
Reza Roohi; Masoud Akbari
Abstract
The design of novel and effective receivers is one of the most challenging aspects of solar energy harvesters, especially for Parabolic Dish Collectors (PDCs). The variation of solar flux due to the solar time and sky clearance index can affect the output thermal energy of the collector. One of the major ...
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The design of novel and effective receivers is one of the most challenging aspects of solar energy harvesters, especially for Parabolic Dish Collectors (PDCs). The variation of solar flux due to the solar time and sky clearance index can affect the output thermal energy of the collector. One of the major approaches to producing a uniform performance for the PDCs is the utilization of Phase Change Materials (PCMs). The PCMs can absorb the solar flux at its peak instances. Subsequently, due to the thermal buffering effect, excess energy is released in cases with lower solar flux. In the present study, a novel design of receiver with multiple layers of thin PCM inserted between the passages of the working fluid is numerically simulated. The simulations are designed to determine the effect of operational parameters on the performance of the examined novel receiver. According to the results, by increasing the Heat Transfer Fluid (HTF) flow rate from 60 to 90 kg/h, the system efficiency is increased from 53.8 to 66.4 %.
Research Article
Advanced Energy Technologies
Mohammad Saleh Barghi Jahromi; Vali Kalantar; Mohammad Sefid; Masoud Iranmanesh; Hadi Samimi Akhijahani
Abstract
Paraffin waxes are widely used as commercial organic heat storage phase change (PCM) for many applications due to their suitable properties; high heats of fusion, nonpoisonous, stable properties, no phase separation, and the phase process only results in a small volume change. Meanwhile, it suffers from ...
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Paraffin waxes are widely used as commercial organic heat storage phase change (PCM) for many applications due to their suitable properties; high heats of fusion, nonpoisonous, stable properties, no phase separation, and the phase process only results in a small volume change. Meanwhile, it suffers from low thermal conductivity. Various techniques can be enhanced the thermal conductivity of PCMs by incorporating the dispersion of high-conductivity particles or nanomaterial in the PCM itself and employing metal foams. Using nanoparticles has the disadvantages of an expensive cost and particle deposition after various cycles. Hence, in this study, some experiments were carried out to investigate the effect of porous media like copper foam and iron wool as the filler instead of nanomaterials on improving the heat conductivity of PCM. The results show that the porous foam increases the heat transfer and during the charging operation, the temperature of the porous plate wall increases continuously at the same rate as the paraffin. In 2400 s, the temperature of pure PCM, iron wool and copper foam reaches 67.3, 72.5 and 73.27℃ , respectively. The optimal mode is the one where the copper absorber plate is connected to the copper foam, reducing the charging time by 600 s compared to pure PCM and saving 75% of energy. Connecting the copper absorber plate to the iron wool has a good thermal performance and stores 70.83% of energy, so the iron wool has an acceptable performance and is suitable for storage systems.
Research Article
Advanced Energy Technologies
Ala Moradi; Hajar Es-haghi; Seyed Hassan Hashemabadi; Magid Haghgoo; Zahra Emami
Abstract
Due to their high energy storage capacity, phase change materials (PCMs) have received significant attention as thermal energy storage systems. However, their low thermal conductivity reduces the rate of heat transfer. Incorporating nanoparticles into the matrix of PCM can be an efficient way to solve ...
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Due to their high energy storage capacity, phase change materials (PCMs) have received significant attention as thermal energy storage systems. However, their low thermal conductivity reduces the rate of heat transfer. Incorporating nanoparticles into the matrix of PCM can be an efficient way to solve their deficiency. In the current research, nano-enhanced phase change materials (NEPCM) based on Eicosane and incorporated nano graphite were prepared, and their thermal characteristics were evaluated. The SEM micrographs of graphite nano-powders, pure Eicosane, and prepared nanocomposites were analyzed. Differential scanning calorimetry (DSC) and thermal conductivity evaluation (TC) of samples were conducted to determine their heat capacity, thermal diffusivity, and thermal conductivity. The results illustrated that the more graphite nanoparticles, the more collision number between graphite and Eicosane. Therefore, nanocomposites' thermal conductivity and diffusivity are increased with nanophase. Furthermore, increasing crystal growth and reducing heat capacity for the high amount of nanoparticles in the composite were discussed.
Research Article
Renewable Energy Resources and Technologies
Samir Tabet; Razika Ihaddadene; Belhi Guerira; Nabila Ihaddadene
Abstract
Dust accumulation on PV surface panels is a crucial factor affecting their performance. It is more frequently noted in the desert zones. The effect of dust on the electrical behavior of damaged PV panels was investigated in this study. Three panels are used: the degraded panels (with and without dust) ...
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Dust accumulation on PV surface panels is a crucial factor affecting their performance. It is more frequently noted in the desert zones. The effect of dust on the electrical behavior of damaged PV panels was investigated in this study. Three panels are used: the degraded panels (with and without dust) and the reference panels; they are located in an industrial zone with a continental climate (Bordj Bou Arréridj, Algeria). The I-V and P-V characterization and degradation mechanism visualization are used. Also, a numerical simulation was conducted to calculate the five parameters of the three modeled PV panels (diode ideality factor (a), series resistance (Rs), Shunt resistance (Rp), photocurrent (Ipv), and diode saturation current (I0)). These parameters were utilized for the first time to study the impact of dust on their degradation rate and the PV panel behavior. The degradation rate and the annual degradation rate of each parameter are affected by dust differently. The power degradation rate is increased by 5.45%. The Isc and Imax degradation rates are climbed by 6.97% and 6.0%, respectively. Vmax and Voc degradation rates decrease by 1.20% and 0.35%, respectively. Dust increased the rate of degradation for a, Iph, and I0 by 4.12%, 6.99%, and 68.17%, respectively. For Rs and Rp, the degradation rate was reduced by 4.51% and 20.01%, respectively. An appropriate netoiling approach must be considered because dust, even in non-desert areas and industrial zones, has a significant impact on the electrical characteristics degradation of a PV panel.
Research Article
Advanced Energy Technologies
Mohammed Ali Sami Mahmood; Rodionov Yuriy Viktorovich; Shchegolkov Alexandr Viktorovich
Abstract
Researchers worldwide are studying thermal energy storage with phase change materials because of their substantial benefits in the enhancement of energy efficiency of thermal drying systems. A two-stage convective-vacuum impulsive drying plant is a technology for the manufacturing of chemical and food ...
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Researchers worldwide are studying thermal energy storage with phase change materials because of their substantial benefits in the enhancement of energy efficiency of thermal drying systems. A two-stage convective-vacuum impulsive drying plant is a technology for the manufacturing of chemical and food products with high quality and low energy costs. Energy consumption during the drying process is the main indicator in terms of economy. In this paper, a brief and focused review of the peculiarities of TEAs with PPCMs and opportunities of their application in such drying systems is done and discussed. The paper described the mentioned manufacturing system. The advantages of paraffin wax and thermal conductivity improvement techniques were demonstrated for their use as heat storage materials in CVID drying units. The results of similar previous studies were presented. The results of the experimental studies conducted by the researchers proved that the use of heat accumulators with PCMs increased the overall energy efficiency of drying systems. Finally, integration of TEAs based on modified PPCMs in the CVID system was recommended to intensify thermal energy, reduce thermal influence on the main indicators of the vacuum pump during the evacuation process, and decrease production costs.
