Original Article
Solar Thermal Engineering
Mahdi Rezaei Rad; Rouzbeh Shafaghat; Amirhossein Aghajani afghan; Behrad Alizadeh Kharkeshi
Abstract
This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north ...
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This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north of Iran (Mazandaran province, Babol), and the effect of the inlet air's temperature and flow rate on the system's functional characteristics and condenser was investigated to improve the performance. Sensors measured the data related to the fluid temperature and humidity of the cycle at different points; other data was also gathered by psychrometric chart and EES software. The results section investigates water generation rate, GOR, coefficient of performance (COP), and condenser efficiency. The results showed that the highest water production is 420 g/hr, and the highest GOR is 0.19. Also, the water production rate and COP increase as the inlet air temperature rises. At temperatures lower than 75o Celsius, due to the air saturation, the maximum point of the water production and COP occurs at a flow rate of 0.022 kg/s. at high temperatures, increasing the flow rate raises water production, and on the other hand, the COP in the condenser is 0.8 at the highest point. According to the economic analysis done for the proposed model, the freshwater cost is 0.098-0.049 $/year for one liter.
Original Article
Mojtaba Ghiyasi
Abstract
Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse ...
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Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse DEA approach as a valuable method for the future planning of the IWPPs. In this step, we considered five different scenarios from a short-run up to a long-run planning for electricity production by renewable energy. In the short-run we just need more capacity factor rather than capital. Although in the mid-run we did not presume capital extension, the result suggested this. In the end, in the long-run planning extension in not only capacity factor but also more investment in the higher technologies is a requirement for reaching the desired electricity production.
Original Article
Tide, Wave and Hydro Power
Hosein Jokar; Abuzar Abazari; Reza Dorostkar
Abstract
One of the main needs for dhow vessels is fuel for diesel generators that generate electricity, which in turn is used in refrigerators and electronic devices. Concerning the development of new devices for electricity generation such as point absorber wave energy converters, in the present research for ...
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One of the main needs for dhow vessels is fuel for diesel generators that generate electricity, which in turn is used in refrigerators and electronic devices. Concerning the development of new devices for electricity generation such as point absorber wave energy converters, in the present research for the first time, the feasibility of installing such converters on the hull of the dhow vessel and their performance is being examined. These WECs expanded on the sea-free surface level during anchoring time. Depending on the relative angular displacement between the WEC and the dhow hull the electricity is produced. In the present study, the simulations are done based on the diffraction theory in Ansys AQWA. The results showed that for considering four installed WECs, the maximum output power of 400 kilowatts is produced, which is an acceptable amount of energy for supplying the common electronic devices on the dhow vessel. In addition to this, it has been shown that the hybrid system of the dhow and WECs in the anchoring mode has fewer dynamic responses compared to a single dhow without WECs. Such conditions can be utilized for the comfort of the passengers or special operations during the anchoring time. It was also observed that the buoy size does not have a considerable effect on the production power and dynamic response of the platform, while the length of 2 m for the lever and angle of 90 degrees of the incident wave is optimum from the production power point of view.
Original Article
Solar Thermal Engineering
Fatemeh - Ahani; Elham - Sarkardehi; Maryam - Ansarimanesh; Hamed - Moslehi
Abstract
Approximately 40% of fossil energy consumption in Iran is attributed to office and residential buildings. Therefore, optimizing energy consumption and managing energy demand in these buildings is essential. A key aspect of this optimization is the building's outer shell, which plays a vital role ...
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Approximately 40% of fossil energy consumption in Iran is attributed to office and residential buildings. Therefore, optimizing energy consumption and managing energy demand in these buildings is essential. A key aspect of this optimization is the building's outer shell, which plays a vital role in heat control. One effective method for reducing energy consumption in buildings is the implementation of double-skin facades (DSFs), which have demonstrated superior performance compared to single-skin facades. Considering the high energy consumption of office buildings in Iran, this research aimed to minimize energy use in the computer center building at Shahrood University of Technology. The research methodology consisted of a literature review, field measurements, and simulation. The validity of the research data was evaluated against field measurements, and its accuracy was confirmed. Using Design Builder version 7 simulation software, twelve models of double-skin facades were analyzed and categorized into box window facades and shaft boxes, both located on the southern elevation of the computer center building. The results indicate that the double-skin facade featuring a box window reduces the building's energy consumption by 6.4% to 9.7% compared to the single-skin facade. Additionally, the double-skin facade of the shaft box also decreases energy consumption, ranging from 5.5% to 9.3% compared to the single-skin facade.
Original Article
Energy Policy
Hossein Heirani; Seyed Mohammad Shobeiry
Abstract
This paper analyzes the life cycle of Iran's wind energy innovation system through a co-evolutionary framework that examines the interplay between the system and its contextual environment. Our analysis reveals that the system is transitioning from formation to growth, but remains vulnerable due ...
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This paper analyzes the life cycle of Iran's wind energy innovation system through a co-evolutionary framework that examines the interplay between the system and its contextual environment. Our analysis reveals that the system is transitioning from formation to growth, but remains vulnerable due to its high dependence on contextual factors. By examining three historical phases, we demonstrate how political, geographical, and sectoral contexts have critically influenced the system's development trajectory. The research identifies key systemic problems across functional, structural, and contextual dimensions, showing how their dynamics have either facilitated or hindered growth. Based on these findings, we propose policy recommendations focused on infrastructure stabilization, institutional support, and contextual management to overcome barriers and enhance the system's resilience and performance. This co-evolutionary perspective offers policymakers a novel framework for understanding and addressing the complex challenges facing renewable energy innovation systems.
Original Article
Electricity Generation by Green Energy Sources
Kaveh Soleimani; Ataollah Gharechae; Mohammad Javad Ketabdari
Abstract
This research evaluates the feasibility of utilizing wave energy at Chabahar Port as an alternative power source. The first part of the study analyzed seasonal and annual wind and wave characteristics, as well as the directional distributions of winds and waves, utilizing long-term buoy measurements. ...
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This research evaluates the feasibility of utilizing wave energy at Chabahar Port as an alternative power source. The first part of the study analyzed seasonal and annual wind and wave characteristics, as well as the directional distributions of winds and waves, utilizing long-term buoy measurements. The extractable power output was determined based on the wave scatter diagram for Chabahar Port and the power matrix of various existing wave power devices. The average annual wave power at this location is 4.1 kW/m. However, wave power exhibited significant variation across the autumn, winter, spring, and summer seasons, averaging 1.46, 1.48, 4.4, and 6.94 kW/m, respectively. Among the thirteen wave power concepts evaluated, the Wave Dragon and the 1500 kW Pelamis demonstrated the best performance. The Wave Dragon is identified as the preferred wave power device for Chabahar Port, considering its power production capability, seabed compatibility, and adaptability to diverse meteorological conditions. Additionally, RETScreen Expert software was employed to conduct a cost and emissions analysis, indicating that the Wave Dragon and Pelamis can reduce greenhouse gas emissions by 719.7 and 351.6 tons of carbon dioxide, respectively. Consequently, the Wave Dragon offers the most economical power solution for Chabahar Port, with a greater reduction in greenhouse gas emissions.
Original Article
Energy Policy
Seyed Zaman Hosseini; Farhad Hossinzadeh Lotfi; Mahnaz Ahadzadeh Namin
Abstract
Assessment of progress and regression of organizations is necessary to determine their performance and determination of the efficacy of managerial decisions, supply usage, and weak and strong points for the senior managers and decision-makers. They can improve the efficiency of the units based on this ...
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Assessment of progress and regression of organizations is necessary to determine their performance and determination of the efficacy of managerial decisions, supply usage, and weak and strong points for the senior managers and decision-makers. They can improve the efficiency of the units based on this assessment. In this paper, using data envelopment analysis, the performance of regional electric companies of Iran in 2015 and 2016 is assessed. Because of semi-positive and negative indexes, the Slack-Based Measure (SBM) model of efficiency is developed for the 16 regional electric companies of Iran. To determine progress and regression in 2016 compared with 2015, models are proposed to compute the indexes of productivity. Finally, solving the proposed models, the Malmquist productivity index is computed for regional electric companies of Iran with 18 input, intermediate and output indexes and considering the amount of production of renewable energies as one of the important output indexes because of the irrefutable necessity of this kind of energies in the world. Their progress and regression are obtained using the Gams software showing progress in two companies, and regression in 13 companies while one company had neither progress nor regression. Studies performed show that agility of the organizational structure, financial and human resource limitations, sanctions and imbalance between the actual price of production of one kilowatt-hour of electricity and its sale price are most effective factors on the progress and regression of the companies.
Review Paper
Energy Policy
Abolfazl Dehghanmongabadi; Zahra Tahmasbnia
Abstract
In recent decades, rapid urbanization and increasing demands for energy created serious challenges in energy supply and environmental conservation. Based on this fact that 71% to 86 % greenhouse gas emissions are from energy consumption in urban areas, the importance of using renewable energy sources ...
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In recent decades, rapid urbanization and increasing demands for energy created serious challenges in energy supply and environmental conservation. Based on this fact that 71% to 86 % greenhouse gas emissions are from energy consumption in urban areas, the importance of using renewable energy sources becomes increasingly evident. In this regard, the main objective of this research is to identify social sustainability indicators and strategies for developing the use of renewable energy in cities based on identified indicators. This research attempts to respond to the raised questions by conducting a narrative review of existing studies based on the scoping review methodology. The findings of this study examine the challenges in using renewable energy resources and emphasize that to increase the use of renewable energy sources, special attention must be paid to various indicators that affect social sustainability in urban communities. The findings of this study demonstrate that social sustainability indicators play a key role in increasing the use of renewable energy in urban communities, and that attention to these indicators can contribute to the sustainable development of energy in cities. Consequently, recommendations to promote the use of renewable energy in urban communities with an emphasis on social sustainability indicators have been presented.
Original Article
Wind Energy
Ali Khaleghi; hadi bayat
Abstract
The noise generated by a blade is assumed as one of the most central acoustic generation sources in a turbine. The sound induced by the movement of turbulent fluid over the turbine blade and its interaction with the surrounding environment causes the presence of vortices of different sizes in the turbulent ...
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The noise generated by a blade is assumed as one of the most central acoustic generation sources in a turbine. The sound induced by the movement of turbulent fluid over the turbine blade and its interaction with the surrounding environment causes the presence of vortices of different sizes in the turbulent flow. These vortices are considered as the major sources of acoustic waves in a wide range of frequencies. In the present study, the acoustic field induced by turbine blades is simulated by the aid of numerical simulation. In this respect, the flow_field around the blades is solved by using the flow governing equations and then the acoustic solution of flow is modeled by using the Ffowcs Williams-Hawkings acoustic model. The main objectives of the present study include investigations of sound propagation at different distances of turbine axis, the extent of sound propagation along the blade direction, and the effect of the cavity implemented over the blade on acoustic results. The obtained results reveal that the sound pressure level generally decreases as the observer’s distance increases. Furthermore, based on the obtained results, one can infer that the reduction in the sound pressure level is triggered by the presence of larger vortices with higher energy close to the blade (a larger sound pressure level) and smaller vortices at a further distance from the blade (a lower sound pressure level). Numerical simulations indicate that adding a cavity to the turbine blade does not reduce noise but instead increases the acoustic generation level.
Original Article
Wind Energy
Samad Emamgholizadeh; E.Yu. Rakhimov; N.R. Avezova; F.Z. Jamoldinov; M. Ziaii
Abstract
This study analyzes wind speeds across various regions of the Republic of Uzbekistan to assess wind potential at 10 meters above ground level. Utilizing meteorological data from 77 ground-based stations collected between 2000 and 2022 at three-hour intervals, wind power densities were calculated to evaluate ...
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This study analyzes wind speeds across various regions of the Republic of Uzbekistan to assess wind potential at 10 meters above ground level. Utilizing meteorological data from 77 ground-based stations collected between 2000 and 2022 at three-hour intervals, wind power densities were calculated to evaluate wind potential, with average wind speeds determined monthly and annually. Data analysis from 13 regions identified locations with high wind energy potential, computing wind power densities and Weibull distribution parameters for wind speeds. Maps of average annual wind speed and power distribution, along with wind rose diagrams, illustrated predominant wind directions essential for optimal wind turbine placement. The highest average wind speeds were recorded in the Republic of Karakalpakstan, Navoi, Bukhara, Dehkanabad district (Kashkadarya), and Bekabad city (Tashkent region). Notable wind potential was found in Jaslyk district (Karakalpakstan) at 202.01 W/m², Navoi city (94.05 W/m²), and Dehkanabad district (85.33 W/m²). These results suggest that regions with high wind potential offer significant opportunities for efficient wind energy use. A comparison with previous studies on Uzbekistan's wind potential confirmed the accuracy and reliability of the data, indicating a high degree of consistency. This information can guide optimal planning and strategic placement of wind energy installations, furthering the development of “green energy” and enhancing Uzbekistan’s energy security
Original Article
Energy Policy
Balu P; Saravanakumar V; Saravanan C; Navaneetha Krishnan P
Abstract
Renewable and cleaner diesel engine fuel has received a lot of attention recently as a result of the depletion of fossil resources. In light of this, biodiesel has proven to be a viable substitute for diesel fuel. The finest B20 Jamun blends were combined with three different types of nano-additives ...
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Renewable and cleaner diesel engine fuel has received a lot of attention recently as a result of the depletion of fossil resources. In light of this, biodiesel has proven to be a viable substitute for diesel fuel. The finest B20 Jamun blends were combined with three different types of nano-additives to create Syzygium cumini (Jamun) biodiesel, which was tested in a naturally aspirated diesel engine. Global researchers are increasingly developing novel nano-additives, recognizing them as a promising and effective approach for enhancing fuel properties and engine performance. This technology was combined with different biodiesels. Also included in this chapter is an examination of a test engine using three distinct nano-additives: titanium dioxide (TiO2), zirconium oxide (ZrO2), and cerium oxide (CeO2). These additives were combined to create the best blends of Syzygium cumini (B20), and the results were evaluated based on factors such as performance, combustion, and output emissions. Additionally, a proposal is made to further improve the construction of a realistic and economically feasible nanoparticle addition for diesel and biodiesel fuel.
Original Article
Photovoltaic Systems
Maede Khakpour; Yaser Karimi; Mohammad-Hadi Zare
Abstract
To address key challenges in the widespread adoption of electric vehicles, this article introduces a bidirectional, integrated on-board battery charger capable of flexibly drawing power from various AC sources, such as single-phase and three-phase grids, as well as renewable energy DC sources like photovoltaic ...
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To address key challenges in the widespread adoption of electric vehicles, this article introduces a bidirectional, integrated on-board battery charger capable of flexibly drawing power from various AC sources, such as single-phase and three-phase grids, as well as renewable energy DC sources like photovoltaic (PV) energy systems. The charger is designed for vehicles with an open-end winding motor powered by a dual inverter, consisting of two three-phase traction inverters and two sets of batteries. The proposed design utilizes a bidirectional current source converter at the input stage and integrates the dual inverter and the motor windings' leakage inductance as part of the charger, reducing both size and cost. Operating bidirectionally, the charger supports various grid support strategies, offering controlled active and reactive power with low total harmonic distortion (THD) in the grid current. It can also be directly connected to PV panels or DC fast-charging stations. A zero-net-torque-generating, interleaved switching pattern is employed to control the dual inverter switches, minimizing current ripple throughout the system. This article provides a detailed explanation and analysis of the proposed integrated charger, with system feasibility and performance validated through simulations.