• Energy Research

AbstractThe integration of solar energy systems into buildings via photovoltaic (PV) and other technologies can curb the amount of greenhouse gas emissions produced by buildings. However, the performance of solar energy systems is highly dependent on climatic and economic conditions. In this regard, the techno‐economic feasibility of building attached PV systems are studied for three scenarios considering three cities of Iran namely Tehran, Tabriz, and Kish Island, which have different climatic conditions. The result shows that the PV systems can annually meet 4.5–20% of the electricity needs for Tehran, 3.0–13% for Tabriz and 2.0–11.5% for Kish Island. Moreover, roof mounted PV systems were found to be a better alternative to envelope attached systems in technical and economic terms. The payback period for the solar energy systems was found to be between 8.7 and 14.3 years for Tehran, 14.2 and 22.6 years for Tabriz, and 11.6 and 21.1 for Kish Island.

As the world population grows rapidly, and the limited amount of fossil fuels begins to diminish along with their impact on the environment, countries have been taking action to promote a greater use of renewable energy resources. In this article, the feasibility of providing electricity from a hybrid power system (HPS) comprising diesel/wind/photovoltaic (PV), and battery considering residential, public, and commercial buildings, consuming the largest portion of energy in Iran is investigated. Tehran, Kish Island, and Binalood are the chosen cities in Iran with distinctive geographic and climatic conditions. In order to determine the optimal design and operational planning of the HPS, the hourly electricity demand data is required to be over 8760 hs during a 1‐yr study. The required hourly data was calculated by employing Carrier (HAP4.5) software. The economic analysis is performed based on net present cost (NPC), cost of energy (COE), diesel consumption, and renewable fraction for all cases by applying HOMER software. Furthermore, sensitivity analyses are carried out to specify the impact of fuel cost on the system by considering two different diesel fuel systems. The results of the economic analysis indicate that Kish Island with warm and temperate climatic conditions would be the optimum zone to install HPS for supplying the energy demand of projected buildings. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 614–623, 2019

Continued reductions in air pollution and greenhouse gas (GHG) emissions are crucial in megacities like Tehran, Iran, as they pose serious threats to both people's health and the environment. Reducing energy use through renewable energy projects will result in the mitigation of GHG emissions. Hence, this study was designed to assess the use of renewable energy resources to provide the energy services for a residential building. The specific objective of this article is to select a hybrid renewable energy system that can meet the energy demand of a 5‐story residential building in Tehran. The energy consumption of the building is calculated using DesignBuilder software. Then, HOMER software is applied to propose an economically feasible solar‐wind hybrid system that can meet the energy demand of the building. Initially, information required for HOMER and DesignBuilder software such as the building plan, details on electrical appliances used in the building, solar radiation, wind speed, and cost of renewable systems were collected. Subsequently, the energy performance of the building was simulated in DesignBuilder software and the results were applied to HOMER software. Finally, the hybrid systems proposed by HOMER were economically compared. Furthermore, the emissions produced by the proposed system were evaluated against a diesel only system to assess the amount of offset emissions. The comparison of the hybrid and diesel systems shows that utilization of hybrid systems can significantly reduce the magnitude of GHG emissions along with achieving cost saving. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

The optimal arrangement of wind turbines plays a significant role in obtaining the expected output power from wind farms. This paper addresses challenges related to typical restriction assumptions of turbine arrangement in wind farms with candidate selection approach. An applicable hybrid (quadratic assignment problem-genetic algorithm) evolutionary method with an initial candidate points selection (ICPS) approach is proposed and applied to four case studies to obtain optimal layout designs with maximum efficiency. The current study considers not only the previously utilized indicators found in the literature, such as wake effects, turbine hub height and rotor diameter, but also accounts for additional criteria such as the load-bearing capacity of soil and restrictions regarding the existence of prohibited places as well as varying wind velocities and directions. This is done to make the approach more applicable for realistic cases, and also to incorporate the preferences of expert designers. The results suggest that superior performance is attained with the proposed algorithm compared to previous similar studies. An efficiency improvement of about 3% is achieved for case one, and the algorithm provides reasonable optimal wind farm design layouts for cases two, three, and four where more restrictions exist.

Abstract Widespread application of plug-in hybrid electric vehicles (PHEVs) as an important part of smart grids requires drivers and power grid constraints to be satisfied simultaneously. We address these two challenges with the presence of renewable energy and charging rate optimization in the current paper. First optimal sizing and siting for installation of a distributed generation (DG) system is performed through the grid considering power loss minimization and voltage enhancement. Due to its benefits, the obtained optimum site is considered as the optimum location for constructing a movie theater complex equipped with a PHEV parking lot. To satisfy the obtained size of DG, an on-grid hybrid renewable energy system (HRES) is chosen. In the next set of optimizations, optimal sizing of the HRES is performed to minimize the energy cost and to find the best number of decision variables, which are the number of the system’s components. Eventually, considering demand uncertainties due to the unpredictability of the arrival and departure times of the vehicles, time-dependent charging rate optimizations of the PHEVs are performed in 1 h intervals for the 24-h of a day. All optimization problems are performed using genetic algorithms (GAs). The outcome of the proposed optimization sets can be considered as design steps of an efficient grid-friendly parking lot of PHEVs. The results indicate a reduction in real power losses and improvement in the voltage profile through the distribution line. They also show the competence of the utilized energy delivery method in making intelligent time-dependent decisions in off-peak and on-peak times for smart parking lots.

Abstract Utilization of wind turbines to produce energy has been increasing in recent years, due to technology advancement, cost stability and environmental issues. In this paper, the wind resource and economic feasibility have been studied to avoid investment risk in cites of Zabol, Zahak, Zahedan and Mirjaveh in Sistan and Balouchestan province of Iran. The Weibull distribution function has been applied to estimate the wind power and energy density, using meteorological data. Determination of coefficient, root mean square error, mean bias error and mean bias absolute error are also calculated to ensure the accuracy of the statistical analysis of fitted distribution. Windographer software has been employed to investigate the prevailing wind direction. The estimated annual energy densities are 2495.36, 2355.69, 1265.24 and 1214.01 kWh/m2/year, and the annual mean power densities are 284.97, 269.02, 144.49 and 138.64 W/m2. It is found that Zabol and Zahedan are suitable for large scale power generation. The results indicate that using DW61-900 kW wind turbines are highly beneficial for Zabol and Zahak, while for Zahedan, DW52/54-250 kW wind turbine is more appropriate for generating electricity. However, Mirjaveh is suitable for off-grid applications. It should be noted that in this analysis, monetary units are presented in 2016 U.S. dollar.

Abstract Renewable energy is receiving increasing interest from industry and government in Iran. Among the many types of renewable energy available in the country, wind energy is currently one of the fastest growing, most commonly used and commercially attractive renewable sources for generating electricity. In this paper, the wind energy potential is assessed for four locations in Bushehr province of Iran: Asaluyeh, Bordkhun, Delvar and Haft-Chah. The analysis utilizes wind speed data measured in 2011 at heights of 10 m, 30 m and 40 m above ground level. The goal is to improve understanding of the potential of wind energy for the selected locations and to thereby improve the prospects for its usage. The Weibull probability distribution function is employed to calculate the wind power density and energy for the regions. We found that the Weibull distribution fits the experimental data well over an acceptable range. The statistical analyses of the wind data include estimations of the monthly and diurnal mean wind speed cumulative curves, and the creation of wind rose diagrams. The results indicate that Bordkhun has better potential for using wind energy than the other three areas in the province examined. The annual mean wind power density for this location is found to be about 265 W/m2 for winds at a height of 40 m. Energy analyses are used to determine the best wind turbines for each location. Twelve wind turbines with generating capacities ranging from 1 kW to 100 kW are examined, and the annual capacity factor and annual energy output of the selected wind turbines are calculated. A comparison of the results for the wind turbines indicates that the Proven 15 has the highest capacity factor and economically is the best choice for all of the locations considered.

Abstract In an attempt to discover alternative energy sources to fossil fuels which are being depleted on the increase, Renewable Energy Sources (RES) have gained considerable attention in recent years. RESs are also represented as clean sources; emitting comparatively lower Greenhouse Gases (GHGs) emissions; thus, they are climate friendly. Among RESs, wind energy is one of the most abundant and increasingly cost-competitive energy resources, and it is becoming the fastest growing source of electricity in the world. Regarding the improvement of wind power, one of the key aspects that must be considered is achieving enhanced reliability and efficiency at once. In this paper, we introduced and applied an innovative method to make wind dam which is a new approach to wind farms’ site selection for production of electricity. The proposed method enhances the wind potential by means of a natural or artificial barrier such as a hill, and is supported by analytical expressions and Computational Fluid Dynamics (CFD) models. A systematic case study has been designed at a site near the city of Tehran, Iran, and an analytical method has been applied that includes meteorological data analysis, CFD modeling along with energy power and economic assessment.

The development and modeling is reported of a photovoltaic (PV)/wind/diesel hybrid power generation system for a household in Winnipeg, Manitoba, Canada. For optimizing and determining the feasibility of the system, Homer simulation software is utilized. Various system configurations are investigated and comparisons are made using an optimization approach. For the Winnipeg location, the annual mean and the peak loads are 16 kWh/d and 1.9 kW, respectively. It is found that the hybrid system comprising 1 kW PV arrays, a 2 kW diesel generator, five batteries and a 2 kW converter with a total net present cost of $33,110 and a cost of energy of 0.444 $/kWh has the optimal configuration. The results obtained with Homer software demonstrate that a hybrid wind/PV/diesel/battery power generation system has the lowest cost and the highest efficiency of the systems considered. The system helps reduce emissions of pollutants and greenhouse gases. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 548–562, 2019

Recent research studies have shown the advantages of using double-skin façade (DSF) and phase change material (PCM) in reducing the amount of building heat, especially for tropical and subtropical climates. Also, by adding photovoltaic (PV) cells in the facade of buildings, the solar heat of the building can be reduced and the electricity generated can lower the energy cost of the building. Since there is a strong interdependence among the energy performance of DSF, PV, and PCM as well as weather conditions, geography, and building orientation, in this paper, their simultaneous energy performance is studied under different climatic conditions of Iran. Also, all the cases are compared from an economic point of view. Based on the results obtained in this research, it can be concluded that the implementation of DSF and integration of PCM with it in the Mediterranean climate, the cold semi-arid climate, and the warm semi-arid climate of Iran is technically possible and offers the benefits of energy saving by changing the quality of spaces by using daylight as well as controlling the solar system, natural ventilation, sound insulation, and thermal insulation in winter and summer.