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Today, using systems based on renewable resources is a suitable alternative to fossil fuels. However, due to problems such as the lack of access in all the times needed to supply cargo and high‐investment cost, it has not been well‐received. In this research, in addition to maintaining the technical specifications and increasing the reliability of the system due to the addition of the hydroelectric power plant to other wind and solar systems, it has been tried to use biodiesel fuel (biofuel) as an alternative to fossil fuel in the diesel generator. To identify the most economical combination of the system with the application of social costs and the limit of pollutant and greenhouse gas emission in independent mode with the help of Homer software. the results showed that adding biodiesel to the designed system, the investment costs will increase by $282,038, which has a direct impact on the cost of energy and causes an increase of 0.0115 $/kWh. While the use of biodiesel reduces the emission of carbon dioxide by 28,947 kg/year. [ABSTRACT FROM AUTHOR]

This study aimed to provide a techno‐economic analysis of hybrid energy systems, including wind turbines, photovoltaic systems (PV) panels, diesel generators, and batteries, for selected cities in five different climate zones in Spain to meet the load requirements of industrial towns. Homer software was used to determine the most efficient configuration for supplying the average load of the industrial sector, with a value of 1500 kWh/day and a peak load of 114.58 kW, and the residential sector, with a value of 150 kWh/day and a peak load of 27.85 kW. Optimization is carried out to minimize the evaluation parameters of net present cost (NPC) and cost of energy (COE). According to the software outputs, it appears that the system utilizes a variety of renewable energies. The priority is to use all hybrid system components, and the wind–PV–diesel–battery configuration has performed best in all cities. The cities of A Coruña, Bilbao, Ponferrada, Almería, Barcelona, Salamanca, Seville, Zaragoza, and Madrid, respectively, with NPC values of 1.39, 1.67, 1.76, 1.92, 2.23, 2.29, 2.39, 2.55, 2.61 M$ and COE values of 0.199, 0.24, 0.252, 0.276, 0.32, 0.329, 0.343, 0.366, 0.374 $/kWh have economic efficiency from the highest to the lowest. Reducing pollution production is one of the key reasons for approaching hybrid technologies. In this regard, A Coruña has the lowest carbon emissions among the selected cities, with 25,190, and 95.5% of its energy production is renewable. On the other hand, Madrid, which uses 89% renewable energy, has the highest carbon dioxide production with a value of 59,242. The system analysis in different cities of Spain provides insight into the conditions necessary for establishing such systems in different climate zones, which can serve as a road map for other places in the country. [ABSTRACT FROM AUTHOR]

The randomness of generated power by renewable energy resources has led experts in this field to provide sustained and permanent load supply with hybrid renewable energy systems (HRESs). This study investigates the modeling of an off‐grid HRES based on the wind turbine/photovoltaic/gas generator for supplying the consumption of a residential complex in Tehran (capital of Iran). To this end, the HOMER software has been implemented. After calculations, the capital cost and cost of energy of each component are estimated in different HRES models. In addition, parameters such as power generation, emissions, and thermo‐economic analysis of different models of the hybrid system have been investigated. Two models of optimum HRES (based on the lowest net present cost [NPC]), with and without wind turbines, were compared. According to the results, the fuel consumption and emissions caused by the operation of the gas generator will decrease by 53% as a result of using a wind turbine despite an 8% increase in NPC. This is an important achievement regarding high air pollution in Tehran. Based on the results, using a gas generator instead of a diesel generator leads to an 18% decrease in NPC. Additionally, in comparison to using a gas generator only, using the hybrid system leads to a 43% reduction in NPC. [ABSTRACT FROM AUTHOR]

Solar and wind can be considered as sustainable environmentally friendly and omnipresent renewable energy sources for generating a part of required electrical energy for inhabitants of the remote areas in different countries. Accordingly, this study investigates the techno‐economic evaluation for two‐hybrid renewable energy systems for Bandar Dayyer. The findings of this study shows that using the HOMER software, the total amount of electricity production by these systems are equal to 470,176 kW, of which 22,409 kW is provided by PV‐generic system and 447,767 kW is supplied by PV‐diesel‐generic system. It should be mentioned that this area has an appropriate potential of wind speed and solar radiation; therefore, the area can be suitable for investing on a hybrid renewable energy site. [ABSTRACT FROM AUTHOR]

Digital databases of monthly means of daily extreme, minimum (Tn) and maximum (Tx) air temperature collected in Ukraine were created. The databases contain temperature records of 371/340 (Tn/Tx) climatological stations which recorded data on the territory of Ukraine anytime during 1881–2015. The significant part of the data sets (~48/47%) was obtained after conducting a data rescue process, recovering historical paper records. Due to a great deal of missing data during World War I and II, homogenization was possible to perform only for 178 time series covering the period of 1946–2015. A homogenization procedure, conducted by means of the HOMER software, revealed 323 break points for minimum temperature (~1.8 breaks per station) and 310 for maximum temperature (~1.7 breaks per station). Approximately 37/33% (Tn/Tx) of the breaks can be explained by metadata. Shift amplitudes in Tn time series ranged between −1.18 and 1.71 °C, while for maximum temperature the range was slightly less from −0.99 to 1.15 °C. For both temperatures, mean values of shift amplitudes were near zero (−0.04/−0.05 °C). To validate the homogenization results, several statistical procedures were performed to compare inhomogeneous and homogeneous time series. The conducted statistical calculations provide the proofs that inhomogeneity of the Ukrainian extreme air temperature data should be taken into account when analysing regional climate change and variability. Detection of recent climate changes is a problem that is mainly solved based on analysis of long time series of observed/measured meteorological variables such as air temperature and precipitation. However, such the time series are usually affected by outliers and artificial abrupt shifts and/or gradual trends, which are not related to climate but reflect changes in observing practices and/or the surrounding environment. Furthermore, an amplitude of the shifts is frequently the same order of magnitude as an amplitude of a climate signal. Therefore, in order to conduct climatological studies of high quality and draw reliable conclusions it is necessary to use quality controlled and homogeneous data. In this paper, homogeneity of long monthly mean of daily extreme (minimum and maximum) air temperature time series collected in Ukraine has been investigated by means of the HOMER software. Revealed shifts and their influence on the time series have been studied in details. [ABSTRACT FROM AUTHOR]

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 [ABSTRACT FROM AUTHOR]

ABSTRACT A database of monthly mean air temperature data collected in Ukraine has been created. The database contains records of 514 stations, which were working at one time or another during the period 1812-2014. Metadata have also been collected using the available descriptions of the stations' histories. Regular observations at a sufficiently large number of stations contained in the database began in the early 1880s. However, due to the disruptions that occurred during World Wars I and II and resulted in a lot of missing data, a reliable homogenized data set can be obtained only for the period 1946-2014. For this period, we have homogenized the data from 178 stations by means of the HOMER software. The total number of breaks that we have identified is 287. However, only approximately 31% of them can be explained by the station relocations or other reasons. The shift magnitudes in annual series do not exceed ±1 °C with the small negative mean value. Therefore, on average, the inhomogeneities of the time series have an effect of increasing the past temperature slightly over the territory of Ukraine and, consequently, decrease the rate of the temperature rise. The trend analysis of the raw and homogenized time series confirms this conclusion. The homogenized data show a more realistic pattern of the spatial distribution of the temperature tendencies, in contrast to many artificial spots of higher or lower trend values in the raw data. After the homogenization, the areas with insignificant trends were considerably reduced. [ABSTRACT FROM AUTHOR]

Today, it is common knowledge that increased use of renewable energies has a significant impact on reducing greenhouse gas emissions. The most notable types of renewable energies are solar energy and wind energy, whose popularity comes from their prominent features such as cost-effectiveness, stability and easy utilization. The objective of this paper is to perform a technical-economic analysis on combined utilization of solar and wind power in two cities of Qom and Yazd, to conduct a feasibility study on the construction of clean energy producing power plants in these locations. To achieve this objective, we first gather the required data from the national meteorological organization, and then use Homer software to perform technical and economic analyses on the two considered sites. Solar and wind analyses on Qom and Yazd show that both cities have great potential in solar energy generation, but wind speed data indicate that only Qom has the wind characteristics appropriate for wind power generation. Overall, these results indicate that investments on solar energy sector of both cities will be economically justified, but only Qom has the wind characteristics required to make investments on its wind energy sector economic. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1194-1207, 2017 [ABSTRACT FROM AUTHOR]

SUMMARY This study presents a selection of optimal energy alternatives for electrical self-sufficiency in a rural university (Universidad del Istmo, UNISTMO), located in the state of Oaxaca, Mexico and for the electricity supply for a rural community (Gran Piedra) in Santiago, Cuba. The analysis follows a multicriteria approach. It uses a method called compromise programming and takes into account the technical, economical, environmental and social criteria. The hybrid optimization model for electric renewables (HOMER) software was used to generate alternative energy sets through enumerative search, with which decisional matrices were built for each case study. The influence of weighting for each criterion was assessed. In the case of self-sufficiency in UNISTMO, when the decision-making center has a preference for the minimization of equivalent emissions in the life cycle (ESLC), a wind system is suitable. On the other hand, when there is a preference for the minimization of levelized cost of energy, a photovoltaic (PV) system is suitable; both systems connected to the national electrical grid. Obviously, a preference for the minimization of capital cost led to keeping the power supply from the grid. In the case of Gran Piedra, a diesel generator-based system is suitable when the criterion 'capital cost' absorbs 70% or more of the preferences of the decision-making centers. When the preference is less than 70% regardless of the weighting given to other criteria, the best alternatives are those involving renewable technologies, reaching renewable fractions of 75% and 94% in two potential configurations of energetic systems. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]