Journal of Renewable and New Energy
Year:2019 | Volume:6 | Issue:1|Papers Count:15

This paper proposes a new method for sizing a residential on-grid PV battery systems based on peak of electricity grid. Nowadays PV battery systems are usually connected to the grid and renewable electricity generation considered as backup. Minimizing cost is one of the most important goals for this systems. For obtaining electricity demand a residential section simulated by HOMER software. According to announced peak time of power gird, electricity demand in peak time is calculated. Maximum demand in peak time provides Battery and PV size. Since the electricity provides with this system is expensive using PV battery system is reasonable.

Wind power is an important parameter for estimating the potential of a wind farm; it is used to compare different sites. In this study, wind power estimation under four different regions of Iran was investigated. For this purpose, the wind data of the Mayan, Bardsir, Morche Khort and Khash have been recorded at a time interval of 10 minutes per year. The algebraic and graphical methods were used to estimate the constants of the Weibull function, which were used to determine the wind power in the selected regions. The Weibull function used in this study is a two-variable function. After determining the Weibull constants, the wind power was determined. Six types of turbines with different powers and heights were used to estimate the power output. The results showed that in the selected cities, using wind turbines with variable power, which were required low wind speeds to start, could be producing electricity. The Mayan station is the most desirable space to install the wind farm.

Selecting the type of energy for electricity and power generation depends on the policies of the related country. Due to the adoption of stringent environmental laws and also because of the energy crisis, currently the development of renewable energies for countries especially industrial ones are paramount of significant. Iran is one of the largest producers and exporters of petroleum oil and natural gas in the world. Because of this, development of renewable energies did not attract considerable attention during the past decades. Though several researches were done by Iranian researchers to investigate the current status and prospects of renewable energies, very little literature has been found on the problems and limitations faced for renewable energy development. Therefore, the main purpose of this work in addition to report of the potential ofrenewable energies production in Iran such as wind energy, solar energy, hydropower energy, geothermal energy, biomass energy, biofuel energy and tidal and wave energies is to provide technical support and policy tools to address some barriers facing the development and utilization of renewable energies in Iran.

Climatic regions and different weather conditions in various seasons of a year, made humans present different solutions for creating the best thermal comfort they can achieve. On the other hand, today fossil fuels and their pollutions brought the problems which forced mankind to make use of renewable energies and passive thermal systems. With a research in spatial structure and the frame of traditional houses one can observe various solutions in using architectural elements and patterns in accordance with passive thermal and cooling; through which comfort stability in architecture will result in dormant development in saving the energies and resources. Thus, the present paper tries to study physical-spatial structure of the traditional architectural houses of Tabriz, and their application and usage in passive cooling and thermal systems in order to create thermal comfort in traditional houses is to be analyzed and interpreted. The research method is descriptive analysis and to attain information the tools of library and field survey are taken usage of. The results indicate that the traditional architects of Tabriz used passive thermal and cooling systems considering the climatic conditions of regions and using renewable energies attempted to apply some patterns and solutions which makes thermal comfort for the residents in the cold and warm seasons. The cold climate of Tabriz reinforces the importance of utilizing sun’ s energy, thus the house’ s place and direction, building sun-directed windows as well as using thermal capacity of the soil and materials was in priorities of the architects.

The increasing demand for electricity and the cost of using fossil fuels has led to the use of renewable resources and the development of clean energy as a means of securing energy and counteracting the negative effects of climate change. Consequently, the presence of renewable energies has increased the complexity of planning for electricity supply, which is one of the most important issues in the energy supply chain. In this paper, we present a two-objective mixed-integer linear programming model that has environmental and economic objectives, so that we can measure the impact of the use of renewable resources on the amount Earnings from energy sales, polluting emissions and fuel consumption of power plants. Since the proposed model follows two objectives, the ε-constraint method is used to obtain Pareto solutions. Finally, according to the solutions, we have concluded that high capacity plants have a larger share in supplying the grid demand either with an economic approach or with an environmental approach, and low capacity power plants are only used to increase network reliability and to cope with fluctuations in demand. At the same time, the use of large-scale renewable resources, in addition to reducing emissions, will increase the profits from the sale of electricity. In addition, the results show that the development of the use of microgrids and distributed generation is a suitable approach for supplying electricity demand.

Solar radiation use for drying is one of the oldest applications of solar energy. The high availability of solar energy and the rapid reduction of fossil fuels have attracted much attention to developing large-scale solar systems. An efficient dryer is able to increase the quality and quantity of the product and reduce the drying time. In fact, reducing energy consumption is an effective way to reduce costs. In general, solar dryers are low capacity equipment which made based on empirical and quasi-experimental data and theoretical designs. Generally, the drying sector is one of the major energy consumers in the world. Considering the growth of the energy crisis, reducing energy consumption in this sector by using solar energy can guarantee the containment of this global crisis. One of the biggest benefits of solar energy is its endlessness and its full availability, but its disadvantages can be the absence of this energy during night and difference in its amount in different hours of the day. Design of hybrid solar dryers and using of energy saving batteries containing phase change material can be used to solve the above mentioned disadvantages. To solve this problem, energy-saving batteries containing phase-change material can be used to store additional daily heat and use it during the night. In this paper, different drying methods and a different kinds of solar dryers will be described. The special solar panels and solar complexes used in drying and the methods of connecting different solar dryers are also reviewed. The latest applied examples are also presented.

In recent years, polymer solar cells (PSCs) have attracted a great deal of attention due to their low fabrication cost, simplicity of fabrication, light weight and high flexibility. However, power conversion efficiency (PCE) of PSCs is low (about 10%) and should be enhanced before commercialization. PCE of these devices could be improved by enhancing charge carrier collections at electrodes. Transparent conductive oxides (TCOs) have been considered as the promising electron transporting layer in construction of PSCs in order to enhance the PCE of these devices by overcoming the charge carrier recombination. Zinc oxide (ZnO) is a suitable candidate to be used in PSCs due to its high electron mobility, low cost, ease of synthesis methods, high transparency in the visible range and high electrical conductivity. Among the various morphologies, ZnO nanorods have shown strong impacts on the photovoltaic performance of PSCs due to providing direct paths for electrons transfer. In this review article, the influences of ZnO nanorods on the photovoltaic parameters of PSCs as electron transporting layer have been investigated and some of the most important methods for synthesis of ZnO nanorodshave been introduced.

This paper presents the application of shallow geothermal energy for direct use in the world, and a research background has been reviewed by 2015. The distribution of thermal energy used is approximately 55. 3% for terrestrial thermal pumps, 20. 3% for water treatment, 15% for space heating, 4. 5% for greenhouses and outdoor heating, 2% for Aquaculture ponds and crematorium heating, 1. 8% for heating industrial processes, 0. 4% for melting and cooling, 0. 4% for drying agricultural products and 0. 3% for other uses. An annual energy savings of 350 million barrels of oil will prevent the release of 46 million tons of carbon and 148 million tons of CO2 in space. In the following, a brief review of the creation of a shallow geothermal energy market is presented. One of the methods in Barcelona, Spain, is to create a GIS framework for a spatial database and store the main information needed to manage SGE systems such as groundwater velocity, thermal conductivity or thermal heat capacity, and a set of GIS tools to define. Implementation and control. The heat exchange rate and thermal impairment are calculated on the basis of the analytical solutions of porous heat transfer equation.

In this study, two of the most popular power generation cycles are analyzed using EES (Engineering Equation Solver). Cycles are evaluated by their efficiencies based on receiving different gas temperatures extracted from a Gorgo-flame cement rotary kiln. Results show that employing CHP technology in cement production plants will efficiently optimizes energy consumptions beside its effectiveness in decreasing environmental pollutions. Based on the obtained results, the steam cycle was more efficient and saves more amounts of energy. In study the efficiency of the cycles, the difference is observed between 5-20% at the same temperature.

Mortality of Fossil fuels, sustainable development and environmental problems caused by the use of fossil fuels, on the one hand, and the renewables of new energy sources on the other, have led the world to develop renewable energy. Geothermal energy has significant advantages over other renewable energies, such as lack of dependence on weather conditions, sustainability and permanence, high utilization in most areas, and high thermal efficiency. At present, the installed capacity of geothermal energy for power generation by end of 2017 will reach 14060 MW and direct use will reach 70329 GW by the end of 2015. In this study, according to the growth in using of this energy of the last few years, has been predicted to achieve the global capacity of installed electricity to 20 GW (0. 532% of the world's total electricity consumption) by 2030. The use of geothermal energy to produce 175. 25 TWh of electricity makes it unnecessary to use significant amounts of different fossil fuels (Coal: 8. 185×1010 Kg, Natural Gas: 4/975×1010 m3 and Oil: 2. 8×108 barrel). If these fossil fuels were used to produce the same amount of electricity, much carbon dioxide would enter the atmosphere (by using Coal: 234. 091×106 tone CO2, Natural Gas: 97. 957×106 tone CO2 and Oil: 121. 158×106 CO2).

The goal of this study is to evaluate a gas and solar power plants (photovoltaic) grid-connected in Ahvaz city, Iran. The results showed that the solar power plant has more economic advantages than gas power plants. A review of the scenarios concerning the replacement of the guaranteed purchase price of the solar power plant showed that even a 50% reduction in the guaranteed power purchase price did not make the project non-economic. In this case, a big value of NPV (about 68 billion rials) has been lost but the return on investment (22. 8%) would be reasonable. Of course, it should be noted that this is the most pessimistic case when using the project. Comparison on capital returns for a solar power plant, which is 30% of its guaranteed purchase price (4. 2 years) was reduced, and the same factor for the gas plant (2. 5 years in Table 5) gives us the choice of the solar power plant. The results of sensitivity analysis showed that the electricty price is more sesitive that other two economic factors. Using of solar power plants because of the microstats crisis in recent years in this region, can help to implement this method and increase the benefits of this environmental technique.

The fuel cell system is one of the leading clean energy technologies which the interests in its applications are increasing. Since reliability and availability are important indicators to evaluate systems and equipment performance, in this paper reliability and availability of the direct methanol fuel cell is calculated based on the Markov chain approach. For this purpose, after determining the failure rate of each component of the system, the reliability is calculated as a function of time. Also, the Markov chain and simulation in the RAM commander software results indicate that the direct methanol fuel cell is available more than 99 percent of the time. Finally, it was found that the system was 96 percent of the time at full capacity, more than 3 percent at half capacity and less than 1 percent inactive.

According to definitions, external costs are the harmful results of economic activities. This costs represent as social and environmental costs. In the other words, producing a product is attendant with some costs for environment and this cost is not calculated in final price of that product. Paying no attention to this external costs, cause the destructive effects on environment and natural resources. In the energy sector of country, external costs are being imposed some costs on society and environment and cause water and air pollution and reduce the level of the freshwater. Replacing renewable energies can reduce this costs. Based on recent studies, external cost of combined cycle power plants is less the others. According to potential of wind, solar, biomass and geothermal energy in Iran, we can improve our level in renewable energies in future. Not only the environmental costs of renewable energy is very low but also the water footprint in solar and wind power is less than other power plant.

Water is vital for human life and supplying healthy drinking water is essential. Producing agricultural crops and food without water is not possible. Drought in the past years in the country makes it more necessary to pay attention to the proper use of water resources and saving. Disinfection is necessary for cleaning water and an appropriate solution to reduce water consumption by recycling polluted water to the consumption cycle. Many human and plant pathogens such as bacteria, fungi, Protozoa and viruses can contaminate water, but heat is an effective way to eliminate or deactivate all of them. The sun as a free, accessible, abundant, clean and stable source can be used for water disinfection. This issue can be considered with regard due to the potential of Iran for receiving solar energy. The development and improvement of solar collectors has led researchers to utilize them for disinfection. In this study, different solar collectors used in water disinfection were introduced and their performance was investigated. More attention of communities to the health of water and food, focusing on organic products and free of harmful and chemical substances, the seriousness of environmental issues, pollutants reduction necessity, reliance on sustainable energy sources and the use of the country potential promise a bright future for water disinfection with solar energy.

The increase in electricity demand, the rapid reduction of fossil fuels, as well as environmental concerns around the world, have led to the expansion of large-scale photovoltaic power plants. Floating solar system is a new design for photovoltaic power plants which are usually installed on freshwaters such as natural lakes or dams. This technology has attracted the wide attention since 2007. Medium and large-scale floating photovoltaic power plants are installed in several countries, such as Japan, South Korea, India and the United States. Considering the advantages of installing these systems, including reducing evaporation, using these systems in arid and semiarid areas can be a solution to reduce the water crisis. In this article, a review of the articles on the energy generation of floating photovoltaic systems and their efficiency has been presented. Then, the impact of using the system on reducing evaporation and reducing greenhouse gas emissions, as well as studying the economic issues of these systems has been studied. The results indicate that the efficiency of floating photovoltaic systems is about 12% higher than ground-mounted photovoltaic systems. Also, these floating systems can reduce surface water evaporation up to 90%.