Journal of Renewable and New Energy
Year:2021 | Volume:7 | Issue:2|Papers Count:15

In recent years, increase of electricity consuming, reduction of fossil resources and as well as attention to environmental issues have led to increase producing of energy by photovoltaic systems. Floating solar power plants are one of the approaches for using of solar photovoltaics has been strongly developed because of more efficiency due to water cooling and the reduction of water evaporation due to expanding on dams and canals. In present study, to introduction the technology of floating solar power plants, the advantages and disadvantages of different solar power plants, especially the floating solar power plant, the mechanism of floating solar power plants and the equipment related of them have been investigated. A thorough study of the floating solar power plants in the world has also been done to investigate the future and market of floating solar power plants. In this regard, the main actors and the active countries in this field have been studied. Considering the significant benefits of floating solar power plants compared to other solar power plants, as well as the study of its dependent market, it is expected that the launch of these types of power plants in the future years around the world will grow tangentially. In Iran, due to the presence of dams, lakes and sea from the north to the south, and the proper radiation of the sun on their surface, there is a potential for the development of these types of power plants.

Many Efforts have been made in order to use new and renewable energy instead of fossil fuels and as a supply of the needed clean energy. One of the most interesting options which attracts researches’ attention, is one of the most common element in the earth, Hydrogen. For using the hydrogen as a source of energy, there are two important points which should be considered carefully, first is the technology of production of hydrogen and second the storage of hydrogen. In this article the hydrogen adsorbent materials are introduced. The metallic hybrids, Nitrogen based materials, Mg-based materials and carbon based materials are four main groups of hydrogen storage materials that attracts many attentions. Faradic parameter described theoretically the capability of hydrogen storage. Based on the before investigation, high current density, lower voltage and high discharge rate in carbon based materials especially in carbon nano tubes increase the capability of hydrogen storage. Increasing the storage capacity of hydrogen will help human being to access the clean fuel for all uses in energy.

The value of radiation energy is considered to be the main component of the design of clean energy devices. Due to the fact that this amount is not measured or in some cases the radiation station may not be available in Iran, so it is necessary to estimate this component. In this study, Kerman and Yazd were selected as the regions with the maximum potential of solar energy. Then Artificial Neural Network (ANN) and Support Vector Machine (SVM) capabilities were evaluated in solar energy estimation. For this purpose, the daily data of 25 years (1992-2017) including maximum temperature, mean temperature, relative humidity, sunshine hours and solar radiation were collected at the synoptic stations of these regions. To evaluate the performance of models, common evaluation statistics were used. The results showed that at the Yazd station, in the ANN method, the lowest values of RMSE, MAE and the highest values of IA and R2 were 2. 381, 1. 760, 0. 869, and 0. 962, respectively. These values at Kerman Station are equal to 2. 708, 2. 050, 0. 945 and 0. 810, respectively. In the SVM method, the lowest values of RMSE, MAE and the highest values of IA and R2 at the Yazd station were 2. 028, 1. 540, 0. 901 and 0. 973, respectively, and at Kerman station were 2. 407, 1. 896, 0. 956 and 0. 846, respectively. Overall, the efficiency of the SVM method in both regions was more accurate than the ANN method.

A great amount of global energy is consumed for building heating and cooling. Renewable energies are considered to prevent pollution made by fossil fuel in the building industry. Ground source heat pumps are known as a technology to supply heating and cooling demand in buildings. In this paper, the energy demand for residential cooling and heating is calculated in Iran in 2030. Then, two scenarios are discussed to supply the needed energy. In the first scenario, the energy is supplied by air source heat pumps (split units), and the second scenario considered ground source heat pumps. The result indicates that not only the second scenario can cause 8736. 7 million cubic meters of natural gas and prevent 59. 6 million tonnes of air pollutants, but also the country can export 7028 million $ electricity to its neighbors. Also, the total cost for the country to supply the energy need is reduced by 49994 million dollars.

A comprehensive energy analysis is reported for the west Azerbaijan gas company sport and cultural complex and swimming pool. Energy analysis are used to characterize the energy losses in the complex and estimate complex energy performance. The primary objectives of this paper are to analyze the west Azerbaijan gas company sport and cultural complex and swimming pool components to identify and quantify the sites having largest energy losses. A computer modeling program using Design builder software is developed to model the complex. The results showed that the main source of the energy losses is the swimming pool due to the surface evaporation. It has been demonstrated that in this specific case the improvement of the sport and cultural complex and swimming pool and the optimization of the performances of the existing systems can reduce energy consumption at least 20% per year and save on costs. Finally, the authors have suggested using the solar PV system for electricity generation and solar flat plate collector for swimming pool water heating in the west Azerbaijan gas company sport and cultural complex.

The growing need for energy in all dimensions, especially in residential and office use, has made the need to use renewable energy sources a vital issue. It is generally assumed that Light Shelf is a useful tool for daylight utilization. Therefore, most green buildings benefit from this technology without a realistic assessment. The purpose of this study is to objectively investigate the ability of Light Shelf to improve daylight as well as visual comfort by experimental research in Guilan. In this experimental study, the Scale Model on 1: 5 scale was built and investigated the effects of a Light Shelf system that uses different illumination (light intensity) interiors with outside amount of light while resizing the interior and exterior Light Shelf size. The data were analyzed statistically and the performance of Light Shelf in different ways was analyzed. The results show that in 73% times, the Light Shelf can increase daylight in the depth. Contrary to the notion that the use of optical light could reduce the intensity of light and subsequently reduce grey near the window, it was found that the use of this system could only 43% reduce the intensity of light and grey near the window.

Population growth and the country's need to move towards development, requires the optimal use of energy. Nowadays, the current energy systems of the country, use fossil fuels to meet this need. The limitations and exhaustibility of fossil fuels, the creation of various types of environmental pollutions, greenhouse gas emissions and global warming, that indicates the obvious disadvantages of the use of non-renewable energies, further underscores the need for faster movement towards using renewable energies. The lack of an efficient and optimal energy model and a defect in the structure of the energy systems of the country, is one of the main reasons why in spite of the awareness of the problems of non-renewable energies and its harmfulness it is still we use these energy baskets. Smart energy systems, considering each of the three main energy systems (electricity, heat, and transmission) interconnect each other, examines the energy system as a whole to provide an appropriate solution to meet the demand as well as the need for each of its subset sectors, with the highest technical and economic justification. So, in this paper, after expressing the theoretical foundations of smart energy systems and examining the background of its formation and its use, the main problem (The lack of proportionality between increasing population and increasing energy consumption in pursuit of sustainable development) has been studied, till by exploring the methods of doing this work, a smooth path to development in the use of renewable energies to be founded.

All energy scenarios show that the energy supply approach is shifting to renewable energy, in particular energy from biofuels. On the other hand, in the context of this type of energy, water which is a limiting factor in the discussion of agricultural products, arises. In this research, using the water footprint index, the amount of water consumed for the production of each energy unit was calculated from wheat biomass. In this regard, six provinces of the country with the highest production value were selected. The purpose of this study was to determine the most desirable province for producing bioenergy from wheat biomass from the perspective of the water footprint index. The results of this study showed that Golestan, Kermanshah, Ardebil, Khuzestan, Fars and Khorasan Razavi provinces devoted 25. 1, 33, 35. 5, 39. 4, 43. 9 and 83. 7 cubic meter of water per GJ, respectively and this values showed the priority to produce bioenergy from wheat biomass. In other words, from the perspective of the water footprint, the productivity of bioenergy production in Golestan province is more than other provinces. Therefore, this situation has created an advantage for the use of wheat biomass in the province.

The existence of a successful internal and global experience in establishing an energy management system, based on ISO 50001: 2018, is an acceptable method for organizations to reduce their energy as well as environmental costs. In this standard, the methodology to promote energy management in organizations is presented. In a sense, improving energy performance leads to a reduction in consumption and, consequently, the energy costs are organized as such. On the other hand, as well as raising competitiveness of the organization, and improving its profitability, it also covers part of their environmental commitments. This standard creates a framework for a systematic energy management in industrial, commercial and governmental organizations/institutions. The energy baselines, performance indicators, targets and energy performance monitoring are important parts of this standard. In this study, using actual energy consumption data and by identifying effective factors influencing on this parameter, a model has been developed for targeting, performance monitoring and compilation energy bases in an administrative building in Tehran. Results show that the proposed model/methodology and its information can be used in any similar building in any geographic region.

Due to the importance and effects of energy systems planning on environmental parameters and living standards, it is necessary to change these systems to achieve environmental benefits, improve the energy security, diversifying the energy basket, flexibility in energy exchanges between energy system components and etc. For this purpose, the energy supply of the society requires to move toward the smart energy system. These systems are a set of smart gas, heat and electricity grids with different technologies and accessibility that are planned and managed to work together. One of the most important features of smart energy systems is to use and increase the share of renewable energy sources. In the literature investigated in this field revealed that, the main criteria are the amount of power inputs and its cost per unit, mainly with the aim of reducing costs and decreasing the carbon dioxide emissions, maximizing the share of renewable resources. For formulating and modelling of such systems the conventional mathematical programming methods or metaheuristic methods are used. As well as the importance of these systems and the concepts of 100 % renewables are proposed by most of the developed countries next 30-years.

Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. The purpose of this study was investigation the feasibility of biogas production from domestic wastewater in an industrial unit. In this research, firstly the characteristics, production sources, importance, usage and models of biogas production systems were studied. Then, the calculations related to the amount of biogas production of the mentioned industry were performed based on influent and effluent wastewater flow rate and biological tests. According to the results, because of the low flow rate of influent wastewater, the amount of produced biogas production was not considerable and it could not supply the heating/cooling demand of the industrial unit and only the electrical energy of the lighting of the area will be supplied by the energy of produced biogas. However, in terms of reducing greenhouse gas emissions, the production of liquid and solid contaminated solid fertilizers can be considered. However, if the wastewater is added to the wastewater of adjacent animal husbandry, poultry houses and slaughterhouses and the flow reaches at least 1300 m3 per day, the biogas production will be considerable and economical.

Given the increasing development of renewable energies and their worldwide growing significance, specifically in developing countries such as Iran, focusing on the ways of storing this kind of energy, as the main issue in this area, is a priority. Since Renewable energy production is strongly dependent on the climate conditions, the full time reliance on them for providing power and other applications is not possible and therefore, for the moment, responding to the whole energy demand, by solely depending on renewable energy is not an option. Storing energy contributes to keeping the balance between demanding and providing energy, by immediate discharge of it in the time of need. Among various Storing solutions, water, due to its capability of converting potential energy to kinetic energy, has the capacity of storing and discharging vast amount of energy to facing the demand. The present work, describes different methods and solutions of utilizing water as energy storage. Some of these methods have been used for a long time, while some others are considered to be fairly novel with a long way ahead to become fully developed and commercialized.

Solar stills have been welcomed by many researchers due to the very low cost of manufacturing and the lack of complicated mechanisms, as well as the need for service and maintenance. Extensive researches, including modeling, optimization, combination of mechanisms, economic analysis, and localization of various active and passive models of these devices has been carried out to date. The results of these researches, together with the high potential of these devices to implement new ideas on them, led to the construction and testing of a wide range of different types of models. Most of the researches have been conducted in Asian and African countries with hot and dry weather and has always been emphasized on the appropriateness of these devices for using in remote areas. Researches are currently under way on these devices in most parts of the world. In the present study, experimental researches on these devices has been reviewed. This study shows that the focus is on the use of new and cost effective methods to increase the output and thermal efficiency of devices, which differ in the active and passive type devices.

In this study, environmental and sustainability aspects of six sources of hydrogen production (biomass, geothermal, hydro, nuclear, solar and wind), four systems of hydrogen production (biological, electrical, photonic and thermal) and five sources of hydrogen storage (chemical hydrides, compressed gas, cryogenic liquids, metal hydrides and nanomaterials) are compared. Five sustainability criteria (economic, environmental, social and technical dimensions and reliability) and four environmental performance criteria (greenhouse gas emissions, land use, water dischaqrge quality and solid waste generation) of the selected options are ranged from 0 to 10 points, where 10 indicates the best and 0 weak indicates the lowest performance. From the sustainability point of view, solar and geothermal sources, with ratings of 7. 4 and 4. 6, have the highest and lowest performances, respectively. Electrical and photonic systems with 7. 6 and 5. 4 points have the highest and lowest performances in hydrogen production, respectively. Nanomaterials and cryogenic liquids with 8. 4 and 3. 4 points have the highest and lowest performances in hydrogen storage, respectively. Electrical hydrogen production based on solar energy according with the nanomaterial storage system are the most sustainable and best options from the environmental point of view.

The downward trend of fossil fuels and the need to replace them with new energy sources is one of the major concerns in the energy field. On the other hand, the increase in environmental pollutants has limited the use of fossil fuels. Therefore, new energy sources that are environmentally friendly and their consumption rates are equal to their production rates have attracted the attention of researchers. One of these endless sources is the solar thermal energy. In recent years, the use of solar energy in various forms and ways has attracted the attention of researchers. Meanwhile, solar turbine cycles have received much attention in recent years and their use has attracted the attention of many countries. In this paper, the performance of new configuration types available in solar turbine cycles is studied. These classifications include straight atmospheric and pressurized cycles. On the other hand, hybrid cycles based on solar turbines have also been studied. Studies show that the use of solar turbine cycles significantly reduces air pollution in addition to reducing fuel consumption.