Journal of Renewable and New Energy
Year:2020 | Volume:7 | Issue:1|Papers Count:15

In this paper, a novel combination of a photovoltaic solar pump system designed to eliminate the water needed for irrigation of arable land. In this survey, efforts have been made to provide a cost-effective design according to the concept of participation of several gardens in the system and setting up the system. The presented system is a good option for areas and fields that are far from the grid and the grid delivery is very costly and very difficult. The study has been carried out with regard to various parameters such as monthly changes in the required power due to radiation changes, changes in the total system voltage in different months based on the lowest temperature and maximum voltage at the effective temperature of the panels per month. This system is designed for grazing irrigation of 5 plots of land each with a total area of 2 hectares around the city of Arak. Then, according to the irrigation period and the area of land, the required amount of water per day is calculated and in the next steps the pump power is chosen and according to the elements of a photovoltaic system, the amount of energy needed to work the pump in each calculation and the level of the solar panels required to supply the system's energy requirements are met. Finally, the presented design has been compared with the design of the most common photovoltaic system which represents better performance and lower cost for the proposed system.

Using of biomass for energy purpose in the path of sustainable energy supply and in response to increasing energy demand can be an effective solution. Biofuel reduces global warming impacts, which is today the main concern of the countries of the world by lowering greenhouse emissions and dependency of fossil fuels. Briquettes and pellets, as solid biofuels, are the most direct way of using energy from biological sources, because they only need a densification process instead of complex thermochemical and biochemical treatments. Densification process by applying pressure and temperature produces fuel briquettes and, which results in elastic and plastic deformations in biomass, increases density in biomass. Moreover energy density and durability in produced solid fuel increases. Creation of solid bridges between particle and mechanical interlocking, to density of its components, is a possible mechanism of particle bonding. Proximate and ultimate analyses can be used to measurement of intrinsic properties of particles such as ash content, volatile matter, fixed carbon, and heating value that can deeply affect on combustion process. Also, fuel briquettes and pellets are qualitatively measured with properties such as density, durability and calorific value. Combustion of solid fuels involves drying mass loss stages, devolatilization and combustion of char. The major problem of solid biofuels is the amount of ash in comparison with coal, which results in fouling and corrosion on equipment. However, different researches can focus on reducing ash problems.

The vortex plate method will determine the velocity at each point of the current without the need for the grid on flow geometry and speed determination in all fluid fields. due to the importance of blade aerodynamic the turbine performance coefficient, for modeling of the airfoil, the Bezier equations are used. the flow around blade-axis wind turbine blade issimulated in two dimensions by computational fluid dynamics such as airfoil and mesh and is used for resolution of fluent, based on finite volume method. also in order toinvestigate the potentials of vortex pages, theresults of the writing code are compared with fluent Fortran and Q-blade which can be simulated using a fuzzy model and correct algorithm. the results obtained from vortex shedding methods show that we have acceptable accuracy compared to the experimental values and leads to vortex plates in low Reynolds number, lift and drag coefficients are more accurate than fluent and Q-Blade software.

Clathrate hydrate is a new technology to store the cold energy in air conditioning systems. These compounds offer a high cold storage density. The phase change temperature of clathrate hydrates is more than water. On the other hand, these compounds offer better heat transfer properties and improved cyclic stability, compared to eutectic salts. These appropriate properties of clathrate hydrates made these compounds as promising potential for cold storage air conditioning systems. In this study, we investigated the refrigerant hydrate formation as a potential to store the cold energy. The equilibrium data reported by researchers are collected and the effect of various additives on their phase equilibria are investigated. A comparison between the dissociation pressure of hydrate formed in presence of some refrigerant are undertaken. Finally, the various methods of hydrate-based refrigeration systems reported in literature are collected along with their advantages and drawbacks.

Remote communities in many countries are in need of dependable and affordable fresh water that must be derived from local brackish water or seawater. Renewable energy from wind, solar, geothermal, or other sources may be necessary when access to grid electricity is limited. This brief focuses primarily on water desalination based on the use of renewable energy. Global water withdrawals amount to around 4, 000 billion m3 per year and in some regions, especially the Middle East and Northern Africa (MENA) – desalination has become the most important source of water for drinking and agriculture. Today’ s global desalinated water production amounts to about 65. 2 million m3 per day (24 billion m3 per year), equivalent to 0. 6% of global water supply. Major desalination technology options are based on thermal processes using both heat and electricity, and membrane technologies using electricity only. The dominant technology is Reverse Osmosis (RO), which accounts for 60% of the global capacity, followed by Multi Stage Flash (MSF), with a 26. 8% share. Renewable technologies that are suited to desalination include solar thermal, solar photovoltaics (PV), wind, and geothermal energy. As electricity storage is still a challenge, combining power generation and water desalination can also be a costeffective option for electricity storage when generation exceeds demand.

Increasing demand for energy and reducing fossil fuels have created the need for clean and reliable energy. Hydrogen-based energy systems are one of the new solutions in the long run. The main challenge of this technology is the production of a large amount of hydrogen from renewable sources. Some of the intermediates and their alloys produce metal hydrides in reaction with hydrogen gas or atom from an electrolyte. The reactive hydride reaction of these metals and their alloys introduces them as a reservoir for hydrogen storage. The nanoscale causes an increase in the rate of hydrogen uptake and hydrogen removal in metals and alloys. The use of milling mills has a wide application in the separation of hydride grains. The Mg and Mg2Ni nanocrystals obtained from milling mills have shown a faster rate of hydrogen uptake than the mass of these particles at a relatively low temperature. Because the surface effects increase and the length of the penetration path is reduced.

The main purpose of this review article is to review and compare how Iran's and Pakistan's energy systems will be transferred to a 100% renewable energy system by 2050. Iran and Pakistan are neighbors and the main source of energy in both countries is fossil fuels. But, Iran has major fossil resources, while Pakistan is an importer of fossil fuels. Therefore, in this article, by reviewing the literature on designing a 100% renewable energy model for Iran and Pakistan, has been attempted to compare the energy transfer paths in these two countries. To simulate a fully sustainable energy system, an approximate hour-by-hour model for both Iran and Pakistan has been used between 2015 and 2050, which includes demand for electricity, seawater desalination and non-energetic industrial gas sectors. The levelised cost of electricity estimating show that renewable resources have the best efficiency and lowest cost among all options for achieving an energy system with a zero-emission of greenhouse gas. The analysis demonstrates that it is possible to carry out this transition from a technical and economic perspective with some measures being vital for achieving this ambition in a cost-effective manner.

Using wind turbines in urban areas is one of the most challenging issues in using wind energy. due to the complex structure of urban areas, the fluid flow turbulence and the change in wind speed in these areas is significant. It is common that vertical axis (Darrieus-Savonius) wind turbines in that operate independently of the wind direction is commonly used. In this research, a comprehensive overview of major studies in this area has been carried out. In addition, challenges of using a variety of vertical axis wind turbines are mentioned. on of the challenge in this topic is using a hybrid wind turbines, with two types of Darrieus and Savonius. Darrieus turbines have high power coefficient, While Savonius turbines have the ability to start very well even at low wind speeds. In this research, it has been studied to make this system more functional and some suggestion have been presented. In order to eliminate the destructive effect of the Savonius turbine rotor on the Darrieus turbine rotor at high wind speeds, a mechanical clutch is proposed for separating these two rotors at high rotational speeds.

In the light of importance of sustainabile development, global warming as well as mortality of Fossil fuel correspondingly using of solar energy be more and more important. Photovoltaiv panel is an application of solar energy resource. A weakness of Photovoltaic panel is efficiency reduction caused by temperature increase. The efficiency of photovoltaic panel decreases by approximately 0. 5% per Kelvin. There are different methods to PV thermal regulation, which the use of Phase change material is more important one. Organic or inorganic compounds that are capable of absorbing and storing large amounts of heat energy are called phase-change materials. Due to the high efficiency and high capicity of phase-change materials in energy storage systems, the use of these materials in recent years has attracted many developed countries. Accordingly, this paper reviewd studies about using PCMs for PV thermal regulation. Considering to the considerable enhancement of the PV performance via application the PCM, the PCMs can be a appropriate solution for the PV performance enhancement.

Oil, the tool that once gave the world the power and technology, today it is ready to annihilate the world, a commodity that has been a tool of power and slavery throughout history. The material that we created using this modern world, but itself is destroying our world. In this paper, attempts have been made to examine the powerlessness of this commodity throughout history, which, as a result, will further understand the painful future that comes with over-consumption of oil. Then, practical solutions to the future of renewable and sustainable energies that rely on three environmental, economic and social factors are to be addressed. In the meantime, solar, biodiesel, hydro and geothermal energy have been investigated, and it has been found that in order to produce 17. 25 per capita electricity per hour in traditional way, it requires 8. 85 × 107 107 tons of coal. If coal is used, the amount of carbon dioxide 091/234 MW will enter. Renewable power generation can provide about 20% of energy demand and reduce more than 40% of greenhouse gas emissions associated with energy production. The amount of power consumed in Iran is 255, 000, 000 MW, with an annual solar power plant of 1898658 MWh and an annual supply of 1846426 MWh of electricity to the network.

One way to increase wind turbine production capacity is to use airfoils with a high coefficient of friction coefficient in wind turbine blades. In airfoils, the coefficient of up and down coefficient depends on the geometry and shape of the airfoil as well as the dependence on the angle of attack and the velocity of wind flow passing through the airfoil. In this study, after introducing important concepts in wind turbines, the E387 airfoil was selected and a new airfoil was designed by modifying and improving the desired airfoil geometry. In the designed airfoil, the ratio of the coefficient of the coefficient to the coefficient of increase was 14. 21% compared to the value of the coefficient of initial coefficient, and the highest coefficient of coefficient of coefficient of coefficient of coefficient for the initial coefficient was 124 and 2. 5 ° . Designed for the new Airfoil, this value is 142 degrees at 4 ° , and in the computation and design of the Q-Blade software, which performs simulations using the momentum and correct algorithm models. Modifies the design parameters with the CMDMS model, which uses a two-stage momentum model for aerodynamic simulation of the torque. Inflatable uses, used.

Solar energy is one of the sustainable and inexpensive energy sources in the world. One of the most important uses of solar energy is generated electricity by using photovoltaic systems. Integrating photovoltaic systems with buildings is one of the favorite plans for engineers and architects. In this study, simulation of electricity generation from three different plans of photovoltaic systems integrated with the building and a photovoltaic installation system on the roof in a residential complex was investigated. The panels used in the simulations are monocrystalline, cadmium telluride and thin film. Due to the different characteristics of the panels, different amounts of electricity is produced by them. The simulation results showed that the plan including monocrystalline solar panel has the highest electricity injection rate (871. 2 MWh / year) into the grid. The integrated system including thin-film modules has the lowest amounts of electricity generation into the network and also the lowest performance factor. Economic calculations showed that using a combination of integrated system and installation on the top roof, it could be possible to return the investment in 3. 65 years. The inflation rate and the purchase price of electricity produced at the power plant play an important role in investing in this area.

FPSO or Floating Production Storage and Offloading platforms are increasingly used to explore deep-seated and offshore waters. In order to realize the improvement and progress in the production process, as well as the generation of electricity in its production phases, it is essential to invest in efficient technologies that reduce the cost and release of carbon dioxide into the atmosphere. From this perspective, ORC has a high potential for energy recovery from the thermal resources of the various FPSO platforms. In this paper, in addition to the baseline, four different scenarios were used to use the exhaust heat output of turbines in the service. The suggestion is more attractive, that two turbines generate power in all production intervals, and exhaust gases from the CO2 turbine as a heating source in the ORC is used. In this way, the heat of exhaust turbines can be used to supply heat and supply of the demand for electricity, and using ORC (with heat recovery) in heat recovery, emissions reduced carbon dioxide. This study showed promising results in using ORC for heat recovery, an average of 22. 5% for reducing fuel consumption and carbon dioxide emissions Lifetime FPSO provides.

Today, with the reduction of fossil fuel consumption in the world, the use of renewable energy has taken on a remarkable role in the world's energy basket. The use of renewable energies and environmentally friendly methods for generating electricity is one of the priorities of today's developed countries. Because of special geographic conditions, Iran has many capacities to use renewable energies, and if new investments can be made, this is best served. In this study, we tried to review the current state of energy and future demands for renewable energy in Iran in order to identify the potential for enhancement of renewable energy technology. The existence of large oil and gas supplies and cheap energy through subsidies in Iran have caused our country to retreat from new energy sources compared to advanced industrial countries. In recent years, the lack of adequate allocation of funds has not allowed large power plants to be built, while, according to the experts in this area, all the Iran's electricity needs can be supplied through solar energy. Such unused capacity will cause the production of electricity in Iran, including the construction and maintenance of power plants will spend tens of billions of dollars of foreign exchange earnings annually. Investing in the new energy industry is an investment for energy independence, and countries that can expand their new energy infrastructure and electricity grid faster in competition for power generation and economic development will be one step ahead of their rivals.

Considering the risk of reducing fossil fuels in the near future and increasing environmental pollution problems, human societies are now struggling to change their supply and demand patterns. With the advancement of technology, the use of renewable resources is considered as a reliable alternative to fossil fuels. Therefore, the role of geothermal resources as one of the most important sources of renewable energy is notably discussed. This energy is introduced as a sustainable resource, with the potential of adaptation as an alternative to fossil fuels. This paper examines the application of geothermal energy in agricultural applications in the world and Iran. At the same time, geothermal energy and its applications are introduced in various sections, especially greenhouses. Then, the conventional parameters and methods of geothermal energy design for use in greenhouses are presented. As a result of these studies, it was determined that 5 methods for heating greenhouses and 2 methods for greenhouse cooling were considered, which should be selected according to the requirements of the applicant unit and the regional conditions. Finally, the situation in Iran is evaluated in utilizing geothermal resources in the agricultural sector.