Sharif Digital Repository

The present study was aimed at developing a model to optimize the sizing of wind turbines according to the region’s wind condition and the capital costs of each part of the turbine. The proposed model, which consists of technical aerodynamic, economic and optimization sub-models, is used to achieve maximum annual energy production by a fixed cost of a single or a number of wind turbines. A cost model has been used to determine the detailed cost of the turbine’s components. The model’s results are presented for two regions in Iran, Khaf and Ahar, and the optimized configurations for a single turbine and a wind farm have been investigated.A case study for the region- Manjil that has some... 

Today, renewable energies such as solar and wind power are replaced to fossil fuel. Wind turbines are two categories; horizontal axis and vertical axis. Vertical axis turbines are not dependent on wind direction and since equipments are installed at the bottom of these turbine towers, maintenance is easy. Among vertical axis turbines, performance of darrieus turbine is better. The aim of this thesis is, analysis and preliminary designing of 1-kilowatt darrieus wind turbine, based on climate of the country, for using in urban environments or areas where there is no economic justification for development of power grid systems. In this regard, statistical data base is made up of vertical axis... 

Many researchers believe that the production of knowledge is a cumulative process based on past learning, and on the other hand, deepening in a specialized knowledge causes fundamental changes in that field. so to justify the existing relationships, the concept of knowledge spillover is taken into consideration. Knowledge spillover means that technologies can benefit from knowledge originating in other technologies. Our goal in this research is to identify the mechanisms and type of knowledge that can affect the flow between different industries and countries. With the increasing need of the countries of the world for energy and the environmental hazards of fossil energies, an important... 

Nowadays, because high global demand for energy has led to the extensive use of fossil fuels with numerous unintended consequences such as air pollution and greenhouse effect, research and development around optimization of energy infrastructure has become much more important. Consequently, many scientific approaches have been applied to replace fossil fuels with renewable natural energy resources. One of the renewable energy types that fewer papers have been published about it, is the enormous energy of Marine currents. The origin of this energy is mostly tidal effect, or ocean currents that are available in most of oceans and seas around the planet earth. The most important criteria for... 

According to the Government policy in order to make targeted subsidies and apply it on various sectors in the industrial, commercial, agricultural, household and etc. changes in the energy supply needed resources in this section are required to appear. The agriculture sector is one of the most important parts of the food production is the production of security and health product. In this regard, the production of greenhouse products in terms of the use of high yielding varieties, production of the off-season, better control factors in production and reduce water consumption has increased drastically. The main source of supply in the internal energy of the greenhouse heating is mainly fossil... 

Ever-increasing energy consumption and consequent extensive greenhouse gas (GHG) emissions are two major urgent problems faced by all human beings in the 21st century. As a major contributor, the energy production section appears to be the most suitable field where further improvements could be explored to tackle these problems. Multi carrier energy system is a typical type of next generation energy production technology with higher energy efficiency and lower/zero GHG emissions. The conversion of energy between different carriers establishes a coupling of the corresponding power flows resulting in system interactions. The investigation of such phenomena requires the development of tools for... 

Nowadays, classic energy supply systems are rapidly shifting towards more efficient, with less pollution, and more economic energy systems. In the meantime, the growing dependence of human activities on energy sources and the reduction of fossil fuels resources as the main source of energy supply at present time, has led to fundamental changes in the energy policy of communities. The use of distributed power generation systems utilizing renewable energy sources is one of the solutions that have been proposed in this regard. This research aims to develop a local energy supply network for a specific rural district using energy sources in place, so that the area is energy self-sufficient and... 

The concept of smart grid to realize the triple goals of economy, reliability and environmental improvements has taken advantage of modern equipment and new structures. Beside these goals smart grids seek to increase the level of penetration of renewable resources for environmental improvement. On the other hand, increase in dispersed products and problems resulting from increasing these non-dispatchable resources thus led the researches to design a new structure called microgrid. Microgrid improves the reliability of these resources and facilities their uses. But uncertainty and intermittency in producing renewable energy resources are among the main challenges facing these microgrids.... 

Considering the continuous growth of renewable energy sources in electric grids, the importance of utilizing simple, generic, and upgradable models for different network stability studies is increasing. In recent years, generic and standard wind turbine models for transient and short-term frequency and voltage stability studies have been developed. In this regard, researchers are still working on promotion of the generic models, especially to expand them for unbalanced transient studies, improve the transient response, and include inertia response. In this thesis, different methods for generic modeling of wind turbines are surveyed and the development procedure of WECC and IEC generic model... 

Renewable resources, because of their compatibility with the environment, accessibility, and low cost of operation, have become the center of unprecedented attention. Since the output of these resources cannot be predicted accurately, they are usually implemented in microgrids with conventional generating units and energy storage systems.Furthermore, distribution networks are integral parts of power systems, and many studies have been conducted in order to improve them. Because of high investment and operation costs of distribution networks and environmental concerns, it is necessary to conduct meticulous economic studies so that with proper investments, profitable opportunities are provided... 

Emission of CO2 and its diffusion into atmosphere is associated with negative effects on the environmental such as Green House Gases effect. Various techniques of CO2 Capture in energy conversion and processing plant are investigated. A method of CO2 Capture could be based on utilization of solar energy for producing methanol. Basic design of such a system and feasibility analysis of developing that system has been considered on the subject of the present research work. Basic design and commercial feasibility of the system producing methanol through capturing CO2 from exhaust gases of a power plant and hydrogen produced by using solar energy have done such an integrated system. The main... 

Two major challenges facing countries all around the world are the demand for renewable energy resources and treatment of large quantities of industrial and household wastewaters. One of the new and environmentally acceptable methods to produce green energy is Microbial Fuel Cells (MFCs), which has been noted by many researchers in recent years. MFC is a new technology which has the ability to produce green energy along with treatment of wastewater stream, based on oxidation of organic maters through microbial metabolism. In this study we investigated the effects of different cathode chamber parameters on operation and efficiency of a two chamber MFC at laboratory scale. These parameters... 

There is a need for renewable energy sources to be more feasible. The purpose of this project is to develop a compact device that is able to harvest wind energy and transform it into electrical energy using the concept of vortex shedding. When calibrated correctly, the vortex shedding will induce resonant oscillation. Electricity would be collected from this oscillation using a magnet and coil assembly. This method was proven to work in water, but has not been applied to air currents. Our group designed and built a small-scale prototype to be tested in closed circuit wind tunnel. The wind harvester works at a moderate wind range of 3 to 5 m/s. Data was collected on the amplitude and... 

The operating conditions of the battery in renewable energy systems affect its electrochemical behavior and degradation process. Recent research mainly estimates battery lifetime through conventional methods such as counting the number of equivalent battery life cycles or based on simple experimental models that may lead to optimistic predictions in battery service period. In this study, a reduced-order thermoelectrochemical-aging battery model is developed for the application of renewable energy systems and the battery degradation analysis is investigated by this model. The proposed microscopic model evaluates the effect of battery operating conditions such as state of charge, current and... 

By entering the concepts of transactive energy systems, microgrids and peer-to-peer networks into the local energy market, it has made it possible to implement local energy market in the microgrids more than ever. In transactive energy systems, with the elimination of the intermediate entity, exchanges take place directly between the different parts of the system, which results in increased system flexibility and reduced system costs. In this study, by applying blockchains in local energy market and in micro-grids and transactive energy systems, a framework is proposed to implement local energy market in an energy micro-grid based on blockchain. By using blockchain features and structure,... 

The increasing variability of renewables and volatile chronological net-load in modern smart grids engenders significant operational risks of an uncertain sufficiency of flexible capacity. Assessing the operational flexibility of the grid with high penetration of renewable resources remains an issue of critical importance. Operational flexibility insufficiency may bring about two major problems: 1) there may exist no feasible solution for operation under uncertain conditions due to insufficient available flexibility capacity;2) even if the solution feasibility criterion is ensured, dispatch limitations of the flexible resources may force the system operating point to deviate from the optimal... 

The objective of the present study is the development of an optimization model to identify the best configuration of renewable-based integrated energy systems. The system includes a combination of renewable energy systems such as wind, solar, hydropower and hydrogen production, storage facilities, and conventional fossil-fuel generators. The developed tool consists of various modules where water-heating assumes the utilization of waste energy as an option. Furthermore, the application, which is demonstrated for a case study in Tehran has been considered. The power exchange with the distribution network and injection of hydrogen produced from excess renewable sources into gas network are...