Sharif Digital Repository

Trends of energy consumption and global warming, air pollution, Greenhouse gas emission, depletion of fossil energy resourcec and the rise in costs of fossil resources, indicate that renewable energies are reliable alternative in energy supply systems. The purpose of the project is to investigate the contribution of renewable energy to meeting energy demand of housing units. Household energy system consists of various parts which do intreract with each other. Total household energy system may be represented with the help of reference energy system in order to consider the effect of changes in one part on the other sections. In this regard, the reference diagram of household energy supply... 

In majority of the (standalone or grid-connected) PV Systems, predefined rule-based algorithms are utilized in order to manage and control the flow of power. The function of these algorithms is to send the generated energy from solar panels either to load for consumption, or to battery for storage, or to the grid for sale. Their performance is based on predefined instructions and regardless of load change and consumption patterns. Therefore the total efficiency of these systems depend greately upon individual user’s load type and consumption pattern. In current research, an optimum and dynamic energy management algorithm is proposed using dynamic programming (DP) method, in order to increase... 

Photovoltaic phenomena is the base of Photovoltaic cells technology that can transform the solar insolation to electricity directly. In this transformation, the solar insolation intensity is the important factor to increase the performance of the Photovoltaic cells but one of the biggest barriers in the extension way of this technology is its more cost that need to be decrease. Concentration of solar radiation method is the best way to increase the performance of Photovoltaic systems and decrease its initial cost. At this project a novel structure of solar parabolic through concentrator is investigated experimentally and analytically. The usage of Thermoelectric module with Photovoltaic... 

In the present thesis, A Computer software has been developed to evaluate technical and economic aspects of photovoltaic systems, off-grid and on-grid configuration, in urban areas where the electricity grid is accessible. As a case study the building of Energy Engineering faculty with annual demand of electricity in lighting section equals to 80048 kWh was considered. Regarding incident radiation and PV system characteristics with the aid of utilizability concept, a technical evaluation has been performed then life-cycle saving index was considered as a criterion for choosing an optimum nominal size of the system. Results show that for current electricity tariff of educational buildings ... 

Given the population growth in the world and in dire need of electricity and to reduce pollution and moving toward sustainable development, renewable energy has special importance in the world. Iran, with 300 days of sunshine a year is one of the countries with high potential in the field of solar energy but for various reasons, solar energy has no significant role in our energy portfolio. Considering the purchase of solar power by the government, reduce solar electricity costs and payback time of the factors that could make greater use of this energy. In this projects using light splitting method, in addition to reducing cell area used, by removing a significant portion of the sun's rays... 

Nowadays energy consumption increases in our daily life and incredibly enhancement of growth rate can be seen recent years. Hence, the use of renewable energy is prioritized. Solar energy is one of the choices because it is free and available. In this research, it has been tried to get electrical and thermal power at a reasonable cost both during the day and night. The system is equipped with a linear parabolic concentrator with a collector installed in the center of the concentrator which has been installed on its faces photovoltaic cells and thermoelectric modules, and five different systems have been tested with different components. Also, the paraffin has been used as a phase change... 

Nowadays, microgrids which comprise decentralized generation (DG) have attracted considerable attention. Establishment of DG-based microgrids that are normally connected to the main grid, is a practical method to reduce the costs of power outage and to increase the electricity supply reliability. The aim of this thesis is optimum planning of a microgrid containing wind turbines, photovoltaic systems and diesel generators, considering both the grid-connected and isolated modes of operation.
In the areas with considerable solar radiation and wind potential valuable opportunities exist in utilizing these resources. In addition to these renewable resources, the use of controllable resources... 

Design hybrid systems to supply electrical energy for off grid domestic consumer in the remote villages in Iran are the main objective of this work. The hybrid systems considered in this study consist of photovoltaic array, wind turbine, battery and diesel generator. Measured wind speed data used for wind turbine energy production model. The hybrid system optimized to supply 6, 14, 20, 40 and 60 families in Bojnoord, Moorchehkhoort, Kish, Langrood, Khash and Meshkinshahr. The main purpose of optimization is to find the economic system, able to fulfill the energy requirements of a given load distribution; so Iran’s current economy and cost, considered. The optimized results for studied cities... 

This project aims to design a smart microgrid connected to the utility grid in order to supply the demand of Energy Engineering Department at Sharif University of Technology. The electrical structure of this micro-grid is included utility grid, photovoltaic system with energy storage system and a consumer. Due to the energy storage system, an operation strategy is presented that is proportionate to the installed capacities in microgrid and based on a price basis that is determined by the micro-grid operator at the beginning of each day, in order to manage energy is provided. Micro-grid energy management is divided into two sections that the implementation of each part is depended to the... 

Despite the excellent photovoltaic performance of perovskite solar cells (PSCs), the instability of PSCs under severe environment (e.g., humidity, intense light) limits further commercialization of such devices. Therefore, in recent years, many researches are conducted on utilizing Perovskite Quantum Dots (PQDs) to enhance performance of PSCs. Herein, CsPbI3 PQDs interfacial layer is incorporated in the perovskite/hole transport material (HTM) interface, on the purpose of increasing charge carrier mobility and preventing electron-hole recombination to increase performance of the PSCs. CsPbI3 PQDs is synthesized at 170℃ with oleic acid and oleylamine as organic ligands by hot-injection... 

The combination of photovoltaic technology and Organic Rankine Cycle reduces the temperature of the solar panel and, on the other hand, generates separate electricity from excess heat. The reason for the use of the Organic Rankine Cycle is the low temperature of the heat source. It is not economical to use other cycles like steam Rankine cycle in low-temperature heat sources. To maximize the plant factor of the Organic Rankine cycle system, especially when there is not enough solar radiation, it is possible to utilize the flue gas heat recovery in office buildings and reduce the cost of electricity generation. In this project, the simulation of this system is carried out for the Energy... 

In the initial part of this research, 10 selected dams out of 647 existing dams in Iran were selected using ArcGIS software, based on 3 indicators of height above sea level, temperature, horizontal solar radiation and wind speed, and the shadow model was calculated by calculating the radiation angle. The solar radiation on the reservoir water level of one of the selected dams, which is Durood Zan Dam, was checked on 4 days of the year. In the next stage, the design of the floating part of the power plant and its related components, in 3 parts including the main door, the door The pontoon and the main pontoon were done. Platform dimensions were optimized during the design process and to... 

Recently a new topology, namely “common ground inverter” is introduced which since it enjoys a direct connection between AC neutral and DC ground, essentially solves the problem of leakage current in grid connected applications. Moreover, a reduced implementation price and a simple control scheme is associated with this system. The Aforementioned features have absorbed a lot of attention for further research regarding this topology. In this research one of the three introduced topologies is considered in details and its function in supplying local loads and Grid is put to the test. Moreover, important efforts have been taken to improve the properties of the inverter in terms of efficiency,...