Clean Energy Systems and Experiences edited by Kei Eguchi SCIYO Clean Energy Systems and Experiences Edited by Kei Eguchi Published by Sciyo Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2010 Sciyo All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by Sciyo, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Jelena Marusic Technical Editor Martina Peric Cover Designer Martina Sirotic Image Copyright Justin Black, 2010. Used under license from Shutterstock.com First published October 2010 Printed in India A free online edition of this book is available at www.sciyo.com Additional hard copies can be obtained from [email protected] Clean Energy Systems and Experiences, Edited by Kei Eguchi p. cm. ISBN 978-953-307-147-3 free online editions of Sciyo SCIYO.COM Books, Journals and Videos can WHERE KNOWLEDGE IS FREE be found at www.sciyo.com Contents Preface VII Chapter 1 A DC/DC converter for clean-energy applications 1 Nimrod Vázquez, Claudia Hernández and Eslí Vázquez Chapter 2 A dual-input DC-DC converter using clean energy power supplies 19 Kei Eguchi Chapter 3 Development of sustainable energy research and applications 37 Abdeen Mustafa Omer Chapter 4 The application of Ionic liquids in dissolution and separation of lignocellulose 71 Jianji Wang, Yong Zheng and Suojiang Zhang Chapter 5 Decentralized production of hydrogen for residential PEM fuel cells from piped natural gas by low temperature steam- methane reforming using sorption enhanced reaction concept 85 Michael G. Beaver and Shivaji Sircar Chapter 6 Exergy analysis of low and high temperature water gas shift reactor with parabolic concentrating collector 107 Murat OZTURK Chapter 7 Economic analysis of large-scale wind energy conversion systems in central anatolian Turkey 131 Mustafa Serdar GENÇ Chapter 8 Energy systems comparison and clean high tech evolution 155 Gustav R. Grob Chapter 9 Zero emissions future city 165 Jan Gorski and Evgeny Yantovsky Preface Renewable energy sources such as solar power, wind power, hydroelectric power, geothermal power, and so on have attracted much attention as alternatives to fossil fuels, because toxins and pollutants are not produced by these sources. For this reason, these energy sources have come to be known as clean energy. Currently, the introduction of clean energy is inferior to energy conservation in respect of cost. Although clean energy technologies are still under development, they are expected to play a prominent role in the achievement of world energy security and the realization of a sustainable society. Furthermore, clean energy technologies can provide opportunities for reducing greenhouse gases. For this reason, in order to realize a sustainable society through efforts to protect the environment, it is necessary to increase the amount of clean energy as a proportion of total global energy consumption. Therefore, it is a pressing need to develop outstanding clean energy technology. This book reports the latest developments and trends in “clean energy systems and experiences”. Discussions of new theory and novel applications of clean energy systems by a number of innovative researchers have been organized into nine chapters. The information in this book focuses particularly on: (1) Power converters for clean energy applications (Chapters 1 and 2); (2) Renewable energy sources for clean energy applications (Chapters 3 - 5); and (3) Analyses and comparisons of energy systems (Chapters 6 - 9). As a whole, the studies presented here reveal important new directions toward the realization of a sustainable society. The contributors to each chapter are energy scientists and engineers with strong expertise in their respective fields. This book offers a forum for exchanging state of the art scientific information and knowledge. We hope that this work will be used by scientists and engineers working in the area of clean energy and by industry researchers. If any technical errors exist in this book, the authors deeply appreciate readers’ constructive comments for correction and improvement of future editions. Editor Kei Eguchi Department of Technology Education Shizuoka University Japan A DC/DC converter for clean-energy applications 1 A DC/DC converter for clean-energy applications X1 Nimrod Vázquez, Claudia Hernández and Eslí Vázquez A DC/DC converter for clean-energy applications Nimrod Vázquez, Claudia Hernández and Eslí Vázquez Instituto Tecnológico de Celaya México 1. Introduction Fossil fuels are depleting day by day, therefore it is imperative to find out alternative methods in order to fulfill the energy demand of the world. Renewable energy is becoming more important nowadays. There exist applications of renewable energy which employ hundred of MW (high power) and there are also those which uses hundred of W (low power). Applications can also be classified depending if they are connected to the grid or not, as well known as cogeneration and stand alone systems. This last one is a low power application, specially employed in remote places, where electricity is not available. Usually photovoltaic and wind systems are the source of energy in stand alone systems. Efficient use of energy is very important, since there is no utility line; a battery set becomes essential because energy power is provided in an irregular way from the renewable source; leaving aside this issue a power conversion stage is required in order to make sure a good output power quality. The operation of a dc/dc converter applicable in stand alone systems is discussed in this chapter, which is for using clean energy as it could be a photovoltaic panel or a wind turbine. The system optimizes delivered energy in a smart way, but assuring its availability in the best possible way. Chapter is organized as follows: stand alone systems are described first, later on some converters reported in literature are discussed, and finally operation, energy administration and results of a dc/dc converter for clean-energy applications are presented. 2. Stand alone systems and renewable sources Energy is not provided from the utility line for the stand alone systems but from renewable source, which depends on weather conditions. So that, in order to make sure there will exist availability of energy, when load required it, a battery set is traditionally considered. Power consumption is restricted to a maximum limit and it also is a finite measurable quantity, to deliver the more amount of energy its use has to be optimized. A block diagram for stand alone systems is shown in Figure 1. Photovoltaic panel, wind turbine system or both can be used as renewable source of energy; reliable energy is provided by a power converter, which is fed from the renewable source and the battery set, it focus mainly to deliver a regulated voltage to the load. 2 Clean Energy Systems and Experiences Certainly weather conditions restrict the renewable sources, but output power not only 3. State of the art in power conversion for renewable systems depends on wind speed or solar irradiance when it is employed a turbine system or a photovoltaic panel, also depend on the load. System behaviour for constant weather Power converters normally reported in literature (Carrasco et al., 2006) consider not only conditions is shown in Figure 2; traditionally the output power is plotted against its output different power stages, but also different ways of operation. Some of them are connected to voltage, but particularly for this graph the load is been changed, because the system the grid but some others are stand alone systems. Fortunately, two types of converters are depends on it. For different weather conditions similar graph can be obtained but the power typically used no matter configuration: a dc/dc converter and a dc/ac converter. This varies according it. section describes some topologies reported in literature for renewable systems dealing with When a renewable source is connected to a load not necessarily the maximum output power photovoltaic and wind systems. is consumed, as it is shown between A and B points in Figure 2. A maximum power point tracker (MPPT, point B) is employed in order to optimize the obtained energy; however this 3.1 Grid connected systems is not completely required in stand alone application, due to the load is fixed or bounded Grid connected systems deliver the maximum obtainable power to the ac mains from the and the power system requirements could be lower than the maximum obtainable from the photovoltaic (PV) and/or wind system (Carrasco et al., 2006); since the provided energy is renewable source. variable and dependent on weather conditions, the possible released energy is also variable. When considering a photovoltaic system and a specific load connected to the stand alone Algorithms like improved perturbation and observation method (Femia et al., 2009), sliding system, there exist two different possibilities: first one occurs if the maximum energy mode observer technique (Kim et al., 2006), or some others (Park et al., 2006; Kwon et al., obtained from the panel is lower than the output power (point C) then it is necessary to use 2006) are used to track the maximum power point (MPP).