Photovoltaics E-Book

Heinrich Häberlin

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 1229

Veröffentlichungsjahr: 2012

Beschreibung

With the explosive growth in PV (photovoltaic) installations globally, the sector continues to benefit from important improvements in manufacturing technology and the increasing efficiency of solar cells, this timely handbook brings together all the latest design, layout and construction methods for entire PV plants in a single volume.

Coverage includes procedures for the design of both stand-alone and grid-connected systems as well as practical guidance on typical operational scenarios and problems encountered for optimum PV plant performance.

This comprehensive resource will benefit electrical engineer and other electrical professionals in PV systems, especially designers and installers of PV plants or the product manufacturing and testing supply chain. Advanced students on renewable energy courses will find this useful background reading and it will be an invaluable desk reference for PV plant builders and owners.

Leseprobe

Contents

Cover

Title Page

Copyright

Dedication

Foreword

Preface

About the Author

Acknowledgements

Note on the Examples and Costs

List of Symbols

Chapter 1: Introduction

1.1 Photovoltaics – What's It All About?

1.2 Overview of this Book

1.3 A Brief Glossary of Key PV Terms

1.4 Recommended Guide Values for Estimating PV System Potential

1.5 Examples

1.6 Bibliography

Chapter 2: Key Properties of Solar Radiation

2.1 Sun and Earth

2.2 Extraterrestrial Radiation

2.3 Radiation on the Horizontal Plane of the Earth's Surface

2.4 Simple Method for Calculating Solar Radiation on Inclined Surfaces

2.5 Radiation Calculation on Inclined Planes with Three-Component Model

2.6 Approximate Annual Energy Yield for Grid-Connected PV Systems

2.7 Composition of Solar Radiation

2.8 Solar Radiation Measurement

2.9 Bibliography

Chapter 3: Solar Cells: Their Design Engineering and Operating Principles

3.1 The Internal Photoelectric Effect in Semiconductors

3.2 A Brief Account of Semiconductor Theory

3.3 The Solar Cell: A Specialized Semiconductor Diode with a Large Barrier Layer that is Exposed to Light

3.4 Solar Cell Efficiency

3.5 The Most Important Types of Solar Cells and the Attendant Manufacturing Methods

3.6 Bifacial Solar Cells

3.7 Examples

3.8 Bibliography

Chapter 4: Solar Modules and Solar Generators

4.1 Solar Modules

4.2 Potential Solar Cell Wiring Problems

4.3 Interconnection of Solar Modules and Solar Generators

4.4 Solar Generator Power Loss Resulting from Partial Shading and Mismatch Loss

4.5 Solar Generator Structure

4.6 Examples

4.7 Bibliography

Chapter 5: PV Energy Systems

5.1 Stand-alone PV Systems

5.2 Grid-Connected Systems

5.3 Bibliography

Chapter 6: Protecting PV Installations Against Lightning

6.1 Probability of Direct Lightning Strikes

6.2 Lightning Strikes: Guide Values; Main Effects

6.3 Basic Principles of Lightning Protection

6.4 Shunting Lightning Current to a Series of Down-conductors

6.5 Potential Increases; Equipotential Bonding

6.6 Lightning-Current-Induced Voltages and Current

6.7 PV Installation Lightning Protection Experiments

6.8 Optimal Sizing of PV Installation Lightning Protection Devices

6.9 Recommendations for PV Installation Lightning Protection

6.10 Recap and Conclusions

6.11 Bibliography

Chapter 7: Normalized Representation of Energy and Power of PV Systems

7.1 Introduction

7.2 Normalized Yields, Losses and Performance Ratio

7.3 Normalized Diagrams for Yields and Losses

7.4 Normalized PV Installation Power Output

7.5 Anomaly Detection Using Various Types of Diagrams

7.6 Recap and Conclusions

7.7 Bibliography

Chapter 8: PV Installation Sizing

8.1 Principal of and Baseline Values for Yield Calculations

8.2 Energy Yield Calculation for Grid-Connected Systems

8.3 Sizing PV Installations that Integrate a Battery Bank

8.4 Insolation Calculation Freeware

8.5 Simulation Software

8.6 Bibliography

Chapter 9: The Economics of Solar Power

9.1 How Much Does Solar Energy Cost?

9.2 Grey Energy; Energy Payback Time; Yield Factor

9.3 Bibliography

Chapter 10: Performance Characteristics of Selected PV Installations

10.1 Energy Yield Data and Other Aspects of Selected PV Installations

10.2 Long-Term Comparison of Four Swiss PV Installations

10.3 Long-Term Energy Yield of the Burgdorf Installation

10.4 Mean PV Installation Energy Yield in Germany

10.5 Bibliography

Chapter 11: In Conclusion . . .

Appendix A: Calculation Tables and Insolation Data

A1 Insolation Calculation Tables (see Chapter 2)

A2 Aggregate Monthly Horizontal Global Insolation

A3 Global Insolation for Various Reference Locations

A4 RB Factors for Insolation Calculations Using the Three-Component Model

A5 Shading Diagrams for Various Latitudes

A6 Energy Yield Calculation Tables

A7 kT and kG Figures for Energy Yield Calculations

A8 Insolation and Energy Yield Calculation Maps

Appendix B: Links; Books; Acronyms; etc.

B1 Links to PV Web Sites

B2 Books on Photovoltaics and Related Areas

B3 Acronyms

B4 Prefixes for Decimal Fractions and Metric Multiples

B5 Conversion Factors

B6 Key Physical Constants

Index

This edition first published 2012 © 2012, John Wiley & Sons, Ltd

Registered office John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom

Authorised Translation from the German language second edition published by Electrosuisse (2010)

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Neither the author nor the publisher are responsible or liable for any error and/or incomplete information in this book, or for any loss, damage or injury that could potentially result from using the information and advice contained in this book. The various electrical configurations and processes discussed in this book are presented without regard for the patent status of any such element; are presented for educational purposes only and may only be used with the express permission of the relevant patent or licence holder, if any.

Library of Congress Cataloguing-in-Publication Data

Häberlin, Heinrich.

Photovoltaics: system design and practice / Heinrich Häberlin; translated by Herbert Eppel.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-119-99285-1 (cloth)

1. Photovoltaic power systems–Design and construction. 2. Photovoltaic power systems–Standards. 3. Photovoltaic power generation. I. Title.

TK1087.H33 2012

621.31′244–dc23

2011032983

A catalogue record for this book is available from the British Library.

Print ISBN: 9781119992851

To my wife Ruth and my children Andreas and Kathrin, who, while I was writing this book, weren't able to spend as much time with me as they would have liked – and to all those who want to see our society transition to sustainable and responsible electricity generation.

Foreword

Energy and the concerns it raises for individuals, society at large and the environment, is a more burning issue today than ever before. Evolutions such as climate change, energy security issues, energy market deregulation, energy price fluctuations and the like have made energy the centre of a multi-faceted debate where the need for sustainable energy and improved energy efficiency are taking centre stage as never before. The European Commission's objectives for 2020 in this regard are both courageous and pioneering.

The Stern Report issued by the British government in 2006 noted that global warming and its worldwide economic repercussions constitute the widest-ranging failure of free market mechanisms that the world has ever seen. This report also quantified the economic costs of this evolution. The “business as usual” attitude that unfortunately still prevails in the business and political communities is going to cost us dearly; and the longer we wait to act, the higher the cost will be. A growing number of politicians, business leaders, and consumers have come to the realization that action must be taken, and that such action will not come cheap.

The timing of this book's publication could not be better. Admittedly photovoltaics is no magic bullet solution for the myriad problems we face but photovoltaics is one of the key technologies that will bring us closest to a sustainable energy supply in the foreseeable and distant future. Many technical and other obstacles remain to be surmounted before photovoltaics can do this, however, the undeniable fact of the matter is that photovoltaics is now the subject of feverish and rapid worldwide development on an industrial scale. The annual growth rates of upwards of 40 percent registered by the photovoltaics industry are all the more remarkable in light of the recent financial crisis, not to mention past economic recessions.

The term photovoltaics is often associated primarily with solar cells and solar modules. As these are the core elements of photovoltaic technology, this mindset makes perfect sense. However, it does not go far enough when it comes to characterizing the energy production of a solar power installation. Only if we regard photovoltaics as an energy system can we begin to make accurate statements concerning its contribution to the energy supply. Moreover, regarding a phenomenon as a system often allows us to connect the dots between theory and practice, paradigm and experience.

As growing numbers of PV installations are put into operation, questions are increasingly being raised concerning their quality and reliability. Only a PV installation that works properly can genuinely contribute to the energy supply. Hence such issues are looming ever larger worldwide. One of the great virtues of the present book is that it places tremendous emphasis on the system related aspects of photovoltaics.

Over the course of his many years of research on the system related aspects of photovoltaics, Prof. Hberlin has accumulated unparalleled experience that is richly detailed in his numerous publications on the subject. He has now made this experience available to a wider public, via this book, which in using its author's experience as a springboard, provides a wealth of insights and highly practical information concerning the design and operation of PV installations. In so doing, this book also addresses an increasingly pressing problem, namely that rapid growth in the photovoltaics industry and other renewable energy sectors will increase the need for qualified individuals in this domain. Thus education and training are a matter of growing importance in this regard.

I would like to on one hand express my gratitude to Prof. Hberlin for having written this book, and on the other congratulate him on his willingness to share his photovoltaics expertise with a wider audience via this book, which I feel will make a significant contribution to the advancement of photovoltaic technology. I am confident that this richly detailed and very complete book will enable numerous photovoltaics engineers, researchers and other professionals to gain greater insight into photovoltaics, and particularly into the practical aspects of this intriguing field.

Stefan Nowak, Ph.D.Chairman of the International Energy Agency Photovoltaics Power SystemsProgramme (IEA PVPS)St. Ursen, Switzerland

Preface

The PV industry has experienced an exponential growth since the appearance of the first edition of this book in German in 2007 and ever-larger PV installations are being realized in an ever-growing number of countries. The tremendous interest shown in the first edition of this book, as well as the extensive positive feedback it elicited, show that photovoltaics, which is discussed comprehensively and in all its complexity in this book, is a topic of tremendous importance nowadays.

Therefore the second edition published also in German in 2010 goes into even greater depth on a number of matters and also explores some aspects of and insights into photovoltaics that were not contained in the first edition. For this second edition, I have extensively revised, updated and expanded the material from the first edition in such a way that, using the information in this book, designers can make very close sizing and yield estimates for PV installations at any site worldwide between 40 °S and 60 °N. In addition to updating my own extremely extensive PV installation monitoring data, I have also included energy yield figures from other countries, thanks to the generosity of the relevant operators who kindly provided data concerning their installations.

Considering the success of the two German books and the expressed interest also from many English speaking PV engineers, it was decided to translate this book into English to make my extended PV experience available also to them. The present book is an exact translation into English of the extended second German edition published in 2010.

Since the finalisation of the German book and the translation, prices for PV modules have considerably dropped further especially in 2011. For large quantities of crystalline modules prices of 1 per Wp or even somewhat less were offered in autumn 2011, i.e. even less than the lowest values indicated in the book. Therefore the price of PV electricity is now already very close to competiveness with conventional electricity in many countries.

Heinrich HäberlinErsigenOctober 2011

About the Author

After earning a Masters degree in electrical engineering from ETH Zurich, Heinrich Häberlin became a staff researcher at the ETH Microwave Lab. During this time he developed hardware, software and numerous learning applications for a computerized teaching and learning system that was used at ETH until 1988. He earned a doctorate in 1978, based on the thesis he wrote concerning this system.

From 1979 to 1980, Dr. Häberlin headed a team at the Zellweger Company that worked on the development of hardware and software for microprocessor-based control of a complex short-wave radio system. In late1980 he was appointed a professor to the engineering school in Burgdorf, Switzerland, where from 1980 to 1988 besides electrical engineering he also taught computer science.

Prof. Häberlin has been actively involved in photovoltaics since 1987. In 1988 he established the Bern University of Applied Sciences Photovoltaics Lab, where he and his staff mainly investigate the behaviour of grid-connected systems. Since 1989 he has also been operating his own PV installation. In 1988 he began testing various PV inverters and in 1990 he initiated a series of lab experiments concerning PV installation lightning protection. Prof. Häberlin's PV Lab has, since 1992, also been continuously monitoring more than 70 PV installations, mainly under the auspices of research projects commissioned by Switzerland's Federal Office for Energy. His lab also carries out specialized measurements of PV installation components for the relevant manufacturers and also works on various EU projects.

Prof. Häberlin has been teaching photovoltaics at Bern University of Applied Sciences since 1989. He is a member of Electrosuisse, ETG, the Swiss TK82 panel of experts on PV installations, and the IEC's International Photovoltaics Standards Committee TC82.

Acknowledgements

I would like to thank all of the private and public sector organizations that kindly provided photos, graphics, data and other documentation for this book. Without these elements, I would not have been able to provide such a detailed and in-depth account of the relevant issues.

I would also like to express my heartfelt gratitude to my past and current assistants, who carried out investigations and analyses in connection with numerous research projects and whose work products I have used in this book. I also owe a debt of gratitude to the following organizations that commissioned and financed the aforementioned research projects: the Swiss Ministry of Energy; the Swiss Ministry of Science and Education; the Bern Canton Office of Water and Energy Resource Management; and various power companies (namely, Localnet, Bernische Kraftwerke, Gesellschaft Mont Soleil, Elektra Baselland and Elektrizitätswerk der Stadt Bern).

My former assistants Christoph Geissbühler, Martin Kämpfer and Urs Zwahlen, and my current assistants Luciano Borgna and Daniel Gfeller, read the manuscript for the first edition of this book in German and pointed out errors and elements that were unclear. My colleagues Dr Urs Brugger and Michael Höckel read certain sections of the first-edition manuscript and provided helpful suggestions.

The manuscript for the second book in German was read by my current assistants Daniel Gfeller, David Joss, Monika Münger and Philipp Schärf, who likewise pointed out errors and elements that were unclear.

I would like to express my gratitude to all of these individuals for their assistance.

Heinrich HäberlinErsigenJanuary 2010

Note on the Examples and Costs

Many of the chapters in this book contain examples whose numbers were in many cases calculated using spreadsheet programs that round off the exact numbers that were originally input. On the other hand, for reasons of space many of the numbers in the tables in Appendix A have been rounded off to two decimal places. Hence, when used for actual calculations, these rounded-off numbers may under certain circumstances differ slightly from the counterpart numbers indicated in the examples.

In several sections of this book, costs of PV modules or PV systems or feed-in tariffs are given in euros. In some cases or examples, especially where the situation in Switzerland is discussed, costs in Swiss francs (SFr) are expressed as their equivalent in euros (). The exchange rate used in this case was the exchange rate during the finalization of the German book, i.e. 1 Swiss franc is equivalent to about 0.67 euros. Due to the problems on the financial markets, there were extreme variations of this exchange rate in 2010 and 2011 (variation between about 1 SFr 0.67 and 1 SFr 1 ). For actual values in Swiss francs the actual exchange rate has to be used.