Handbook of Concentrator Photovoltaic Technology

Concentrator Photovoltaics (CPV) is one of the most promising technologies to produce solar electricity at competitive prices. High performing CPV systems with efficiencies well over 30% and multi-megawatt CPV plants are now a reality. As a result of these achievements, the global CPV market is expected to grow dramatically over the next few years reaching cumulative installed capacity of 12.5 GW by 2020. In this context, both new and consolidated players are moving fast to gain a strategic advantage in this emerging market.

Written with clear, brief and self-contained technical explanations, Handbook of Concentrator Photovoltaic Technology provides a complete overview of CPV covering: the fundamentals of solar radiation, solar cells, concentrator optics, modules and trackers; all aspects of characterization and reliability; case studies based on the description of actual systems and plants in the field; environmental impact, market potential and cost analysis.

CPV technology is at a key point of expansion. This timely handbook aims to provide a comprehensive assessment of all CPV scientific, technological and engineering background with a view to equipping engineers and industry professionals with all of the vital information they need to help them sustain the impetus of this encouraging technology.

Key features:

• Uniquely combines an explanation of the fundamentals of CPV systems and components with an overview of the market place and their real-life applications.

• Each chapter is written by well-known industry specialists with extensive expertise in each particular field of CPV technology.

• Reviews the basic concepts of multi-junction solar cells and new concepts for CPV cells, highlighting the key differences between them.

• Demonstrates the state of the art of several CPV centres and companies.

• Facilitates future cost calculation models for CPV.

• Features extensive case studies in each chapter, including coverage of CPV modules and systems.

Autorentext

Carlos Algora received his B.Sc. degree in Physics in 1986 and his PhD in Physics in 1990, both from the Universidad Complutense de Madrid. He joined the Solar Energy Institute of the Technical University of Madrid in 1985 where he became Associate Professor in 1991 and a Full Professor in 2008. Since 1996 he has been the head of the III-V Semiconductors Group, which is devoted to the modelling, technology, characterization and reliability of III-V solar cells. Together with his team he has helped to develop several World efficiency record concentrator cells. He has been the main researcher of more than 40 R&D projects, has published more 230 scientific papers and has authored several book chapters.

Ignacio Rey-Stolle is an Associate Professor at the Solar Energy Institute of the Technical University of Madrid, where he obtained his PhD in 2001. During his scientific career he has accumulated more than 17 years working in the field of high efficiency concentrator solar cells, during which he has contributed to several efficiency records. His research activities encompass the whole life cycle of concentrator solar cells, including design and simulation, epitaxial growth, fabrication, characterization and reliability studies. Ignacio Rey-Stolle has co-authored more than 100 scientific papers, three book chapters and one patent.

Inhalt

List of Contributors xix

Preface xxiii

1 Direct Normal Radiation 1
Daryl R. Myers

1.1 Concepts and Definitions 1

1.1.1 Orbital and Geometrical Considerations 1

1.1.2 The Solar Constant 2

1.1.3 Temporal Variations in Extraterrestrial Radiation (ETR) 3

1.1.4 Extraterrestrial Radiation Spectral Power Distribution 4

1.1.5 The Atmospheric Filter 6

1.2 Measuring Broadband Direct Solar Radiation 8

1.2.1 Pyrheliometers 8

1.2.2 Rotating Shadow Band Radiometers 11

1.2.3 Reference Standards, the World Radiometric Reference (WRR) 13

1.2.4 Calibration of Pyrheliometers 16

1.2.5 Accuracy and Uncertainty 17

1.2.6 Summary of Guide to Uncertainty in Measurement (GUM) Approach 18

1.2.7 Measurement Data Quality 20

1.3 Modeling Broadband Direct Solar Radiation 21

1.3.1 Models for Direct Beam Irradiance 21

1.3.2 Atmospheric Component Transmittance 22

1.3.3 Estimating Direct Beam Radiation from Hemispherical Data 25

1.4 Modeling Spectral Distributions 26

1.4.1 Bird Simple Spectral Model (SPCTRL2) 27

1.4.2 Simple Model for Atmospheric Transmission of Sunshine (SMARTS) 28

1.4.3 Spectral Distributions from Broadband Data 28

1.5 Resources for Broadband Estimates of CPV Performance 29

1.5.1 Broadband Direct Beam Radiation Data Resources 29

1.5.2 Typical Meteorological Year Data for CPV Performance Estimates 31

1.5.3 CPV Spectral Performance Issues 33

1.6 Sunshape 33

1.6.1 The Solar Disk 33

1.6.2 Circumsolar Radiation 36

1.6.3 Recent Circumsolar Radiation Research 39

1.7 Direct Solar Radiation Climates 40

1.7.1 Measurement Networks and Data 41

1.7.2 Concentrating Solar Power Site Selection 41

1.7.3 Concentrating Solar Power Resource Map Examples 43

1.7.4 Solar Resource Maps and Data Internet Resources 47

1.8 Consensus Standards for Direct Solar Radiation Applications 48

1.8.1 World Radiometric Reference 48

1.8.2 Solar Radiometric Instrumentation Calibration 48

1.8.3 Spectral Calibration Standards 49

1.8.4 Standard and Reference Spectral Distributions 49

Glossary 50

List of Acronyms 50

List of Symbols 51

References 53

2 Concentrator Multijunction Solar Cells 59
Ignacio Rey-Stolle, Jerry M. Olson, and Carlos Algora

2.1 Introduction 59

2.2 Fundamentals 60

2.2.1 Fundamentals of Photovoltaic Cells 60

2.2.2 Fundamentals of Multijunction Solar Cells 63

2.3 Multijunction Solar Cell Structures 67

2.3.1 Historical Development of Multijunction PV Converters 68

2.3.2 Designing Multijunction Solar Cell Structures 73

2.4 Multijunction Solar Cell Modeling 79

2.4.1 Numerical Modeling of Multijunction Solar Cell Structures 79

2.4.2 Analytical Modeling of Multijunction Solar Cells 81

2.4.3 Further Steps: Distributed Circuit-based Modeling 98

2.5 Concentrator Requirements 103

2.5.1 High Efficiency 103

2.5.2 Series Resistance. Grid Designs 107

2.5.3 Tunnel Junctions 110

2.5.4 Distributed Effects 113

2.5.5 Atmospheric Spectral Variations and Impact on Energy Yield 116

2.5.6 Temperature Effects 118

2.6 Description of Different Cell Approaches 118

2.6.1 Lattice-matched GaInP/GaAs/Ge 118

2.6.2 Metamorphic GaInP/GaInAs/Ge 119

2.6.3 Inverted Metamorphic GaInP/GaAs/GaInAs 120

2.6.4 Double Sided Epi 122

2.6.5 Lattice Matched GaInP/GaAs/GaInNAs 122

2.6.6 Quantum Dot and Quantum Well Multijunction Solar Cells 123

2.6.7 More Junctions (4, 5, 6) 123

2.6.8 Stacked Multijunction Cells 124

2.6.9 III-Vs on Silicon 124

2.6.10 Epitaxial Liftoff 126

Acknowledgements 127

Glossary 127 List of Ac...