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.

Contributors List

Foreword

An Introduction to Concentrator Photovoltaics
I. Rey–Stolle and C. Algora

Chapter 1 Direct Normal Radiation
D. R. Myers

1.1 Concepts and Definitions 1

1.2 Measuring Broadband Direct Solar Radiation 7

1.3 Modeling Broadband Direct Solar Radiation 21

1.4 Modeling Spectral Distributions 26

1.5 Resources for Broadband Estimates of CPV Performance 29

1.6 Sunshape 33

1.7 Direct Solar Radiation Climates 40

1.8 Consensus Standards for Direct Solar Radiation Applications 47

Glossary 49

List of acronyms 49

List of symbols 50

References 53

Chapter 2 Concentrator Multijunction Solar Cells
I. Rey–Stolle, J. M. Olson, C. Algora

2.1 Introduction 59

2.2 Fundamentals 60

2.3 Multijunction solar cell structures 67

2.4 Multijunction solar cell modeling 79

2.5 Concentrator requirements 103

2.6 Description of different cell approaches 119

Acknowledgements 128

Glossary 128

List of acronyms 128

List of symbols 129

References 131

Chapter 3 Emerging High Efficiency Concepts for Concentrator Solar Cells
I. Tobías and A. Luque

3.1 Introduction 139

3.2 Thermodynamic efficiency limits 140

3.3 Detailed balance modeling of solar cells 144

3.4 Solar cell concepts exceeding the single junction Shockley–Queisser limit 149

3.5 Other concepts 162

3.6 Nanostructures in solar cells 165

Glossary 182

List of acronyms 182

References 183

Chapter 4 CPV Optics
R. Mohedano and R. Leutz

4.1 Introduction 189

4.2 Light, optics and concentration 190

4.3 Optical background 194

4.4 Design of the optical train: Calculation of surfaces 204

4.5 Performance analysis and optimization of the optical train 215

4.6 Optics Manufacturing 227

4.7 Impact of CPV Optics in a nutshell 235

Glossary 237

List of acronyms 237

List of symbols 238

Annex 4–I: Étendue calculation 243

Annex 4–II: 2D treatment of rotational and linear 3D optical systems 245

Annex 4–III: Design of the XR concentrator 247

Chapter 5 Temperature Effects on CPV Solar Cells, Optics and Modules
I. García, M. Victoria, I. Antón

5.1 Introduction 249

5.2 Effects of Temperature on CPV Solar cells 249

5.3 Temperature effects and thermal management in CPV optics and modules 270

Glossary 291

List of acronyms 291

List of symbols 291

References 293

Chapter 6 CPV Tracking and Trackers
I. Luque–Heredia, P. Magalhães, M.Muller

6.1 Introduction 297

6.2 Requirements and specifications 298

6.3 Basic taxonomy of CPV trackers 302

6.4 Design of CPV trackers structural considerations 304

6.5 Sun Tracking Control 311

6.6 Sun tracking accuracy 319

6.7 Designing for optimal manufacturing and field works 326

6.8 Description and performance of current tracker approaches 331

6.9 International standards for solar trackers 339

References 342

Chapter 7 CPV Modules
S. Askins and G. Sala

7.1 Introduction 345

7.2 What is a CPV module? 345

7.3 Definition, functions, and structure of a CPV module 347

7.4 Design process and prototyping stages 352

7.5 Concentration ratio and cell size 359

7.6 Opto–mechanics of CPV modules 366

7.7 Electrical design 379

7.8 Thermal Design 383

7.9 Venting Considerations 397

7.10 Manufacturing processes for CPV modules 398

7.11 Standards applicable to CPV modules 407

Glossary 409

References 411

Annex 7–I: Abengoa s CPV Modules and Systems 413

Annex 7–II: CPV Modules and Systems from Daido Steel 421

Annex 7–III: Soitec CPV Modules and Systems 427

Annex 7–IV: Suncore Photovoltaics Modules 435

Chapter 8 CPV Power Plants
M. Martínez, D. Sánchez, F. Rubio, E. F. Fernández, F. Almonacid, N. Abela, T. Zech,

T. Gerstmaier

8.1 Introduction 443

8.2 Construction of CPV plants 444

8.3 CPV inverters: configurations and sizing 456

8.4 Optimized distribution of trackers 460

8.5 Considerations on environmental impact and dual use of the land 468

8.6 CPV plant monitoring and production data analysis 469

8.7 Operation and Maintenance 475

8.8 Power rating of a CPV plant 481

8.9 Modeling the energy production of CPV power plants 488

Glossary 496

List of acronyms 496

List of symbols 497

References 499

Annex 8–I: Software Tools for CPV Plant Design and Analysis 503

Annex 8–II: CPV power plants at ISFOC 513

Annex 8–III: Soitec Power Plants 525

Chapter 9 Reliability
C. Algora, P. Espinet, M. Vázquez, N. Bosco, D. Miller, S. Kurtz, F. Rubio, R. McConnell

9.1 Introduction 533

9.2 Fundamentals of reliability 533

9.3 Reliability of solar cells 546

9.4 Reliability of modules 562

9.5 Reliability of systems and plants 576

9.6 Standards Development for CPV 592

Acknowledgement 598

References 599

Chapter 10 CPV Multijunction Solar Cell Characterization
C. R. Osterwald and G. Siefer

10.1 Introduction 605

10.2 Basic concepts about multijunction solar cells for characterization purposes 606

10.3 Spectral matching and adjustment 610

10.4 Flash solar simulators: description and limitations 616

10.5 Concentrator solar cell characterization 619

Acknowledgments 628

Glossary 629

List of acronyms 629

List of symbols 629

References 631

Chapter 11 Characterization of Optics for Concentrator Photovoltaics
M. Hernández

11.1 Introduction 633

11.2 Geometrical characterization 634

11.3 Optical characterization 642

Glossary 655

List of acronyms 655

List of symbols 655

References 656

Chapter 12 Characterization of CPV Modules and Receivers
C. Domínguez, R. Herrero, I. Antón

12.1 Introduction 657

12.2 Figures of merit of PV Concentrators 658

12.3 Instruments and methods for CPV characterization 661

12.4 Indoor measurements of CPV modules 682

Glossary 698

List of acronyms 698

List of symbols 698

References 700

Chapter 13 Life Cycle Analysis of CPV Systems
V. Fthenakis

13.1 Introduction 705

13.2 Case study description 706

13.3 Methodology 707

13.4 Life–cycle Inventory Analysis 708

13.5 System Performance Data and Estimates 715

13.6 Energy Payback Time 716

13.7 Greenhouse and Toxic Gas Emissions 716

13.8 Land and Water use in CPV Systems 719

13.9 Discussion and Comparison with other CPV and PV systems 721

Glossary 724

List of acronyms 724

List of symbols 724

References 725

Annex 13–I: Energy Flow Diagrams for Amonix 7700 system components 727

Chapter 14 Cost Analysis and Market Deployment
C. Algora, D. L. Talavera, G. Nofuentes, I. Luque–Heredia

14.1 Introduction 733

14.2 Basic concepts of cost and profitability analysis 734

14.3 Review of profitability analysis 737

14.4 The cost of CPV 750

14.5 CPV Market Deployment 777

Glossary 778

References 780

Index

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.