Photovoltaic Modeling Handbook

This book provides the reader with a solid understanding of the fundamental modeling of photovoltaic devices. After the material independent limit of photovoltaic conversion, the readers are introduced to the most well-known theory of "classical" silicon modeling. Based on this, for each of the most important PV materials, their performance under different conditions is modeled. This book also covers different modeling approaches, from very fundamental theoretic investigations to applied numeric simulations based on experimental values. The book concludes wth a chapter on the influence of spectral variations. The information is supported by providing the names of simulation software and basic literature to the field. The information in the book gives the user specific application with a solid background in hand, to judge which materials could be appropriate as well as realistic expectations of the performance the devices could achieve.

Autorentext

Monika Freunek (Müller), studied Mechatronic and Product Engineering at the Universities of Applied Sciences of Bielefeld and Furtwangen, Germany from 2002-2006. After graduation and postdoctoral research at IBM Research Zurich, she worked as a researcher and co-founder of a start-up. Monika Freunek is now at BKW, Switzerland, as an energy specialist. Her main focus in research is modeling of energy and photovoltaic systems under different application conditions. She is an expert in indoor photovoltaics.

Klappentext
The main goal of the book is to give scientists and practioners a comprehensive overview of the state-of-the-art models of all relevant photovoltaic technologies, detail models enabling realistic efficiency calculations, and reliable product design. Photovoltaic Modeling Handbook provides the reader with a solid understanding of the modeling of photovoltaic devices, from very fundamental theoretic investigations to numerical simulations based on ray tracing and experimental values. The book covers both standard applications, models, new approaches and fields of research such as perovskite materials. Recognized subject-matter experts have written the chapters and they refer to simulation software and the basic literature of the field. This groundbreaking book guides the reader to their specific application with solid background information in hand and an assessment of which materials might be appropriate. Specifically, the book covers:

• The physics of photovoltaics and the material independent efficiency limits of photovoltaic devices;
• A detailed model of a silicon-based photovoltaic module and a profound introduction to ray-tracing methods for optical numerical models;
• Numerical modeling methods and results pertaining to amorphous silicon;
• The modeling of organic semiconductors as well as an introduction to kinetic Monte Carlo methods to simulate the dynamics in organic semiconductor devices;
• Reviews a few theories on modeling the device physics of chalcogenide thin-film solar cells such as CdTe and Cu(In,Ga)(Se,S)2 (or CIGS) devices;
• Shows the modeling of stacked multi-material solar cells for ultra-high irradiance applications;
• Details the influence of spectral variations both theoretically and experimentally with a special focus on outdoor applications;
• A discussion on indoor applications and shows the resulting ideal choice of materials and the enhanced indoor efficiencies. Audience The book will be read and used by both academic researchers working on photovoltaic cells and modules, as well as industrial engineers involved in the production and simulation of photovoltaic cells and modules.

Inhalt
Preface xiii

**1 Introduction 1
**Monika Freunek Müller

**2 Fundamental Limits of Solar Energy Conversion 7
**Thorsten Trupke and Peter Würfel

2.1 Introduction 8

2.2 The Carnot Efficiency A Realistic Limit for PV Conversion? 8

2.3 Solar Cell Absorbers Converting Heat into Chemical Energy 10

2.4 No Junction Required The IV Curve of a Uniform Absorber 12

2.5 Limiting Efficiency Calculations 15

2.6 Real Solar Cell Structures 19

2.7 Beyond the Shockley Queisser Limit 20

2.8 Summary and Conclusions 22

Acknowledgement 23

References 24

**3 Optical Modeling of Photovoltaic Modules with Ray Tracing Simulations 27
**Carsten Schinke, Malte R.Vogt and Karsten Bothe

3.1 Introduction 28

3.1.1 Terminology 30

3.2 Basics of Optical Ray Tracing Simulations 32

3.2.1 Ray Optics 32

3.2.1.1 Basic Assumptions 33

3.2.1.2 Absorption of Light 33

3.2.1.3 Refraction of Light at Interfaces 34

3.2.1.4 Modeling of Thin Films 35

3.2.2 Ray Tracing 37

3.2.3 Monte-Carlo Particle Tracing 38

3.2.4 Statistical Uncertainty of Monte-Carlo Results 40

3.2.5 Generating Random Numbers with Non-Uniform Distributions 42

3.3 Modeling Illumination 46

3.3.1 Basic Light Sources 46

3.3.2 Modeling Realistic Illumination Conditions 48

3.3.2.1 Preprocessing of Irradiance Data 49

3.3.2.2 Implementation for Ray Tracing 50

3.3.2.3 Application Example 52

3.4 Specific Issues for Ray Tracing of Photovoltaic Modules 53

3.4.1 Geometries and Symmetries in PV Devices 55

3.4.2 Multi-Domain Approach 57

3.4.2.1 Module domain 59

3.4.2.2 Front Finger Domain 60

3.4.2.3 Front Texture Domain 60

3.4.2.4 Rear Side Domains 61

3.4.3 Post processing of Simulation Results 61

3.4.4 Ray Tracing Application Examples 64

3.4.4.1 Validation of Simulation Results 64

3.4.4.2 Optical Loss Analysis: From Cell to Module 66

3.4.4.3 Bifacial Solar Cells and Modules 68

3.5 From Optics to Power Output 69

3.5.1 Calculation Chain: From Ray Tracing to Module Power Output 70

3.5.1.1 Inclusion of the Irradiation Spectrum 73

3.5.1.2 Calculation of Module Output Power 75

3.5.1.3 Outlook: Energy Yield Calculation 75

3.5.2 Application Examples 76

3.5.2.1 Calculation of Short Circuit Current and Power Output 77

3.5.2.2 Current Loss Analysis: Standard Testing Conditions vs. Field Conditions 79

3.6 Overview of Optical Simulation Tools for PV Devices 80

3.6.1 Analysis of Solar Cells 82

3.6.2 Analysis of PV Modules and Their Surrounding 82

3.6.3 Further Tools Which are not Publicly Available 85

Acknowledgments 85

References 86

**4 Optical Modelling and Simulations of Thin-Film Silicon Solar Cells 93
**Janez Krc, Martin Sever, Benjamin Lipovsek, Andrej Campa and Marko Topic

4.1 Introduction 94

4.2 Approaches of Optical Modelling 95

4.2.1 One-Dimensional Optical Modelling 96

4.2.2 Two- and Three-Dimensional Rigorous Optical Modelling 97

4.2.3 Challenges in Optical Modelling 97

4.3 Selected Methods and Approaches 98

4.3.1 Finite Element Method 98

4.3.2 Coupled Modelling Approach 100

4.4 Examples of Optical Modelling and Simulations 102

4.4.1 Texture Optimization Applying Spatial Fourier Analysis 103

4.4.2 Model of Non-Conformal Layer Growth 110

4.4.3 Optical Simulations of Tandem Thin-Film Silicon Solar Cell 118

4.5 The Role of Illumination Spectrum 129

4.6 Conclusion 133

Acknowledgement 134

References 135

**5 Modelling of Organic Photovoltaics 141
**Ian R. Thompson &lt...