Photovoltaics

A comprehensive tutorial on photovoltaic technology now fully updated to include solar storage and the latest methods for on-site plant measurements

Starting with the basic principles of solar energy, this fully updated, practical text explains the fundamentals of semiconductor physics and the structure and functioning of the solar cell. It describes the latest measurement techniques for solar modules, and the planning and operation of grid-connected and off-grid PV systems.

It also looks at other thin film cells, hybrid wafer cells, and concentrator systems. Additionally, this Second Edition covers solar modules and solar generators; system technology of grid connected plants; the storage of solar energy; photovoltaic measurement technology; the planning and operation of grid-connected systems; economic efficiency of PV systems; and the future development of PV.

• Presents the latest advances in PV R&D and industry deployment

• Updated illustrations and tabular data reflect current state-of-the-art and PV technology efficiencies

• Offers expanded tutorial sections to aid teaching and self-study

• Includes a brand-new chapter on Solar Energy Storage

• Features two enlarged chapters--one on up-to-date photovoltaic metrology and the other on the future developments in photovoltaics

• Comes along with the accompanying website www.textbook-pv.org which offers free downloadable figures of the book, solutions of exercises, additional free PV software etc.

Developed to prepare engineering students for the PV industry, this practical text is an essential PV primer.

Autorentext

Konrad Mertens, PhD, is Professor at Münster University of Applied Sciences, Germany, where he covers the subjects of photovoltaics, sensor technology, and optoelectronics. He is also the founder and head of the university's photovoltaic test lab and head of the lab of sensor technology and optoelectronics.

Inhalt
Preface to the First International Edition xv

Preface to the Second International Edition xvii

Abbreviations xix

1 Introduction 1

1.1 Introduction 1

1.1.1 Why Photovoltaics? 1

1.1.2 Who Should Read This Book? 2

1.1.3 Structure of the Book 2

1.2 What Is Energy? 3

1.2.1 Denition of Energy 3

1.2.2 Units of Energy 4

1.2.3 Primary, Secondary, and End Energy 5

1.2.4 Energy Content of Various Substances 6

1.3 Problems with Today's Energy Supply 7

1.3.1 Growing Energy Requirements 7

1.3.2 Tightening of Resources 8

1.3.3 Climate Change 9

1.3.4 Hazards and Disposal 11

1.4 Renewable Energies 11

1.4.1 The Family of Renewable Energies 11

1.4.2 Advantages and Disadvantages of Renewable Energies 12

1.4.3 Previous Development of Renewable Energies 13

1.5 Photovoltaics The Most Important in Brief 13

1.5.1 What Does Photovoltaics Mean? 13

1.5.2 What Are Solar Cells and Solar Modules? 14

1.5.3 How Is a Typical Photovoltaic Plant Structured? 14

1.5.4 What Does a Photovoltaic Plant Bring? 15

1.6 History of Photovoltaics 16

1.6.1 How It all Began 16

1.6.2 The First Real Solar Cells 17

1.6.3 From Space to Earth 19

1.6.4 From Toy to Energy Source 20

2 Solar Radiation 23

2.1 Properties of Solar Radiation 23

2.1.1 Solar Constant 23

2.1.2 Spectrum of the Sun 23

2.1.3 Air Mass 25

2.2 Global Radiation 25

2.2.1 Origin of Global Radiation 25

2.2.2 Contributions of Diuse and Direct Radiation 26

2.2.3 Global Radiation Maps 28

2.3 Calculation of the Position of the Sun 30

2.3.1 Declination of the Sun 30

2.3.2 Calculating the Path of the Sun 32

2.4 Radiation on Tilted Surfaces 35

2.4.1 Radiation Calculation with the Three-component Model 35

2.4.1.1 Direct Radiation 35

2.4.1.2 Diuse Radiation 36

2.4.1.3 Reected Radiation 37

2.4.2 Radiation Estimates with Diagrams and Tables 38

2.4.3 Yield Gain through Tracking 41

2.5 Radiation Availability and World Energy Consumption 41

2.5.1 The Solar Radiation Energy Cube 41

2.5.2 The Sahara Miracle 45

3 Fundamentals of Semiconductor Physics 47

3.1 Structure of a Semiconductor 47

3.1.1 Bohr's Atomic Model 47

3.1.2 Periodic Table of Elements 49

3.1.3 Structure of the Silicon Crystal 49

3.1.4 Compound Semiconductors 49

3.2 Band Model of a Semiconductor 51

3.2.1 Origin of Energy Bands 51

3.2.2 Dierences in Isolators, Semiconductors, and Conductors 53

3.2.3 Intrinsic Carrier Concentration 53

3.3 Charge Transport in Semiconductors 55

3.3.1 Field Currents 55

3.3.2 Diusion Currents 56

3.4 Doping of Semiconductors 57

3.4.1 n-Doping 57

3.4.2 p-Doping 58

3.5 The pn Junction 59

3.5.1 Principle of Method of Operation 59

3.5.2 Band Diagram of the pn Junction 61

3.5.3 Behavior with Applied Voltage 62

3.5.4 Diode Characteristics 63

3.6 Interaction of Light and Semiconductors 64

3.6.1 Phenomenon of Light Absorption 64

3.6.1.1 Absorption Coecient 65

3.6.1.2 Direct and Indirect Semiconductors 65

3.6.2 Light Reection on Surfaces 67

3.6.2.1 Reection Factor 67

3.6.2.2 Antireection Coating 69

4 Structure and Method of Operation of Solar Cells 71

4.1 Consideration of the Photodiode 71

4.1.1 Structure and Characteristics 71

4.1.2 Equivalent Circuit 73

4.2 Method of Function of the Solar Cell 73

4.2.1 Principle of the Structure 73

4.2.2 Recombination and Diusion Length 74 <...