Photovoltaics

Professor Heinrich Häberlin, Engineering and Information Technology, Berne University of Applied Sciences, SwitzerlandProfessor Häberlin is the head of the photovoltaics laboratory at the Berne University of Applied Sciences (BFH). He obtained his academic degrees from the Swiss Institute of Technology (ETH) in Zurich, where he also worked several years as an assistant and assistant-in chief. After some years in the industry he took up his present appointment at BFH. He has been active in education and research in photovoltaic systems technology for about 20 years, has authored more than 125 scientific publications and is a member of Electrosuisse and IEC TC82, the international commission for PV standards.Translated by Herbert Eppel at HE Translations, Leicester, UK (https://HETranslations.uk) DISCLAIMER: By including the link to this site, this does not mean the site is endorsed by Wiley

• Foreword xiiiPreface xvAbout the Author xviiAcknowledgements xixNote on the Examples and Costs xxiList of Symbols xxiii1 Introduction 11.1 Photovoltaics – What’s It All About? 11.2 Overview of this Book 101.3 A Brief Glossary of Key PV Terms 111.3.1 Relevant Terminology Relating to Meteorology, Astronomy and Geometry 111.3.2 PV Terminology 131.4 Recommended Guide Values for Estimating PV System Potential 141.4.1 Solar Cell Efficiency ηPV 141.4.2 Solar module Efficiency ηm 141.4.3 Energy Efficiency (Utilization Ratio, System Efficiency) ηE 151.4.4 Annual Energy Yield per Installed Kilowatt of Peak Installed Solar Generator Capacity 151.4.5 PV Installation Space Requirements 171.4.6 Cost per Installed Kilowatt of Peak Power 171.4.7 Feed-in Tariffs; Subsidies 181.4.8 Worldwide Solar Cell Production 201.4.9 Installed Peak Capacity 211.4.10 The Outlook for Solar Cell Production 221.5 Examples 241.6 Bibliography 252 Key Properties of Solar Radiation 272.1 Sun and Earth 272.1.1 Solar Declination 272.1.2 The Apparent Path of the Sun 282.2 Extraterrestrial Radiation 312.3 Radiation on the Horizontal Plane of the Earth’s Surface 322.3.1 Irradiated Energy H on the Horizontal Plane of the Earth’s Surface 342.4 Simple Method for Calculating Solar Radiation on Inclined Surfaces 392.4.1 Annual Global Irradiation Factors 442.4.2 Elementary Radiation Calculation Examples for Inclined Surfaces 472.5 Radiation Calculation on Inclined Planes with Three-Component Model 492.5.1 Components of Global Radiation on the Horizontal Plane 492.5.2 Radiation Reflected off the Ground 502.5.3 The Three Components of Radiation on Inclined Surfaces 512.5.4 Approximate Allowance for Shading by the Horizon 542.5.5 Effect of Horizon and Façade/Roof Edge Elevation on Diffuse Radiation (Sky and Reflected Radiation) 582.5.6 Total Energy Incident on Inclined Surfaces (Generic Case) 622.5.7 Retrospective Calculation of Irradiance Incident on Inclined Solar Generators, Using Global Radiation Readings on the Horizontal Plane 632.5.8 Examples of Radiation Calculations with the Three-Component Method 642.6 Approximate Annual Energy Yield for Grid-Connected PV Systems 682.6.1 Examples for Approximate Energy Yield Calculations 692.7 Composition of Solar Radiation 692.8 Solar Radiation Measurement 712.8.1 Pyranometers 712.8.2 Reference Cells 712.8.3 Pyranometer Versus Reference Cell Measurements 732.9 Bibliography 763 Solar Cells: Their Design Engineering and Operating Principles 793.1 The Internal Photoelectric Effect in Semiconductors 793.2 A Brief Account of Semiconductor Theory 813.2.1 Semiconductor Doping 813.2.2 The P–N Junction 833.2.3 Characteristic Curves of Semiconductor Diodes 853.3 The Solar Cell: A Specialized Semiconductor Diode with a Large Barrier Layer that is Exposed to Light 863.3.1 Structure of a Crystalline Silicon Solar Cell 863.3.2 Equivalent Circuit of a Solar Cell 873.3.3 Characteristic Curves of Solar Cells 893.4 Solar Cell Efficiency 943.4.1 Spectral Efficiency ηS (of Solar Cells with a Single Junction) 943.4.2 Theoretical Efficiency ηT (of Solar Cells with a Single Junction) 973.4.3 Practical Efficiency ηPV (at a Junction) 1003.4.4 Efficiency Optimization Methods 1043.5 The Most Important Types of Solar Cells and the Attendant Manufacturing Methods 1083.5.1 Crystalline Silicon Solar Cells 1083.5.2 Gallium Arsenide Solar Cells 1113.5.3 Thin-Film Solar Cells 1143.5.4 Dye Sensitized Solar Cell (DSSC; Photoelectrochemical Solar Cells, Grätzel Solar Cells) 1213.6 Bifacial Solar Cells 1223.7 Examples 1223.8 Bibliography 1244 Solar Modules and Solar Generators 1274.1 Solar Modules 1274.2 Potential Solar Cell Wiring Problems 1384.2.1 Characteristic Curves of Solar Cells in all Quadrants 1384.2.2 Wiring Solar Cells in Series 1404.2.3 Parallel-Connected Solar Cells 1474.3 Interconnection of Solar Modules and Solar Generators 1494.3.1 Series Connection of Solar Modules to a String 1494.3.2 Parallel-Connected Solar Modules 1524.3.3 Solar Generators with Parallel-Connected Series Strings 1524.3.4 Solar Generators with Solar Module Matrixing 1594.4 Solar Generator Power Loss Resulting from Partial Shading and Mismatch Loss 1604.4.1 Power Loss Induced by Module Shading 1604.4.2 Mismatch Loss Attributable to Manufacturing Tolerances 1634.4.3 Mismatch Loss Attributable to String Inhomogeneity 1664.5 Solar Generator Structure 1664.5.1 Solar Generator Mounting Options 1664.5.2 Mounting Systems 1764.5.3 Electrical Integration of Solar Generators 1844.5.4 DC Wiring Power Loss 1964.5.5 Grounding Problems on the DC Side 1984.5.6 Structure of Larger-Scale Solar Generators 1994.5.7 Safety Protection Against Touch Voltage 2014.5.8 Factors that Reduce Solar Generator Power Yield 2024.6 Examples 2174.7 Bibliography 2215 PV Energy Systems 2235.1 Stand-alone PV Systems 2235.1.1 PV System Batteries 2255.1.2 Structure of Stand-alone PV Systems 2425.1.3 PV Installation Inverters 2485.1.4 Stand-alone Installation DC Appliances 2585.1.5 Stand-alone 230 V AC PV Installations 2595.1.6 Stand-alone PV Installations with Integrated AC Power Busses 2595.2 Grid-Connected Systems 2625.2.1 Grid-Connected Operation 2625.2.2 Design Engineering and Operating Principles of PV System Inverters 2665.2.3 Standards and Regulations for Grid-Connected Inverters 2775.2.4 Avoidance of Islanding and Stand-alone Operation in Grid Inverters 2885.2.5 Operating Performance and Characteristics of PV Grid Inverters 3025.2.6 Problems that Occur in Grid-Connected Systems and Possible Countermeasures 3475.2.7 Regulation and Stability Problems in Grid Systems 3685.3 Bibliography 3896 Protecting PV Installations Against Lightning 3956.1 Probability of Direct Lightning Strikes 3956.1.1 Specimen Calculation for the Annual Number of Direct Lightning Strikes N D 3976.2 Lightning Strikes: Guide Values; Main Effects 3986.2.1 Types of Lightning 3986.2.2 Effects of Lightning 3996.2.3 Lightning Protection Installation Classes and Efficiency 3996.2.4 Use of Approximate Solutions for Lightning Protection Sizing 3996.3 Basic principles of Lightning Protection 4006.3.1 Internal and External Lightning Protection 4006.3.2 Protection Zone Determination Using the Lightning Sphere Method 4006.3.3 Protection Zone for Lightning Conductors and Lightning Rods 4016.3.4 Lightning Protection Measures for Electricity Installations 4026.4 Shunting Lightning Current to a Series of Down-conductors 4026.5 Potential Increases; Equipotential Bonding 4046.5.1 Equipotential Bonding Realization 4056.5.2 Lightning Current in Conductors that are Incorporated into the Equipotential Bonding Installation 4056.5.3 Lightning Protection Devices 4076.6 Lightning-Current-Induced Voltages and Current 4086.6.1 Mutual Inductance and Induced Voltages in a Rectangular Loop 4096.6.2 Proximity Between Down-conductors and other Installations 4136.6.3 Induced Current 4156.6.4 Voltages in Lightning-Current-Conducting Cylinders 4296.7 PV Installation Lightning Protection Experiments 4326.7.1 Introduction 4326.7.2 The Surge Current Generator 4326.7.3 Test Apparatus for Solar Module Characteristic Curves 4336.7.4 Solar Cell and Solar Module Damage Induced by Surge Current 4356.7.5 Improving Module Immunity to Lightning Current 4396.7.6 Mini-lightning Conductors for PV Installations 4406.7.7 Measurement of Induced Voltage in Individual Modules 4406.7.8 Voltage Induced in Wired Solar Generators 4506.7.9 Conclusions Drawn from the Test Results 4586.8 Optimal Sizing of PV Installation Lightning Protection Devices 4596.8.1 Solar Module Mutual Inductance 4606.8.2 Wiring Mutual Inductance 4616.8.3 Specimen Calculation for MS and Vmax in a Whole String 4626.8.4 Effects of Distant Lightning Strikes 4636.9 Recommendations for PV Installation Lightning Protection 4706.9.1 Possible Protective Measures 4706.9.2 Protection Against Distant Lightning Strikes 4716.9.3 Protection Against Both Distant and Nearby Strikes (up to about 20 m) 4756.9.4 Protection Against Direct Lightning Strikes on PV Installations and Buildings 4766.9.5 Lightning Protection for Large-Scale Ground-Based PV Installations 4796.9.6 Lightning Protection for PV Installations on Flat Roofs 4806.9.7 PV Installation Lightning Protection as Prescribed by Swiss Law 4816.10 Recap and Conclusions 4846.11 Bibliography 4857 Normalized Representation of Energy and Power of PV Systems 4877.1 Introduction 4877.2 Normalized Yields, Losses and Performance Ratio 4877.2.1 Normalized Yields 4877.2.2 Definition of Normalized Losses 4907.2.3 Performance Ratio 4907.2.4 New Normalized Values of Merit 4917.3 Normalized Diagrams for Yields and Losses 4917.3.1 Normalized Monthly and Annual Statistics 4917.3.2 Normalized Daily Statistics Broken Down by Hours 4957.4 Normalized PV Installation Power Output 4957.4.1 Normalized Daily Diagram with Instantaneous Values 4967.4.2 Derivation of Daily Energy Yield from Normalized Instantaneous Values 4977.4.3 Definition of the Correction Factors kG, kT and of efficiency nI 4977.4.4 Assessment Methods Using Normalized Daily Diagrams 4977.4.5 Specimen Normalized Daily Diagrams 4987.5 Anomaly Detection Using Various Types of Diagrams 5027.6 Recap and Conclusions 5067.7 Bibliography 5068 PV Installation Sizing 5078.1 Principal of and Baseline Values for Yield Calculations 5078.1.1 Insolation Calculations 5088.1.2 Determination of the Temperature Correction Factor kT 5088.1.3 Defining the Solar Generator Correction Factor kG 5138.2 Energy Yield Calculation for Grid-Connected Systems 5238.2.1 Examples of Grid-Connected System Energy Yield 5258.3 Sizing PV Installations that Integrate a Battery Bank 5338.3.1 Determination of Mean Daily Appliance Power Consumption 5338.3.2 Requisite Battery Capacity K 5348.3.3 Solar Generator Sizing 5358.3.4 Stand-alone System Sizing Tables 5388.3.5 Sizing Exercises for Stand-alone Installations 5418.4 Insolation Calculation Freeware 5498.4.1 PVGIS Solar Irradiation Data 5508.4.2 The European Satel-Light Insolation Database 5508.5 Simulation Software 5508.6 Bibliography 5519 The Economics of Solar Power 5539.1 How Much Does Solar Energy Cost? 5539.1.1 Examples of More Exact Energy Price Calculations 5559.1.2 Comparison of PV and Conventional Electricity Costs 5579.1.3 PV Electricity Pump Storage System Costs 5609.1.4 PV Electricity Battery Storage Costs 5629.2 Grey Energy; Energy Payback Time; Yield Factor 5629.3 Bibliography 56610 Performance Characteristics of Selected PV Installations 56910.1 Energy Yield Data and Other Aspects of Selected PV Installations 56910.1.1 Gfeller PV Installation in Burgdorf, Switzerland 56910.1.2 Mont Soleil PV Installation in the Jura Mountains (Elevation 1270 m) 57210.1.3 Jungfraujoch PV Installation (Elevation: 3454 m) 57910.1.4 Birg PV Installation (Elevation: 2670 m) 58510.1.5 Stade de Suisse PV Installation in Bern 58810.1.6 Newtech PV Installation with Thin-Film Solar Cell Modules 59210.1.7 Neue Messe PV Installation in Munich, Germany 60010.1.8 Leipziger Land PV Installation 60310.1.9 Borna PV Installation with Biaxial Solar Trackers 60710.1.10 Erlasee Solar Park with Biaxial Solar Trackers 60710.1.11 Guadix PV Installation in Southern Spain, with Biaxial Solar Trackers 60910.1.12 Biaxial Solar Tracker ENEA PV Installation near Naples, Italy 60910.1.13 PV Installation in Mudgee, Australia 61110.1.14 PV Installation in Springerville, Arizona 61210.2 Long-Term Comparison of Four Swiss PV Installations 61410.3 Long-Term Energy Yield of the Burgdorf Installation 61710.4 Mean PV Installation Energy Yield in Germany 61910.5 Bibliography 62011 In Conclusion . . . 623Appendix A: Calculation Tables and Insolation Data 633A.1 Insolation Calculation Tables 633A.1.1 Basic Insolation Calculation 633A1.2 Insolation Calculation Using the Three-Component Model 633A2 Aggregate Monthly Horizontal Global Insolation 634A3 Global Insolation for Various Reference Locations 634A4 R B Factors for Insolation Calculations Using the Three-Component Model 648A5 Shading Diagrams for Various Latitudes 673A6 Energy Yield Calculation Tables 676A6.1 Energy Yield Calculation Tables for Grid-Connected Systems 677A6.2 Stand-alone Installation Sizing Tables 679A7 kT and kG Figures for Energy Yield Calculations 681A7.1 kT Figures for Various Reference Stations 682A7.2 kG Figures for Various Reference Stations 682A8 Insolation and Energy Yield Calculation Maps 683A8.1 Specimen Polar Shading Diagram 683A8.2 Insolation Maps 683A8.3 Maps for Estimates of Annual PV Energy Yield in Europe and Environs 689Appendix B: Links; Books; Acronyms; etc. 691B1 Links to PV Web Sites 691B.1 Organizations 691B1.2 Government Organizations 692B1.3 Research Organizations 692B1.4 Specialized Journals 692B2 Books on Photovoltaics and Related Areas 693B3 Acronyms 695B4 Prefixes for Decimal Fractions and Metric Multiples 696B5 Conversion Factors 696B6 Key Physical Constants 696Index 697

Review copy sent 29/02/12: Book News Review copies sent on 2.2.12 to: ENGINEERING STRUCTURES RENEWABLE ENERGY PHOTOVOLTAICS BULLETIN SOLAR ENERGY JOURNAL OF POWER SOURCES ENERGY RESEARCH REAL POWER SOLAR WIND TECHNOLOGY MODERN POWER SYSTEMS ENERGY AND POWER RISK MANAGEMENT NEW POWER