Building Integrated Photovoltaic Thermal Systems

RSC Energy Series

Basant Agrawal and G.N. Tiwari Building Integrated Photovoltaic Thermal Systems For Sustainable Developments Thermal Systems Building Integrated Photovoltaic Agrawal & Tiwari Building Integrated Photovoltaic Thermal Systems For Sustainable Developments Energy Series

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Titles in the Series: 1: Hydrogen Energy: Challenges and Prospects 2: Fundamentals of Photovoltaic Modules and its Applications 3: Compound Energy Systems: Optimal Operation Methods 4: Building Integrated Photovoltaic Thermal Systems: For Sustainable Developments

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Basant Agrawal and G. N. Tiwari Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi, India RSC Energy Series No. 4

ISBN: 978-1-84973-090-7 ISSN: 1757-6741

A catalogue record for this book is available from the British Library r B. Agrawal and G. N. Tiwari 2011

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For further information see our web site at www.rsc.org Preface

Solar photovoltaic (PV) systems are one of the most promising renewable energy technologies, producing electricity on site directly from solar radiation without harming the environment or depleting materials. The building integrated photovoltaic thermal (BIPVT) system is a technology that merges PV and thermal systems, simultaneously providing both electric and thermal energy. Through this combination, more energy is generated per unit surface area in comparison to the stand-alone photovoltaic system. This book is intended for specialists, scientists and people involved in research in the disciplines of renewable energy, energy studies, building energy or carbon credits. For the practicing professionals, advanced senior or graduate students with work experience, the book should be used as part of an inte- grative programme enabling deep linkages to be made and thus better decisions in the professional world. The work is a summary of the knowledge gained by the authors from the experience of years of research and teaching. The book has been divided into nine chapters. Chapter 1 begins with the fundamental concepts of solar energy and the methodology to determine its availability in terrestrial regions. Chapter 2 reviews the technology for manufacturing silicon and non-silicon photovoltaic solar cells and modules. Chapters 3 and 4 describe human comfort conditions and review passive heating and cooling concepts. Chapter 5 deals with the worldwide installation of photovoltaic systems and a few case studies in this context with regard to BIPVT systems. Chapter 6 deals with thermal modelling, energy and exergy analysis. It shows that the use of BIPVT systems signiﬁcantly increases electrical performance. Chapters 7 and 8 deal with embodied energy analysis, energy payback periods, carbon mitigation and trading. This concludes that the suggested system has a negligible impact on the environment. Chapter 9 provides the techno-economics of the BIPVT system, showing that it has a faster payback time than any traditional system. It is recommended that beginners read Chapters 6 through 9 in the same chronological order as given in the book. SI

RSC Energy Series No. 4 Building Integrated Photovoltaic Thermal Systems: For Sustainable Developments By Basant Agrawal and G. N. Tiwari r B. Agrawal and G. N. Tiwari 2011 Published by the Royal Society of Chemistry, www.rsc.org

v vi Preface units have been used throughout. Appendices and a glossary have also been included at the end of the book. There is no other single book which covers all the basic and the advanced concepts related to the implementation of solar energy for the passive heating and cooling of buildings. In addition, the present book covers the concepts of modelling and analysis of the BIPVT system, which has not been made else- where. All chapters are supplemented with numerous diagrams to understand the concepts better. Anyone who goes through the book cannot miss the enor- mous work that has gone into preparing the text in the present form. We hope that this book will be a milestone in the widespread deployment of solar designed buildings. It is our immense pleasure to express our heartfelt gratitude to the Director of IIT Delhi and Head of CES, IIT Delhi for their kind encouragement. We express our appreciation to the reviewers of this book. We wish to thank all the authors that are represented in the references for granting us permission to reproduce their work. We acknowledge with thanks the ﬁnancial support by the Curriculum Development Cell, IIT Delhi, for preparation of the book. Full credit is due to our publishers, RSC Publishing, Cambridge, UK, for producing the book. We express our deep gratitude to our respected parents for inspiration and their blessings. Not the least, we thank our patient families for their for- bearance during the lengthy process of putting this book together. Comments and suggestions for further improvements of the book can be mailed to the authors at [email protected] or [email protected].

Basant Agrawal G. N. Tiwari Contents

Chapter 1 Solar Radiation and its Availability on Earth 1

1.1 Introduction 1 1.2 The Sun 1 1.3 The Earth 3 1.4 Apparent Path of the Sun 3 1.5 Solar Radiation on the Earth 5 1.6 Variation of Radiation in Extraterrestrial and Terrestrial Regions 7 1.7 Terminology Associated with Solar Radiation 7 1.7.1 Air Mass 7 1.7.2 Diﬀuse Radiation 9 1.7.3 Beam or Direct Radiation 10 1.7.4 Total Radiation or Global Radiation 10 1.7.5 Insolation 10 1.7.6 Irradiance, Radiant Exitance and Emissive Power 10 1.7.7 Latitude 11 1.7.8 Longitude 11 1.7.9 Solar Time 12 1.8 Measurement of Solar Radiation on the Earth’s Surface 12 1.8.1 The Normal Incidence Pyrheliometer 13 1.8.2 The Pyranometer 14 1.8.3 The Sunshine Recorder 15 1.8.4 The World Radiometric Reference 16 1.9 Sun–Earth Geometric Relationship 17 1.9.1 The Declination 17 1.9.2 The Hour Angle 19 1.9.3 The Zenith Angle and the Solar Altitude Angle 19

vii viii Contents 1.9.4 The Slope 21 1.9.5 The Surface Azimuth Angle 21 1.9.6 The Solar Azimuth Angle 21 1.9.7 The Angle of Incidence 22 1.10 Extraterrestrial Radiation on a Horizontal Surface 25 1.11 Radiation on an Inclined Surface 27 1.12 Estimation of Average Solar Radiation 30 1.12.1 Monthly Average of the Daily Total Radiation on a Horizontal Surface 30 1.12.2 Monthly Average of the Daily Diffuse Radiation on a Horizontal Surface 31 1.12.3 Beam and Diffuse Components of Daily Radiation 31 1.12.4 Beam and Diffuse Components of Hourly Radiation 32 1.13 Heat Transfer through Conduction 34 1.13.1 Thermal Conductivity 35 1.13.2 Heat Transfer through Parallel Slabs 35 1.13.3 Heat Transfer through Coaxial Cylinders 36 1.14 Heat Transfer through Convection 39 1.14.1 Dimensionless Heat Convective Parameters 39 1.14.2 Free Convection 41 1.14.3 Simplified Free Convection Relations for Air 42 1.14.4 Forced Convection 42 1.14.5 Combined Free and Forced Convection 43 1.14.6 Convective Heat Transfer Due to Wind 43 1.15 Heat Transfer through Radiation 46 1.15.1 Radiative Heat Transfer Coefficient 46 1.15.2 Sky Radiation 47 References 49 Further Reading 49

Chapter 2 Photovoltaic Technology and its Development 50

2.1 Introduction 50 2.2 Evolution of the Solar Cell 50 2.2.1 Intrinsic Semiconductors 51 2.2.2 Extrinsic Semiconductors 52 2.2.3 p–n Junctions 55 2.2.4 Photovoltaic Cells: Generating Electricity 57 2.2.5 The Limits to Cell Efficiency 61 2.3 Historical Developments 65 2.4 Technology Generation 68 2.4.1 First-generation Technology 68 2.4.2 Second-generation Technology 69 Contents ix 2.4.3 Third-generation Technology 69 2.5 Silicon Solar Cell Materials and Technology 70 2.5.1 Production of Silicon 70 2.5.2 Bulk Monocrystalline Silicon Ingot Production 70 2.5.3 Bulk Multicrystalline Silicon Ingot Production 74 2.5.4 Silicon Wafers 76 2.5.5 Silicon Ribbon and Foil Production 77 2.5.6 Crystalline Silicon Solar Cell Manufacturing Process 82 2.5.7 Thin-film Silicon Cell Approach 83 2.5.8 Transfer Technologies of Monocrystalline Thin Silicon Films onto Glass 84 2.6 Concentrator Photovoltaic Systems 85 2.7 Amorphous Silicon Solar Cells 86 2.8 Copper Indium Gallium Selenide Solar Cells 90 2.9 Cadmium Sulfide/Cadmium Telluride Solar Cells 92 2.10 Dye-sensitized Cells 94 2.11 Organic Solar Cells 96 2.12 Photovoltaic Modules and Arrays for Crystalline Silicon Solar Cells 97 References 101 Further Reading 102

Chapter 3 Thermal Comfort 103

3.1 Introduction 103 3.2 Physical Parameters 104 3.2.1 Air Temperature 104 3.2.2 Relative Humidity 105 3.2.3 Air Movement 105 3.2.4 Mean Radiant Temperature 107 3.2.5 Air Pressure 108 3.2.6 Air Ingredients 108 3.2.7 Air Electricity 108 3.2.8 Acoustics 108 3.2.9 Day Lighting 109 3.3 Physiological Parameters 109 3.3.1 Nutritional Intake 109 3.3.2 Age 109 3.3.3 Ethnic Influences 109 3.3.4 Gender Differences 109 3.3.5 Constitution 110 x Contents 3.4 Intermediate Parameters 110 3.4.1 Clothing 110 3.4.2 Metabolism 110 3.4.3 Adaption and Acclimatization 112 3.4.4 Time of the Day or Season 112 3.4.5 Occupancy 113 3.4.6 Psychological Factors 113 3.5 The Comfort Equation 113 3.5.1 Radiation 116 3.5.2 Convection 116 3.5.3 Conduction through Clothing 117 3.5.4 Evaporative Heat Loss 119 3.5.5 Respiration Heat Loss 120 3.6 Predicting the Thermal Comfort 120 3.6.1 Predicted Mean Vote Index 121 3.6.2 Predicted Percentage Dissatisfied Index 122 3.7 Recent Research and Conclusions 123 3.8 Related Standards 125 References 126 Further Reading 127

Chapter 4 Solar Heating and Cooling Concepts for Buildings 128

4.1 Introduction 128 4.2 Sol-air Temperature 129 4.2.1 Sol-air Temperature for Bare Surfaces 130 4.2.2 Sol-air Temperature for Wetted Surfaces 135 4.2.3 Sol-air Temperature for Blackened and Glazed Surfaces 139 4.3 Passive Solar Heating Systems 141 4.4 Direct Thermal Gain Systems 143 4.4.1 Sol-air Temperature and Heat Transfer for Single-glazed Windows 144 4.4.2 Sol-air Temperature and Heat Transfer for Double-glazed Windows 145 4.4.3 Sol-air Temperature and Heat Transfer for Single-glazed Windows with Reflectors 146 4.5 Indirect Thermal Gain Systems 147 4.5.1 Trombe Walls 148 4.5.2 Water Walls 150 4.5.3 Vented Trombe Walls 151 4.5.4 Phase-change Material Walls 152 4.6 Isolated Thermal Gain or Active Solar Collectors 157 4.6.1 The Thermosyphon System 157 4.6.2 The Barra System 158 4.6.3 Sunspaces 159 Contents xi 4.7 Combined Thermal Gain Systems 159 4.7.1 A Transwall 160 4.7.2 A Solarium 161 4.8 Use of Photovoltaic Arrays as a Façade 163 4.8.1 Semi-transparent Photovoltaic Arrays as a Façade 163 4.8.2 Photovoltaic Trombe Walls 165 4.8.3 Photovoltaic Integrated Phase-change Material Walls 165 4.9 Integration of Photovoltaic Arrays on the Roof 167 4.9.1 Opaque Photovoltaic Arrays Integrated on the Roof 167 4.9.2 Semi-transparent Photovoltaic Arrays Integrated on the Roof 168 References 168

Chapter 5 Implementation of Building Integrated Photovoltaic Thermal Systems and Case Studies 170

5.1 Introduction 170 5.2 Implementation in Germany 171 5.2.1 BIPV Systems on the Rooftop and as a Façade of the Mont-Cenis Academy 171 5.2.2 A BIPV System as a Rooftop in Burstadt 173 5.2.3 A BIPV System as a Rooftop in Muggensturm 174 5.2.4 A PV Façade Integration at Lehrter Station 174 5.3 Implementation in Spain 175 5.3.1 Integration of PV Systems as Parking Cano- pies, Pergolas and Façades at Jaeń University 176 5.3.2 A BIPV System as a Rooftop and Façade at Telefonica Business Park Complex 178 5.3.3 A BIPV System as a Rooftop and Façade at Torre Garena 178 5.4 Implementation in Japan 179 5.4.1 A BIPV System as the Rooftop and Façade of the Sharp Corporation LCD Plant at Kameyama 181 5.4.2 A PV Integrated System on the Louvres of a Roof Shelter in the Itoman City Government Building 181 5.4.3 A PV Integrated Shelter for the Bus and Taxi Terminal at Kanazawa Station 182 5.4.4 The Solar Ark Building at Gifu Prefecture 182 5.5 Implementation in the United States 183 5.5.1 The PV Mounted Roof at Toyota’s NAPCC Manufacturing Plant 184 xii Contents 5.5.2 The PV Mounted Roof at Google Corporate Headquarters (Googleplex) 185 5.5.3 The PV Mounted Roof of the California State University Buildings at Hayward Campus 185 5.5.4 The Farmingdale Rooftop PV System on Long Island 186 5.6 Implementation in Korea 187 5.6.1 A Sun Room Integrated with Semi-transparent PV Modules 188 5.6.2 The BIPV System at the Samsung Institute of Engineering & Construction Technology 189 5.6.3 The PV System on the Parking Lot of Ham- pyeong World Butterfly and Insect Expo 190 5.7 Implementation in Italy 190 5.7.1 The Roof-mounted PV Plant at the Politecni- co di Milano 191 5.7.2 The Roof-mounted System with a Hybrid PVT Façade at Orbassano 192 5.7.3 The PV Modules Installed on the Rooftop in the Town of Serravalle Scrivia 194 5.7.4 The PV Modules on the Warehouse Roof of Coop’s New CNNA-Prato Logistic Centre in Prato 194 5.8 Implementation in the People’s Republic of China 195 5.8.1 The BIPV System on the Shaw Amenities Building of Hong Kong Polytechnic Univer- sity 196 5.8.2 The PV Mounted Roof of the Hong Kong EMSD Headquarters 198 5.8.3 The PV System Integrated with Permanent Buildings at Shanghai World Expo 2010 198 5.8.4 The PV System at the International Garden and Flower Expo Park in Shenzhen 201 5.9 Implementation in Taiwan 201 5.10 Implementation in Australia 201 5.10.1 The BIPV System at Kogarah Town Square 202 5.10.2 The Grid-connected BIPV Power Station at Adelaide Showground 204 5.10.3 The PV System Mounted over the Tilted Roof of the Crowne Plaza Hotel in Alice Springs 205 5.10.4 The PV Integrated Façade over an Eight-story Building at Melbourne University 206 5.11 Implementation in the United Kingdom 207 5.11.1 The Solar Office at Doxford International Business Park 207 Contents xiii 5.11.2 The Cladding PV Modules over the Co-operative Insurance Tower 208 5.12 Installation in India 209 5.12.1 The PV System Mounted on the Roof of the WHO South East Asia Office Building 211 5.13 Recent Research and Conclusions 212 References 215

Chapter 6 Thermal Modelling and Performance Analysis 220

6.1 Introduction 220 6.2 Assumptions 220 6.3 Thermal Modelling 221 6.3.1 A Roof-integrated Opaque PVT System without an Air Duct 221 6.3.2 A Roof-integrated Semi-transparent PVT System without an Air Duct 224 6.3.3 A Roof-integrated Opaque PVT System with an Air Duct 226 6.3.4 A Roof-integrated Semi-transparent PVT System with an Air Duct 230 6.3.5 Façade-integrated PVT Systems with and without a Duct 234 6.4 Overall Performance 234 6.4.1 Net Thermal Output 234 6.4.2 Net Exergy Output 235 6.5 A Case Study of a Roof-integrated PVT System with an Air Duct 236 6.5.1 System Description 236 6.5.2 Observations and Discussion 238 6.6 Optimization by Analyzing Different Configurations 245 6.6.1 Methodology for Analysis 246 6.6.2 Results and Discussion 247 6.7 Case Study of a Façade-integrated PVT System with an Air Duct 253 6.7.1 Thermal Modelling 253 6.7.2 Analysis of the System 255 6.7.3 Results and Discussion 256 6.8 Case Study with a Greenhouse-integrated PVT System 260 6.8.1 System Description 260 6.8.2 Thermal Modelling 262 6.8.3 Results and Discussion 265 6.9 Conclusions 266 References 266 xiv Contents Chapter 7 Life Cycle Energy Analysis 268

7.1 Introduction 268 7.2 Embodied Energy 268 7.2.1 Process Analysis 269 7.2.2 Input–Output Analysis 270 7.2.3 Hybrid Analysis 270 7.3 Life Cycle Metrics 271 7.3.1 Energy Payback Time 271 7.3.2 Electricity Production Factor 272 7.3.3 Life Cycle Conversion Efficiency 273 7.4 Greenhouse Gas Emissions 273 7.5 Energy Payback Time Studies for Photovoltaic Systems: A Literature Review 274 7.6 Energy Content Coefficient for Building Materials 275 7.7 Energy for Masonry Materials 278 7.7.1 Stone Blocks 278 7.7.2 Burnt Clay Bricks 279 7.7.3 Hollow Concrete Blocks 279 7.7.4 Soil–Cement Blocks 279 7.7.5 Steam Cured Mud Blocks 279 7.8 Energy in the Transportation of Building Materials 280 7.9 Energy in Mortars 281 7.10 Energy in Different Types of Masonry 281 7.11 Energy in Different Types of Floor and Roofing Systems 282 7.11.1 Stabilized Mud Block Filler Slab Roof 282 7.11.2 Composite Brick Panel Roof or Floor Slab 282 7.11.3 Reinforced Concrete Ribbed Slab Roof 283 7.11.4 Masonry Vault Roof 283 7.11.5 Ferroconcrete Tile Roof 283 7.12 Energy for Different Types of PV Modules 283 7.12.1 Energy for Silicon PV Modules 284 7.12.2 Energy for Non-silicon PV Modules 285 7.13 Energy for Balance of System 286 7.13.1 Charge Controller 287 7.13.2 Inverter 287 7.13.3 Batteries 287 7.14 Guidelines for Reducing Embodied Energy 288 7.15 Modelling of Embodied Energy for BIPVT Systems 289 7.15.1 Masonry Buildings 290 7.15.2 PVT Systems 290 7.15.3 Balance of System 291 7.16 A Case Study with a Roof-mounted BIPVT System 292 7.16.1 Assumptions 292 7.16.2 Components 292