GREEN SKILLS FOR JOBS Student Book Renewable Energy Technologies NQF Level 4 Introduction to Renewable Energy and Energy Effi ciency Textbook provided free of charge by the Skills for Green Jobs Programme ! For classroom use only! Not for resale or redistribution without further permission! Editor Skills for Green Jobs (S4GJ) Programme Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Registered offices: Bonn and Eschborn GIZ Office Pretoria P.O. Box 13732, Hatfield 0028 Hatfield Gardens, Block C, 1st Floor, 333 Grosvenor Street Pretoria, South Africa Tel.: +27 (0) 12 423 5900 E-mail: [email protected] www.giz.de 1st Edition Responsible: Edda Grunwald Authors: S4GJ Team Illustrations, Layout: WARENFORM Photos: Dörthe Boxberg, Ralf Bäcker, version-foto Pretoria, September 2017 CONTENTS List of Figures and Tables 3 Glossary 12 Preface 26 Foreword 27 Using this Student Book 28 Topic 1 1. Introduction to Renewable Energy Resources and Energy Effi ciency 29 1.1 Economic and Environmental Benefits of Wind Power Systems 30 1.1.1 Wind Power Applications: A Short History 31 1.1.2 Wind Energy Markets in South Africa and the World 41 1.1.3 Advantages and Disadvantages of Wind Power Generation 50 1.2 Economic and Environmental Benefits of Hydrogen Fuel Cell Technology and E-Mobility 61 1.2.1 Hydrogen and Fuel Cell Technologies 62 1.2.2 E-Mobility 75 Topic 2 2. Basic Scientifi c Principles and Concepts 85 2.1 Basic Principles of Wind Power Generation 86 2.1.1 What Causes Wind? 87 2.1.2 Wind Power Factors 94 2.1.3 Essential Wind Turbine Components and their Functions 107 2.1.4 Wind Turbine Types 132 2.2 Basic Principles of Battery and Fuel Cell Technologies 146 2.2.1 Electrochemical Processes in Batteries 147 2.2.2 Electrochemical Processes in Fuel Cells 169 2.3 Basic Principles of E-Mobility 188 2.3.1 Eco-Car Types Compared 189 2.3.2 Essential E-Car Components and their Functions 203 Topic 3 3. Occupational Health and Safety 219 3.1 Hazards and Safe Work Practices Related to Wind Turbine Technologies 220 3.1.1 Hazards Related to Wind Turbine Technologies 221 3.1.2 Safe Work Practices Related to Wind Turbine Technologies 225 3.2 Hazards And Safe Work Practices Related To Fuel Cell Technologies 231 3.2.1 Hazards Related To Fuel Cell Technologies 232 3.2.2 Safe Work Practices Related To Fuel Cell Technologies 237 3.3 Hazards And Safe Work Practices Related To E-Mobility Technologies 242 3.3.1 Hazards Related To E-Mobility Technologies 243 3.3.2 Safe Work Practices Related To E-Mobility Technologies 247 Topic 4 4 Application of Wind Turbine and Fuel Cell Systems and Batteries 253 4.1 Connect Wind Turbine Components using Didactical Training Kits or Small-Scale Industrial Components 254 4.1.1 Experiments with Wind Turbine Training Sets 255 4.1.2 Build your own wind turbine (DIY) 287 4.2 Connect Fuel Cell System Components using Didactical Training Kits 301 4.2.1 Experiments with Fuel Cell Training Sets 302 4.3 Configuring Batteries for Renewable Energy Systems 320 4.3.1 Experiments with Batteries 321 2 LIST OF FIGURES AND TABLES Figures Topic 1 Theme 1.1.1 Figure 1: Simplified drawing (side and top view) of an early vertical-axis windmill 32 Figure 2: A post mill 33 Figure 3: A smock mill 34 Figure 4: A technical drawing illustrating the mechanism for a self-regulating windmill 35 Figure 5: Windpumps at the Loeriesfontein Museum, South Africa 36 Figure 6: A simplified schematic view into a wind turbine 37 Figure 7: A 7 MW offshore wind turbine 38 Theme 1.1.2 Figure 1: Global cumulative installed wind power capacity (2000 – 2015) 42 Figure 2: Top 10 countries with the highest cumulative installed wind power capacity (2015) 43 Figure 3: Large-scale high resolution wind resource map 44 Figure 4: Wind energy projects in South Africa 45 Theme 1.1.3 Figure 1: A possible transition to renewable/clean energy generation over time 51 Figure 2: Comparison of life cycle greenhouse gas emissions for renewable and conventional generation technologies 52 Figure 3: Comparison of life cycle stages and GHG emissions for wind and coal power 53 Figure 4: A typical EIA process for a wind power project (simplified) 56 Figure 5: Main components of a 5 MW wind turbine and their overall share of turbine costs 58 Theme 1.2.1 Figure 1: Comparison of electrolysis and reverse electrolysis of water (schematic) 63 Figure 2: Fuel cell applications in cutting-edge technologies (schematic) 64 Figure 3: Fuel cell operation (schematic and simplified conceptional) 65 Figure 4: Fuel cell in a lab converting chemical energy into electrical energy 65 Figure 5: Hydrogen as alternative fuel powers fuel cell electric cars such as the Toyota Mirai 66 Figure 6: Overview of hydrogen production pathways (simplified) 67 Figure 7: Overview of sustainable hydrogen production pathways (simplified) 68 Figure 8: Illustration of non-sustainable and sustainable hydrogen production techniques 68 Figure 9: Hydrogen is an ‘energy vector’ or ‘energy carrier’ 69 3 Theme 1.2.2 Figure 1: Component configurations in the three different EV-types 76 Figure 2: uYilo’s DC fast charging facility 76 Figure 3: Tesla’s Supercharger charging profile based on 90 kWh models 77 Figure 4: A typical e-bike with rear hub configurations 78 Figure 5: Ratios of electric motor assistance in a pedelec following EU regulations 79 Figure 6: Different electric motor configurations of e-bikes 79 Figure 7: PV shade canopies with integrated public seating and e-bike charging docks 80 Figure 8: Schematic drawing of the first ZEM inland passenger ship FCS Alsterwasser 81 Topic 2 Theme 2.1.1 Figure 1: A rotor spinning fast in strong wind 88 Figure 2: Directions of sea and land breezes along the coast 89 Figure 3: Two different pressure gradient scenarios and their relative effect on wind speed 89 Figure 4: Sixteen principal bearings of wind direction 90 Theme 2.1.2 Figure 1: Mass of air fl owing through swept rotor area (schematic) 96 Figure 2: Volume (V) of the wind ‘cylinder’ can be redefi ned as the swept rotor area (A) multiplied by the length (s) of the wind ‘cylinder’. 96 Figure 3: Relationship between wind speed and wind power 97 Figure 4: Wind speeds and power increase with height 98 Figure 5: The rotor’s swept area 98 Figure 6: Power output increases as the swept rotor area increases 99 Figure 7: Energy transformations relevant to a wind turbine 100 Figure 8: Lift and drag 101 Figure 9: The Betz limit 102 Figure 10: Mechanical and electrical effi ciency 102 Figure 11: Power coeffi cient (Cp) and Poutput vs wind speed 104 Figure 12: Pinput and Poutput vs wind speed 104 Theme 2.1.3 Figure 1: HAWT subsystems (schematic) 108 Figure 2: A single loop conductor placed in a magnetic fi eld (schematic) 109 Figure 3: The conductor rotates in a magnetic fi eld into its horizontal position 110 Figure 4: Flux lines - the pictorial representation of a magnetic fi eld 110 Figure 5: Flemming’s right hand rule 111 Figure 6: Rotating towards its vertical position the conductor is not inducing a current (schematic) 111 4 Figure 7: The conductor rotates into its horizontal position inducing a current in the loop (schematic) 112 Figure 8: The conducting loop is connected to two split rings and two carbon brushes which rest on the slip ring segments 112 Figure 9: Current fl ow under load resistance (schematic) 113 Figure 10: Unidirectional DC current 113 Figure 11: DC machines have many loops of wire wound together to form a coil 114 Figure 12: Types of DC machines (simplifi ed) 114 Figure 13: Schematic diagram of a separately excited DC machine 115 Figure 14: Schematic diagrams of series-wound, shunt-wound and compound-wound generators 115 Figure 15: Schematic diagram of a permanent magnet DC generator 116 Figure 16: Stator assembly for a twin axial fl ux permanent magnet (AFPM) wind turbine 117 Figure 17: Schematic diagram of a synchronous generator and its AC waveform 118 Figure 18: Asynchronous generator diagram and squirrel-cage structure (simplifi ed) 119 Figure 19: Pitch control (simplifi ed) 122 Figure 20: Various blade angles due to pitch control ensuring maximum rated power 122 Figure 21: Pitch control mechanism for a 1 kW wind turbine 123 Figure 22: A typical confi guration for a category A1 installation (schematic and simplifi ed) 124 Figure 23: Switchgear and transformer layout in a typical wind farm confi guration (schematic) 126 Figure 24: Underground cable construction 126 Figure 25: Wind farm power collection system (schematic layout) 127 Theme 2.1.4 Figure 1: Position of principal wind turbine components in HAWTs and VAWTs 133 Figure 2: Principal design comparison of Savonius and Darrieus rotors 134 Figure 3: Comparison of Savonius and Darrieus rotor working principals (schematic) 134 Figure 4: Proposed setups for combined Savonius-Darrieus rotors (schematic) 135 Figure 5: Components of the IKS Windtrainer Junior set in their storage position 137 Figure 6: IKS Windtrainer Junior set: some assembled components 137 Figure 7: Components of the leXsolar-Wind training set in their storage position 138 Figure 8: Two different anemometer types 138 Figure 9: Two different wind machine types 142 Figure 10: Setup for experiment 2 (schematic) 143 Theme 2.2.1 Figure 1: The three basic components of a battery 148 Figure 2: Simplifi ed structure of an atom 149 Figure 3: Sodium cations (Na+) and chloride anions (Cl–) 150 Figure 4: Table salt (NaCl) dissolves in water 151 Figure 5: An enlarged image of Figure 4 c 152 5 Figure 6: The Volta pile (schematic) 153 Figure 7: Simplifi ed electrochemical processes in a voltaic pile / galvanic cell 154 Figure 8: The