Floating Offshore Wind Farms (eBook)

Laura Castro-Santos obtained the title of Industrial Engineering (Energy) in 2009 and her PhD in Industrial Engineering at the Naval and Oceanic Engineering Department in 2013 from the University of A Coruña, where she is currently working as Lecturer in the Department of Naval and Oceanic Engineering. Her current research activities are focused on technical and economic analysis of offshore energy, particularly the floating offshore wind energy. She has collaborated on several research projects focused on mooring and anchoring of offshore renewable energy devices and on the development of the roadmap of the offshore renewable energies in Portugal. She has participated in several international research exchanges: National Energy Laboratory (LNEG), and Centro de Engenharia e Tecnologia Naval (CENTEC) of the University of Lisbon, both in Lisbon (Portugal). She has assisted to a great quantity of teaching and offshore renewable energy courses and international conferences. She has won the research prize “González-Llanos” of naval engineering. Vicente Diaz-Casas is currently an Associate Professor in the Department of Naval and Oceanic Engineering of the University of A Coruña (Spain). His academic and research activities have been strongly linked to the Engineering School of the University of A Coruña (Spain). He received his Master in Naval Architecture and Marine and Offshore Engineering from that university and his Ph.D in Mathematical Methods and Numerical Simulation in Engineering and Applied Sciences through an interuniversity program of University of Santiago de Compostela, University of Vigo and University of A Coruña. He has participated in several international and national research exchanges: Center for Advanced Studies, Research and Development in Sardinia (Sardinia, Italy), University of Auckland (Auckland, New Zealand), Instituto Superior Tecnico, (Lisbon, Portugal), Polytechnic University of Madrid (Madrid, Spain) and CEHIPAR, Towing tank and ship hydrodynamics laboratory of the Spanish Government (Madrid, Spain). He has worked closely with industry; in fact he is currently the coordinator the Naval Architecture division of the Research Group. He has participated in a high number of multidisciplinary and border line research projects. In his research he has combined different approaches and knowledge areas with topics such as artificial intelligent (artificial neural networks and evolutionary computation), computational fluid dynamics, mechanical design and control systems. However his main research topics are ship design and floating structures simulation. Right now his research is focused on simulation and design of floating platform for offshore wind turbines.

Preface 6
Contents 8
Editors and Contributors 9
1 Present and Future of Floating Offshore Wind 17
Abstract 17
1 Introduction 17
2 Offshore Wind Market 19
3 Offshore Wind Fixed Foundations 20
4 Offshore Wind Floating Foundations 22
4.1 Typologies of Floating Platforms for Offshore Wind 22
4.2 Mooring and Anchoring Systems 24
4.3 Existing Floating Wind Concepts 27
4.4 Offshore Wind Turbines 34
5 Market Analysis 36
References 37
2 Life-Cycle Cost of a Floating Offshore Wind Farm 39
Abstract 39
1 Introduction 39
2 General Methodology to Calculate the Life-Cycle Cost of a Floating Offshore Wind Farm 40
2.1 Methodology 40
2.2 Models Selection (MS) 41
2.3 Technical Study (TS) 41
2.4 Maps of the Costs (MC) 42
2.5 Maps of the Economic Indexes (MEI) 42
2.6 Restrictions 43
3 Life Cycle of a Floating Offshore Wind Farm 43
3.1 Definition of the Life-Cycle Process 43
3.2 Breakdown Structure of the Process 43
3.3 Initial Cost Breakdown Structure and Calculation of Costs 44
3.3.1 Definition of the Cost Breakdown Structure 44
3.3.2 Conception and Definition Cost 46
3.3.3 Design and Development Cost 46
3.3.4 Manufacturing Cost 46
3.3.5 Installation Cost 47
3.3.6 Exploitation Cost 48
3.3.7 Dismantling Cost 48
4 Case of Study 48
5 Results 50
6 Conclusions 53
References 53
3 Economic Feasibility of Floating Offshore Wind Farms 55
Abstract 55
1 Introduction 55
2 Methodology 56
2.1 General Procedure 56
2.2 CAPEX and OPEX 57
2.3 Net Present Value (NPV) 57
2.4 Internal Rate of Return (IRR) 58
2.5 Discounted Pay-Back Period (DPBP) 59
2.6 Levelized Cost of Energy (LCOE) 60
2.7 Cost of Power Ratio 60
2.8 Sensitivity 61
3 Case of Study 61
4 Results 63
5 Conclusions 65
References 66
4 Floating Offshore Wind Platforms 68
Abstract 68
1 Introduction 68
2 Hydrodynamics of Offshore Wind Turbine Platforms 69
3 Main Offshore Wind Turbine Platform Concepts 72
3.1 Buoyancy Stabilized Platforms 72
3.2 Mooring Stabilized Platforms 74
3.3 Ballast Stabilized Platforms 76
3.4 Hybrid Platforms and Multi-turbine Concepts 77
4 Evaluation of Platform Concepts 77
4.1 DeepCWind Consortium 79
4.2 Collaborative Comparison Studies in Japan 81
5 Numerical Analysis of Platform Motions 82
6 Floating Offshore Wind Turbine Projects 83
6.1 Projects in Japan 83
6.2 Projects in Europe 85
6.3 Projects in the United States 85
7 Design and Optimization of Floating Offshore Wind Turbine Platforms 87
7.1 Design Standards 87
7.2 Shape Optimization 88
Acknowledgements 89
References 89
5 CFD Applied to Floating Offshore Wind Energy 92
Abstract 92
1 Introduction to CFD 92
2 CFD Simulation of a Wind Turbine 95
2.1 Governing Equations 95
2.2 Movement of the Vanes 96
2.3 Calculation of the Hydrodynamic Forces 96
2.4 Turbulence 97
2.5 Numerical Procedure 98
2.5.1 CAD Design 98
2.5.2 Mesh 99
2.5.3 Boundary and Initial Conditions 99
2.5.4 Calculation Parameters 100
2.5.5 Resolution of the Governing Equations 100
2.5.6 Analysis of the Results 100
3 Conclusions 101
Acknowledgements 101
References 102
6 Mooring and Anchoring 103
Abstract 103
1 Introduction 103
2 Mooring System Configurations and Types of Anchors 104
2.1 Configuration of the Mooring System 104
2.1.1 Spread Mooring Systems 105
Catenary Mooring 105
Multi-catenary 105
2.1.2 Taut Mooring 106
2.1.3 Single Point Moorings (SPM) 106
Turret Mooring 107
Catenary Anchor Leg Mooring (CALM) 107
Single Anchor Leg Mooring (SALM) 107
Articulated Loading Column (ALC) 107
2.2 Anchor Types 108
2.2.1 Gravity Anchors 108
2.2.2 Drag Embedment Anchors 109
2.2.3 Piles 109
2.2.4 Suction Piles 110
2.2.5 Plate Anchors 111
2.2.6 Screw Anchors 111
2.2.7 Free-Fall Anchors 111
2.3 Connectors 112
2.3.1 Shackles 113
2.3.2 Kenter 113
2.3.3 Type H Connector 114
2.3.4 Pear-Shaped Connector 114
2.3.5 Type C Connector 115
2.3.6 Swivel 115
2.3.7 Ballgrah Connector 116
2.3.8 Delmar Connector 116
2.4 Guidance of Mooring/Anchor Application 116
3 Materials and Future Prospects 117
3.1 Mooring Lines 117
3.1.1 Metallic Lines 117
Chains 117
Ropes 118
3.1.2 Non-Metallic Lines 119
Synthetic Fibres 119
Elastomeric Lines 121
3.2 Anchoring Materials 122
3.2.1 Steel 122
3.2.2 Other Materials 122
3.3 Future Prospects 122
4 Requirements and Design Considerations 122
4.1 Functional Requirements 123
4.2 General Design Considerations 124
5 Analysis Methods and Associated Reference Standards 126
5.1 Design by Partial Safety Factor 126
5.2 Probability-Based Design 127
5.3 Reliability Analysis 128
5.4 Connectors 129
6 Discussion 129
Appendix 1: Mooring and Anchoring Guidelines 130
References 132
7 Resource Assessment Methods in the Offshore Wind Energy Sector 134
Abstract 134
1 Introduction 135
2 Global Offshore Wind Resources and European Offshore Wind Market 137
3 Methodologies for Wind Resource Estimation 138
3.1 Wind Masts and Offshore Buoys 140
3.2 Remotely Sensed Data 142
3.2.1 LiDAR Wind Measurement 144
3.3 Numerical Weather Prediction Models 144
4 Wind Resource Assessment 147
4.1 Wind Power Density and Energy Production: Statistical Tools 147
4.2 Wind Power Error Estimation––Uncertainty Analysis 149
5 Present and Future Challenges 150
6 Concluding Remarks 151
Acknowledgements 152
References 152
8 A Spatiotemporal Methodology for Deep Offshore Resource Assessment 155
Abstract 155
1 Introduction 156
2 Wind Resource Assessment Using a Calibration Function 157
2.1 Spatial Calibration—Step A 158
2.2 Spatiotemporal Calibration—Step B 159
2.3 Methodology Evaluation 161
3 Application of the Methodology to the Wind Resource Assessment 162
3.1 Case Study 1—Berlengas: Test of Concept 162
3.2 Case Study 2—Viana Do Castelo: Real Offshore Conditions 165
3.3 The Impact of the Calibration Period on the Wind Assessment Accuracy 170
4 Conclusions 170
Acknowledgement 171
References 171
9 Tools for Ocean Energy Maritime Spatial Planning 173
Abstract 173
1 Introduction 174
2 Offshore Wind Planning—Overview 174
3 Spatial Planning Methodology 176
4 Application of the Methodology—The Portuguese Case Study 179
4.1 Offshore Wind Resource Assessment 180
4.2 Sea Constraints and Restrictions in Continental Portugal 180
4.3 Bathymetry of the Portuguese Continental Platform 181
4.4 Scenario for Fixed and Floating Technology Devices 184
4.4.1 The Near-Shore Technology 185
4.4.2 Deep-Offshore Floating Technology 187
4.5 GIS Interactive Toolbar 187
5 Conclusions 190
Acknowledgements 190
References 190
10 Operation and Maintenance of Floating Offshore Wind Turbines 192
Abstract 192
1 Introduction 192
2 Operation and Maintenance 193
2.1 Fixed Offshore Wind Turbine Structures 193
2.2 Fixed Offshore Wind Turbines 194
2.3 Floating Offshore Wind Turbines 200
3 Conclusion 202
Acknowledgements 202
References 203