Wave and Tidal Energy

Deborah Greaves is Professor of Ocean Engineering and Director of the COAST (Coastal, Ocean and Sediment Transport) Laboratory at University of Plymouth and is Board Member and Inaugural Chair for PRIMaRE (the Partnership for Research In Marine Renewable Energy, www.primare.org). Her research interests include marine renewable energy, physical and numerical modelling of violent free surface flow and fluid-structure interaction. She leads and has led a number of research projects concerning marine renewable energy in collaboration with industrial and academic partners. She has published over 125 peer-reviewed papers, has secured 3.9 million research income as PI, is a Chartered Engineer and Fellow of the Institution of Civil Engineers, a Member of RINA (Royal Institution of Naval Architects), and a member of the technical committee for EWTEC (European Wave and Tidal Energy Conference), a reviewer for UK Research Councils, for several journals, and was shortlisted for the 2014 WISE Research Award. Gregorio Iglesias (GI) is Professor of Coastal Engineering at University of Plymouth and Leader of the COAST (Coastal, Ocean and Sediment Transport) Research Group. He has over 20 years' experience in numerical and physical modelling applied to Marine Renewable Energy and Coastal Engineering, including the characterisation of wave and tidal resources, and the modelling of coastal morphodynamics accounting for the effects of wave and tidal farms. He participates in the design and laboratory tests of WECs and coastal and port structures, and acts as PI on research grants and contracts funded by the European Commission, various national research councils, coastal management agencies and port authorities. He is a member of the IEC Technical Committee for sub-prototype size wave energy device development (laboratory testing) and one of the inventors of the WaveCat, a floating overtopping WEC. Professor Iglesias has published over 100 peer-reviewed papers and secured over 5M research income.

List of Contributors xviii Foreword xx Acknowledgements xxi 1 Introduction 1 Deborah Greaves and Gregorio Iglesias 1.1 Background 1 1.2 History of Wave and Tidal Energy 3 1.3 Unknowns and Challenges Remaining for Wave and Tidal Energy 5 1.4 Synopsis 11 References 12 2 The Marine Resource 15 Gregorio Iglesias 2.1 Introduction 15 2.2 The Wave Resource 15 2.3 The Tidal Stream Resource 31 Acknowledgements 47 References 47 3 Wave Energy Technology 52 Deborah Greaves 3.1 Introduction 52 3.2 Fundamentals 56 3.3 Hydrodynamics of Wave Energy Conversion 64 3.4 Classification of Wave Energy Converters 73 3.5 Oscillating Water Columns 76 3.6 Overtopping Systems 83 3.7 Oscillating Bodies 85 3.8 Other Technologies 95 3.9 The Wave Energy Array 95 References 97 4 Tidal Energy Technology 105 Tim ODoherty, Daphne M. ODoherty and Allan Mason]Jones 4.1 General Introduction 105 4.2 Location of Operation 105 4.3 Environmental Impacts 106 4.4 Tides 107 4.5 Tidal Range Generation 108 4.6 Tidal Stream 111 4.7 Types of Devices 126 4.8 Oscillating Hydrofoils 129 4.9 Venturi Effect Devices 130 4.10 Other Devices 130 4.11 Computational Fluid Dynamics 132 4.12 Security, Installation and Maintenance 138 4.13 Worked Examples 141 References 146 5 Device Design 151 Lars Johanning, Sam D. Weller, Phillip R. Thies, Brian Holmes and John Griffiths 5.1 Standards and Certification in Marine Energy 151 5.2 Reliability 161 5.3 Moorings and Anchors 169 5.4 Foundations 178 References 185 6 Power Systems 191 Andrew R. Plummer, Andrew J. Hillis and Carlos Perez]Collazo 6.1 Introduction to Power Take]Off Systems 191 6.2 Electrical Generators 194 6.3 Turbines for WEC Power Take]Off 200 6.4 Hydraulic Power Transmission Systems 206 6.5 Hydraulic PTO Designs for WECs 212 6.6 Direct Mechanical Power Take]Off 214 6.7 Control for Maximum Energy Capture 215 6.8 Electrical Infrastructure and Grid Integration 221 6.9 Summary of Challenges for PTO Design and Development 229 References 230 7 Physical Modelling 233 Martyn Hann and Carlos Perez]Collazo 7.1 Introduction 233 7.2 Device Development and Test Planning 234 7.3 Scaling and Similitude 234 7.3.1 Scaling MRE Devices 239 7.3.2 Common Problems Scaling MRE Devices 240 7.4 Model Design and Construction 241 7.5 Fixing and Mooring 247 7.6 Instrumentation 248 7.7 Model Calibration 258 7.8 Modelling the Environment 264 7.9 Test Facilities 271 7.10 Recommended Tests 274 References 283 8 Numerical Modelling 289 Thomas Vyzikas and Deborah Greaves 8.1 Introduction 289 8.2 Review of Hydrodynamics 292 8.3 Numerical Modelling Techniques 310 8.4 Numerical Modelling of Water Waves 325 8.5 Commonly Used Open]Source Software 331 8.6 Applicability of Numerical Models in MRE 346 References 351 9 Environmental Effects 364 Gregorio Iglesias, Javier Abanades Tercero, Teresa Simas, Ins Machado and Erica Cruz 9.1 Introduction364 9.2 Wave Farm Effects on the Wave Field 364 9.3 Wave Farm Effects on Coastal Processes 391 9.4 Tidal Stream Farm Effects on Hydrodynamics and Sedimentary Processes 414 9.5 Marine Biota 415 9.6 The Environmental Impact Assessment 425 References 443 10 Consenting and Legal Aspects 455 Anne Marie OHagan 10.1 Introduction 455 10.2 International Law 456 10.3 Regional Law 462 10.4 EU Law and Policy 464 10.5 National Consenting Systems 478 10.6 Gaps and Opportunities 499 Acknowledgement 504 References 504 11 The Economics of Wave and Tidal Energy 513 Gregorio Iglesias, Sharay Astariz and Angela Vazquez 11.1 Individual Costs 513 11.2 Levelised Cost 518 11.3 Externalities 522 References 526 12 Project Development 533 Paul Vigars, Kwangsoo Lee, Sungwon Shin, Boel Ekergard, Mats Leijon, Yago Torre]Enciso, Dorleta Marina and Deborah Greaves 12.1 Introduction 533 12.2 Alstom Ocean