IEC TC88 : Wind turbines

1. IEC TC88 : Wind turbines Republic of Korea

2. Outline New Proposal of Korea Status of the WTs in Korea Roadmap of an On/Offshore WTs in Korea Design & Motion Analysis of the FOWT Conclusions

3. New Proposal of KOREA • • To provide uniform methodology for assessment of the floating offshore wind turbine. • • Assessment of design, analysis, installation and maintenance of FOWT for a various types. • This work will aim to bring together expert knowledge from the wind energy and offshore engineering industries in order to formulate a guideline specification of the design, analysis, installation and maintenance requirements for FOWT.

4. New Proposal of KOREA CONTENTS 1Scope 2Normative references 3Terms and definitions 3.1Terms 3.2Definitions 4Symbols and abbreviated terms 4.1Symbols 4.2Abbreviated terms 5General requirements 5.1Fundamental requirements 5.2Safety requirements 5.3Basic considerations 6Design requirements 6.1Introduction 6.2General 6.3Structural Categorization 6.4Design criteria 6.5Accidental loads 7Environmental criteria 7.1Environmental condition 7.2Wind, waves, current 7.3Water depth 7.4Ice 7.5Soil conditions 7.6Marine growth 7.7Earthquakes 7.8Scour 7.9Other environmental conditions • 8Floating offshore wind turbine structure design and analysis • 8.1Introduction 8.2Type of hulls 8.3Hydrostatic stability 8.4Hydrodynamic response analysis 8.5Structural design and strength analysis 8.6Fatigue analysis 8.7TLP design and analysis 8.8SPAR design and analysis 8.9Barge design and analysis 8.10 Other hulls design and analysis 9Mooring system design and analysis 9.1Fundamental requirements 9.2Safety requirements 9.3Design situations 9.4Design criteria 9.5Anchoring systems 9.6Corrosion 9.7Fatigue life 9.8Strength and fatigue analysis 10Fabrication, installation, inspection and maintenance 10.1 Introduction 10.2 Structural fabrication 10.3 Mooring system fabrication 10.4 Transportation 10.5 Installation operations 10.6 Inspection and testing 10.7 Maintenance and repair 11Materials, welding, and corrosion protection 11.1 Introduction 11.2 Steel 11.3 Corrosion protection system 11.4 Nonlinear materials 12Reference

5. Global WIND ENERGY 2000-2030 (in GW) Offshore 150 GW Offshore 40 GW Global offshore wind trend Source : EWEA

6. Economics of Fixed type vs. floating type Source : OTC

7. Resource of Wind Turbine in Korea Energy density[W/m2] Wind velocity[m/s] Water depth[m] Source : KIER Wind Map v1.1 Wind energy(offshore<20m depth)

8. Status of Wind Turbine Market in Korea • Period of 3-5 years in Wind turbine will invest 9 million dollar annually by Korea Government. • Technology development plan for the future Market -“Development of floating offshore wind turbine systems” selected as Strategic Technology by Korea Government • A distribution plan 2.25GW through Wind turbine by 2012. -3MW, 5MWoffshore wind turbine development • Various offshore wind farmInvestment Agreement in progress (MOU).

9. Yanggu 20,000 kW Gangneung 25,000 kW Angang 30,000 kW Yanggu 19,500 kW Daegiri 40,000 kW Daegwanryeong 102,890 kW Gyeonggi 3,000 kW Pyeongchang 19,800 kW Daegiri 2,750 kW Nanjido 100 kW Ansan 3,000 kW Jeongseon 50,000kW Donghae 60,000 kW Ulleung-gun 600 kW Nuaeseom 7,500 kW Hoengseong 40,000 kW Seokbo-myeon 160,000 kW Taebaek 6,800 kW Taean 267,500 kW Yeongyang 18,000 kW Yeongdeok 39,600 kW Gimcheon 200,000 kW KIER 100 kW Saemangeum 22,500 kW Pohang 660 kW Saemangeum 7,900 kW Sajapyeongwon 110,000 kW Miryang 750 kW Sinan 300,000 kW (1st 3MW) Gori 750 kW Yangsan 8,000 kW Jindo 100,000 kW Installed 277,995 kW Prospect WTs 1,630,000 kW Samdal 20,000 kW Dongbuk 20,000 kW Deokcheon 40,000 kW Wolryeong 100 kW Woljung 1,500 kW Hangyeong 30,000 kW Haengwon 9,795 kW Hangyeong 22,700 kW Sangdo 31,500 kW Nansan 14,700 kW Seongsan 20,000 kW Cheongsuri 3,000 kW Pyosyeon 20,000 kW Gapado 27,000 kW Godeok 20,000 kW Status of Wind Turbine Market in Korea Installed wind farm Being installed wind farm

10. R&D Roadmap of Wind Turbine in Korea Main Target 1st Stage 2004~2007 Technology development and Industrialization 2nd Stage 2008~2012 Technology Accumulation 3rd Stage 2013~2018 Creating new Industry Medium sized System Commercialization / Component Development Large System Development /Component Localization and Expert Large System Export/ Commercialization of Application technology Onshore System Site Searching Large scale Wind Farm Development Wind farm Construction in Asia Component Localization and Export Site testing & Supplying Medium Sized Systems Pioneering abroad Market for components Component Analysis and Design 750kW – Site test 2MW – Design and Manufacturing 2MW – Site test Offshore System 2MW Remodeling and Manufacturing 2MW – Site test Multi MW class Offshore Wind turbine Supply Pioneering abroad market for Components Offshore wind turbine Component Design Component Localization 3MW Design and Manufacturing 3MW – Site test 3MW – Concept Design 5~6MW Design and Manufacturing 5~6MW – Site test Large Offshore wind farm Searching Large scale Offshore Wind Farm Development Small System Supply Small Sized Systems Pioneering abroad market for Components 10kW Manufacturing 10kW-Site test Hybrid System Development 100kW Design and Manufacturing 100kW-Site test

11. Analysis Models(Plan)

12. Basic Requirement • - Turbine Capacity, Motion Requirement • Environmental Condition • - Water depth, Wind, Current, Wave, Ice etc Design Basis Hydrodynamic Analysis Initial Design Structural Analysis Global/Local Strength Fatigue Analysis Conceptual Design Framework • Hydrodynamic Data • - Wind Load, Current Load • - Motion Analysis : Motion RAO, Force Transfer Function • Time Domain Analysis • - Platform Motion : Angular Displacement, Acceleration • - Mooring Line Tension • Hull Sizing • Mooring System • Loading Condition • Stability Check • Prediction of Motion Characteristics

13. Analysis Methodology & Procedures CRITICALMOORING LINEREMOVED STATICMOORING SYSTEMDISPLACEMENTSAND TENSIONS STEADYENVIRONMENTAL LOADS YES YES DAMAGECONDITION(incl. TRANSIENT)ANALYSIS ? DESIGNENVIRONMENTALCONDITION VESSELSLOW FREQUENCYMOTIONS TIME DOMAINLINETENSIONS NO VESSELSWAVE FREQUENCYMOTIONS DYNAMICCONDITIONANALYSIS ? DYNAMICSTUDY NO ANALYSISCOMPLETED

14. Design Basis

15. Design Basis of WT Platform Horizontal Motion Limits Rotational Motion Limits Acceleration Limits Simple Geometry Minimizing Heave Motion Pretension Offshore Platform Type = ? Number of Mooring Lines Displacement

16. TLP Type Total Weight Topside weight Steel Weight Fixed Ballast Displacement Draft VCG VCB GMT,L Radius of Gyration (@ COG) Rxx Ryy Rzz Mooring Line Characteristics No. of Line Dia. Elasticity Modulus MBL

17. Results – Motion time Series(TLP)

18. SPAR Type Total Weight Topside weight Steel Weight Fixed Ballast Displacement Draft VCG VCB GMT,L Radius of Gyration (@ COG) Rxx Ryy Rzz Mooring Line Characteristics No. of Line Dia. Elasticity Modulus MBL

19. Results – Motion time Series(SPAR)

20. Characteristics of floating offshore WT for each types TLP Type TLP • Horizontal Motion, surge mode, has to be improved to meet excursion • limitation which is generally 5% of water depth in offshore field • Vertical motions are too good to be true • Motion criteria, especially acceleration at the location of nacelle will be • needed at the early design stage • KG is higher than KB SPAR Type SPAR • Permanent eccentricity is to be counter-balanced by the arrangements • of the fixed ballast • Simple structure • KB is higher than KG • Lowered KG by fixed ballast

21. Conclusion • At present, the technology of a floating offshore wind turbine is not established and studying continuously. • Experts need to create a new standard to compare the calculation data of floating offshore wind turbine for various load cases. • A new standard should be dealt with by experts separately(>IEC 61400-3)

22. Thank you!