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

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

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

7. Resource of Wind Turbine in Korea
Classification
Unit
Onshore
Offshore
Theoretical
Potential
TWh/y
987
881
Capacity GW
369
309
Area
km2
97,545
79,539
Geographical 99
176 37 62
9,755
15,908
Technical 49 88 18 31
4,877
7,954
Water depth[m]
Wind velocity[m/s]
Energy density[W/m2]
Wind energy(offshore<20m depth)
Source : KIER Wind Map v1.1

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, 5MW offshore wind turbine development
• Various offshore wind farm Investment Agreement in progress (MOU).
Company
Location
Capacity
Timeframe(year)
KUMHO industrial.
Jeonnam Yeosu city
￦2000 billion
KOSPO(Korea southern power co.ltd)
Busan city
350 MW
KHNP
(Korea hydro & nuclear power co.ltd, Doosan)
Jeju city
30MW
DONGKUK S&C
Jeonnam Shinan(Bigeum-island)
90MW
Target by 2013
POSCO
Jeonnam Southwestern Sea
600MW
Target by 2015
HANWHA E&C
Incheon-City Muui-Do(Island)
2.5 MW * 39
1step by 2012

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

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

11. Analysis Models(Plan)
Model No. 1 2 3
Platform Type
TLP
Spar
Barge
Stabilized by
Tether Tension
Ballast
Buoyancy
Position Keeping
Taut Catenary
Slack Catenary

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

13. Analysis Methodology & Procedures
STEADY ENVIRONMENTAL LOADS
DESIGN ENVIRONMENTAL CONDITION
VESSELS LOW FREQUENCY MOTIONS
STATIC MOORING SYSTEM DISPLACEMENTS AND TENSIONS
VESSELS WAVE FREQUENCY MOTIONS
TIME DOMAIN LINE TENSIONS
DAMAGE CONDITION (incl. TRANSIENT) ANALYSIS ?
CRITICAL MOORING LINE REMOVED
DYNAMIC CONDITION ANALYSIS ?
ANALYSIS COMPLETED
DYNAMIC STUDY
YES NO

14. Design Basis Rotor Environment (survival) Nacelle Mass(ton) Tower
Diameter [m]
Maximum RPM
Maximum Tip Speed [m/s]
Shaft Tilt [degree]
Rotor Mass [ton]
Nacelle Mass(ton)
Tower
Height [m]
Diameter – bottom [m]
Diameter – top [m]
Thickness – bottom [mm]
Thickness – top [mm]
Mass [ton]
Overall CoG Location
(above tower bottom, m) X Y Z
Environment
(survival)
Significant Wave height
Wind Speed
Water Depth
Current Speed
Tide
Topsides
Platform Weight
Topside Weight
Draft
Motion
Maximum Angular Motion
Tower Top Acceleration

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 )

22. Thank you!