TECHNOLOGY AND INNOVATION Substructure design, manufacturing and new concepts

1. TECHNOLOGY AND INNOVATION Substructure design, manufacturing and new concepts INNOVATIONS IN DESIGN AND INSTALLATION OF OFFSHORE WIND TURBINE FOUNDATIONS Stockholm, 2009 September 15th

2. TECHNOLOGY AND INNOVATION Substructure design, manufacturing and new concepts INNOVATIONS IN DESIGN AND INSTALLATION OF OFFSHORE WIND TURBINE FOUNDATIONS THE DRILLED CONCRETE MONOPILE Presented by: Maarten van der Veen Engineering Manager Ballast Nedam Offshore Stockholm, 2009 September 15th

3. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Saudi Bahrein Causeway

4. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Storebaelt Bridge

5. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Confederation Bridge

6. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Offshore Windpark Egmond aan Zee

7. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Rhyl Flats Offshore Windfarm

8. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Gunfleet Sands Offshore Windfarm

9. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Belwind Offshore Windfarm

10. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation Experience steel monopiles • Driven Steel monopiles • Expensive solution due to high and fluctuating steel price • Limited amount of suppliers • Limited production capacity • Drive and drill installation method • High noise impact • Drilled Concrete Monopile • Concrete • Moderate and stable material price • Almost unlimited production capacity • Production can be done locally • Drilled working method • One method suitable for different soil conditions • No or limited noise impact • Monopile weight • Lifting capacity HLV Svanen (8.700 tons) more than sufficient

11. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation R&D: Drilled Concrete Monopile Client: Vattenfall Vindkraft AB; Sweden Location: Kriegers Flak Power: 640 MW Turbine type: 3.6 MW / 5.0 MW Research executed in cooperation with MT Piling (50% Ballast Nedam Company)

12. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation FOUNDATION DESIGN • Performed design activities: • Monopile for 3.6 MW windturbine at water depth of 30m • Monopile for 5.0 MW windturbine at water depth of 30 m • Representative soil profiles: • Profile 1: Sand • Profile 2: Clay • Stability • ULS: section forces, post tensioning and reinforcement • FLS: section forces, concrete • Strength Drillmix • Clamping force drilling machine • Storage concrete ring elements, lifting complete monopile • Concept design concrete ice cone

13. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation FOUNDATION DESIGN • Kriegers Flak (Baltic Sea): I II 3.6 MW 5 MW

14. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation FOUNDATION DESIGN • North Sea (Moderate; Hmax = 11m): III IV

15. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation FOUNDATION DESIGN • North Sea (Extreme; Hmax = 18m): V VI VII

16. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation MT Piling • MT Piling modified the horizontal drilling technique to make it drill vertically. Experience gained in vertical drilling on the following projects which were completed successfully: • Steel pile walls Amsterdam Central Station: - 90 piles Ø 1920 mm, max. length 70 m - no settlements occurred • Ibis hotel Amsterdam: • - 10 piles Ø 1220 mm; length 24 m • Combi pile wall Den Haag: • - 13 piles Ø 1420 mm; length 20 m • City Inn hotel Amsterdam: • - 2 piles Ø 1920 mm; length 20 m

17. Drilling inside and under monopile: Basis Offshore Wind – Design & Construct Offshore Wind – Innovation drillingequipment • Inside monopile • Start drilling process • Soft upper layers • Diameter 5300 mm • Under monopile • Deeper soil layers • Extended cutter head (6700/7100 mm)

18. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation FABRICATION • Fabricationmethod conform • SaudiArabiaBahrainCauseway (1984): • Prefab reinforcementcages • Casting ring elements • Storage and curing ring elements • Monopileassembly • Aligningelements • Grouting element joints • Installation post tensioning • Grouting post tensioningducts • Finishing works: • Installationcutting toe • Installationinjectionlinesfordrillmix • Installationpileplugs

19. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation cost • Assumptions for cost indication: • Production yard in port of Sassnitz • Investment in 2 drilling machines for complete project • Water depth 30 m • Production and installation of complete project (128 foundations) in continuous process • Prefab yard equipped for production of 1 monopile each 2 days; (365 days incl. start-up) • Installation with HLV Svanen (net cycle 48 hr; 256 days) • Excavated soil may be discharged into the sea • Excluding weather downtime

20. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation cost • Total cost per MW as function of amount and turbine type:

21. Basis Offshore Wind – Design & Construct Offshore Wind – Innovation CONCLUSIONs • Design: • The concrete monopile is a technical sound foundation concept • Installation: • The installation of the concrete monopile by vertical tunnelling from HLV Svanen is a technical feasible concept • Foundation weights stay well within limits of HLV Svanen • Cost: • The drilled concrete monopile is economically very competitive, especially for projects consisting of 40 or more foundations • Way forward: • Further study and detailing of concept • Conceptual design certificate – DetNorskeVeritas • Scale test • Project realisation

23. Thank you for your interest www.bn-offshore.com