The Universal Foundation Concept Søren A. Nielsen, MBD, Project Manager Lars Bo Ibsen, Aalborg University, Research Professor MBD, brief introduction Development approach Projects The bucket foundation NearshoreLAB Development of UFC Concept philosophy Basic structure Stakeholders Development

MBD Offshore Power A/S R&D company founded in 2001 Present shareholders: * DONG Energy, >50% * MarCon * Novasion Subsidiaries: * NearshoreLAB A/S, DONG Energy 91 % Primary cooperation: * Aalborg University

The challenges Sites are getting larger Geological complex seabeds Focus on reduction of costs Focus on handling of risks, e.g. weather window, availability of construction equipment

The project development approach The look in the rear mirror Only the road you recently travelled Own experiences (try and error) Technology transfer

Development approach Project development  development projects Industrialized product development Project development  development projects Focus on total supply chain Coordinated R&D in each link of the supply chain Active use of feedback Technology transfer is not only using a product in a different location it is adapting technology to new physical environment it is adapting the organisation culture it is adapting the knowledge and education

Development approach Projects versus industry in the offshore wind business Project development Industrial development

Barriers for new offshore technology Lag of focus on technology transfer, understanding of the scope References, track record Large scale demonstrations (few pieces, not whole parks) Handling of risk issues Off cause there is always a small risk when you participate in experimental tooth cleaning, but remember, the treatment is a free offer......!

Projects: The prototype for Pos. 1, Frederikshavn The Ø12x6 m prototype bucket foundation was designed for a Vestas V90 3MW turbine placed on 4 m of water. The design is certified by DNV. The bucket was installed in late 2002 and is in normal operation. The structure/soil interaction has been investigated with sophisticated modal analyse equipment.

Projects: The prototype for Wilhelmshaven E-112 4,5 MW turbine positioned 500 m of the coast outside Hochsiel oil installation Water depth: 4 m. Load regime: Moment > 300.000 kNm, vertical load > 11000 kN, horizontal load > 5000 kN, foundation weight app. 400 tons. Installation April 2005. Try and error. Our conclusion: The installation was jeopar-dized by a impact of the auxiliary vessel during operation outside the predicted wind window. Learning: Plans and procedures to be followed

Projects: The test site, Frederikshavn 25 MW, 5 km of the coast Demonstration of: 6 different ”0-series” turbines 6 different foundation concepts Cabling Scour protection Access systems Power system adaptation Approval for construction: June 2008

UFC philosophy, a framework for project development The UFC is a concurrent process, adding new processes and experiences to a database, used by a configuration methodology to produce the required documentation in each step of the wind farm projects focusing on: The optimal foundation for each turbine position Design is parameter driven Structure based on scaleable modules and elements Production based on series or mass production Installation in widest possible weather window Installation based on common available vessels

The UFC framework

Offshore wind turbine foundations The flexibility of the bucket foundation gives wider range of application. Sites with complex geotechnical properties can be cover by a single foundation concept Platform Bucket Mono pile Tripod

UFC basic foundation principle The bucket foundation (B) is a hybrid combining features from the gravitation platform (A) and the mono pile (C)

Bucket foundation Main objectives Cost reduction, reduction of steel consumption, rational production, smaller installation equipment, reduction of load regime. Risk management, availability of vessels, weather window, seabed condition. Going from “one off” offshore construction to industrialized product, optimised design at each position, parameter driven design, standardized construction elements, standardized installation procedures.

Bucket size variations Different foundation depth with the same wind turbine load. 1:1 buckets increases load taking with (D=diameter) 4. 10 m 20 m 12x12 m 30 m 13x13 m 40 m 14x14 m 15x15 m

Bucket size variations Different penetration depth due to soil condition with the same wind turbine load. Uniform soil 14 x 14 m 18 x 9 m Hard layer

Cooperation UFC development Stakeholders / network AaU: Research professor, 4 Ph.D.s NearshoreLAB DONG Energy Wind turbine industry Construction industry Certifying parties Consultants Cooperation

UFC development projects Description Status Design methodology for bucket foundations, 2001-2002  Prototype reference bucket Frederikshavn, 2002 Prototype reference bucket, Wilhelmshaven 2005  Soil/structure interaction I, integration in FLEX5 / HAWC2 Scour protection in connection with bucket foundations Dynamic behaviour of suction caissons, Ph. D Thesis 2003 - 2007 Static behaviour of bucket foundations, Ph.D. Thesis 2003 - 2007 Soil/structure interaction II, large diameter mono piles 2007 - 2009 On going Physical & numerical modelling of mono piles in silt Ph.D. 2007 – 2010 Offshore installation with Mobile Met Mast bucket foundation, NearshoreLAB, Horns Rev II, UK sites, 2008

UFC development projects Description Status Full scale demonstration bucket i NearshoreLAB, 2008/2009 Application UFC system development, Ph.D. 2008-2010 Planning High tension concrete composite in support structures, Ph.D. 2008 - 2010 Scour protection dynamics, Ph.D. 2008-2010 Advanced probabilistic geotechnical site assessment , 2008 - 2010 Probabilistically modelling of offshore wind farm foundations, 2008 - 2010 Geotechnical site investigation with mobile bucket foundation, 2008

Future UFC development projects Transport and installation system Scanning of penetration path for objects , e.g. stoner, boulders Penetration methods in harder soil and soil anchors Main foundation structures in high tension concrete composite Sub structures in industrialized design

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