4OO Star Wind Floater – Basis for development Floating Offshore Wind - Existing concepts- Limited amount of existing concepts. Many of them seems non-realistic.WindSeaIdeolBlue H TLPHYWINDSwayWindFloatDr.techn.Olav Olsen – Development of OO Star Wind Floater- Demand for cost effective and realistic concepts – “Simple, Safe, Robust and Cost Effective”OO StarHybrid SemiHIPRWindSteel SemiOO StarConcrete SemiOO StarSteel Semi
5OO Star Wind Floater – General Description The OO Star is a robust, stable and very simple floater concept.Water depth potential from m (subject to environment)Can be built in concrete, steel or a combination (hybrid). Material selection according to optimal design, cost, fabrication facilities etc.Concrete material typically for harsh environment, large turbinesSteel typically for small/medium turbines, more benign watersCombination of concrete and steel to fulfil special requirementsThe OO Star consists of a central shaft supporting the WTG, and a tri-star shaped pontoon supporting 3 buoyancy cylinders for optimal stability.In principle the permanent buoyancy is in the columns and shaft. The pontoons provide structural support of the bucket cells, weight stability, added mass and temporary buoyancy for inshore assembly.The OO Star can be fabricated in a dock, on a barge or on a quay. The structure is well suited for modular fabrication.The full substructure can float with very small draft and the unit can be fully assembled at quay-side before tow to site. No requirements for deep waters or expensive heavy lifting offshore.
6OO Star – Tuning of geometry The following main parameters can be adjusted to fulfil requirements with regard to motions and stability:DraftCentre distance columnsDiameter bucket cells and shaftPontoon width, variations along pontoonsPontoon height, variations along pontoonsBilge keel – extension of base slabCompartments in corner cellsFull concrete floater with extended base slab
7OO Star Wind Floater – Why Concrete ?? A concrete version of OO Star is robust and flexible, can be sized for large turbines by changing simple parametersConcrete hull - clean and simple configurationSimple ballast system, piping from central shaftOptimal structural stiffness and dynamic characteristicsNot fatigue sensitiveMaintenance free hullLong design life, 100+ years (reusable)For a concrete floater the elevation for the interface between substructure and tower can be adjusted upwards to reduce fatigue in the steel tower.
8OO Star Wind Floater – Why Concrete (contd.) ?? Potential for low production cost through mass production and industrialization, worldwideBuild-up of “new” supply chain different from offshore- and shipyardsLocal content, can be fabricated anywhereHigh number of potential fabricators can build these units (relatively low tech.) – improved competitionEnvironment friendlySo far OO Star has been developed for 3 MW and 6 MW WTG. Can be sized for 10 MW or larger.
9OO Star Wind Floater – Why Steel ?? Industry culture in particular countriesSteel yard availability and efficiencyShip type structure – stiffened platesLighter structure, simple handling inshoreVery shallow draft inshoreSuitable for small or medium size turbines
10First phase hydro dynamic analyses OO Star Wind FloaterFirst phase hydro dynamic analysesHydrodynamic analyses by WADAM and SIMO to calculate heave and pitch periods in addition to floater responseUsed for tuning of conceptual design by calibrating spread sheet calculationsFLOATGEN - SIMO simulation
11First phase structural analyses OO Star Wind FloaterFirst phase structural analysesFEA to evaluate stress distribution in shaft/ pontoon interfaceUsed for establishing a sound connection detail during conceptual design.
12OO Star Wind Floater – Ongoing Activities OO Star Wind Floater – ConcreteConcrete semisubmersible wind floater, 6 MW WTGSupported by Research Council of NorwayTotal budget 9 MNOK, RCN grants 4,5 MNOKSchedule: (2 years)Project owner: Dr.techn.Olav Olsen ASPartners: IFE Kjeller, Statoil and AccionaScope: Develop Basic Design for North Sea conditionsFLOATGEN – SteelSteel semisubmersible wind floater, 3 MW WTGEC-project with total budget 36 M€, EC grants 19 M€Schedule: (4 years)Project split in two parts: Gamesa windfloater and Acciona windfloaterPartners in Acciona group: Acciona, Navantia and Olav OlsenScope: Design, build and install a floating wind turbine, demo unit in Spanish waters in 2016OO-scope: Develop floater technology, detail design of floater