Periodic Reporting for period 3 - TELWIND (INTEGRATED TELESCOPIC TOWER AND EVOLVED SPAR FLOATING SUBSTRUCTURE FOR LOW-COST DEEP OFFSHORE WIND AND NEXT GENERATION OF 10MW+ TURBINES)
Reporting period: 2017-11-01 to 2018-11-30
• Reduce and optimize the number of materials required for the manufacturing of the floating platform.
• Achieve a simple and industrialize manufacturing and installation processes.
• Ensure full independence of scarce and costly heavy-lift or special purpose vessels during the complete offshore installation process.
• Increase competitiveness by reducing dependency from deep draught ports and scarce installation means.
These objectives were achieved by completing the overall design of the floating platform from a life cycle holistic perspective,where most relevant components and systems were designed,Researching and further detailed design on the two ground-breaking technologies and the opportunities that revolve around them were key to success.One of these technologies is the evolved spar configuration and the ballast tank, which allows taking advantage of inherent benefits of spar platforms without jeopardizing manufacturing and installation process.The second technology is the telescopic tower,which allows for a simpler manufacturing with more conventional means and an optimized transport,also allowing for an easy and streamlined scalability of the system for larger more powerful wind turbines.Finally,when combined,all of these advantages allow for a higher regional impact,which is an important consideration for the regions where offshore wind farms are being implemented,allowing for local communities to retain as much of benefits and the economic push that the floating wind farm can provide. It was found out that about 50% of infrastructure can be procured and built locally,and the remaining 50% can be procured on other European countries.
• Research on the overall hydrodynamic behaviour and detailed structural design of the floating platform
• Cutting edge simulations by building Fully coupled aero-hydro-servo-elastic numerical models
• Design of suspension tendon system plus laboratory testing
• Construction & installation assessment supported by numerical models & tank testing & real-time simulations
• Extensive tank testing campaign in operating & installation conditions
• Detail design of critical & expensive components like moorings & power cables.
• CapEx & OpEx estimate & financial feasibility study for a stand-alone installation and array integration in a multi-megawatt floating offshore wind farm
• Project certification by a internationally well-known reputed certifying institution as TUV SUD.
• Demonstration of scalability by designing a floating substructure for 12MW wind turbine.
In this periodic and final report,the design of the 5MW floating substructurewas finalized based on a detailed structural design and a fully coupled model with a 5 MW reference wind turbine.The upgraded platform enhanced the performance of previous designs avoiding singular events like cable slacking,thus improving the performance of the wind turbine.Mitigation of motions was also profited from the bespoke controller designed for this specific floater.The geometry of the tower was adapted to new envelope of loads.Additionally,the 12MW basic design was successfully finalized,demonstrating the expected easiness for scalability and subsequent cost reduction.Results obtained were contrasted with the 2nd large scale tank testing campaign to fully characterize and validate the dynamic response of the wind turbine.Significant advances have been performed on the design of tendon,upgrading the fatigue life of the tendon system and finalizing the laboratory tests of the suspension cables.Design of mooring system,anchoring and power cables are also an important milestone to complete the overall design from a lifecycle perspective.Once all the analysis and simulations were carried out,the construction,transport and installation procedures were written down and integrated in a global strategy analyzing the impact of weather downtime on the overall deployment at sea.The engineering scope was accompanied by the cost and financial assessment along the project, thus the design was always governed by the financial key parameter indicators.Finally the environmental impact on the offshore site (Great Canary island) was positively addressed,together with estimations on carbon footprint and local content impact. Due to the positive outcomes of these assessments, the social perception to floating wind farm is foreseen favorable.