NEZZY Open sea test 1:10 scaled model

nezzy showed already in laboratory scale that all designed features allow for the aimed LCoE reduction based on innovative floating offshore wind turbine features. At this point nezzy has to be tested in an open sea test as design relevant environment to confirm the results from previous development phases.

Close to Kurahashi, Japan, a test site enables an advanced feasibility study for a 1:10 scaled nezzy. All main components are fabricated and tested in Rendsburg, Germany and afterwards shipped to Japan for the experimental campaign. In parallel, a scaled mooring system and measurement mast was installed onsite. Additionally a fully instrumented model measured the site conditions for wind, wave and current. This scaled wind turbine systems includes a fully operable control system for blade pitch and generator operation. Rotor blades are made of carbon fibre reinforced plastics to meet the scale law in weight, length and aerodynamic performance Gearbox and generator arrangement are tested close to the full-scale design as well as the tower and guy wires. Representing the key feature of nezzy a turret mooring system including a slip ring was tested as well for performance and material use. The self-alignment performed better as expected and nezzy exceeded the proposed energy production.

During the assembly and installation phase the designed methods are tested successfully at less time than expected. In-site towing operation performed additionally, as designed for the full-scale system, including the ballasting phase. Dry weight of the model amounts to app. 3000 kg where additional app. 1500 kg ballast water is added. Finally the measurement campaign provided great data for several system validations and shows an outranging agreement with the design expectations. Completing this project phase nezzy reaches TRL (Technology Readiness Level) 5 with a technology demonstrator in an industrially relevant environment.