Monobase Wind has concluded the model testing in MARIN successfully. All tests were in line with their predictions for all stages of the transport, installation and in-place situations.
The transportation analysis showed mild accelerations (less than 1.1 m/s2) at nacelle height, even at 6 m significant wave height (12 m maximum waves). This is due to the own period of the Monobase being greater than 20 seconds and the first order movements are therefore not sensitive for waves in the southern part of the North Sea (mostly 4-8 sec waves). The Monobase also moves within acceptable limits during the installation procedure, with wave limits of 2m (10sec) and/or 2.5m (8 sec). This will allow the operational crew to choose the weather window with the required flexibility. Specifically the lowering of the 'donut' was much better controllable than we had expected. The donut slows down several meters before engaging with the tower mat and gently sets itself on top of it. The deceleration can be designed for any specific circumstances by tuning the space between 'donut 'and 'tower column'. The in-place simulated a 100 year storm in 45 metres water depth, resulting in maximum waves of 32 metres, which the Monobase was able withstand. Next steps for the company is to execute detailed studies for clients, to design the Monobase for specific locations, environmental conditions and turbine specifications.
