Proof of concept

KIC InnoEnergy AFOSP Project

A prove of concept of a monolithic concrete SPAR platform for FOWT was developed in the framework of the AFOSP KIC-InnoEnergy project (Alternative Floating Platform Designs for Offshore Wind Towers using Low Cost Materials). The AFOSP project consisted in a series of experimental and numerical studies aimed at proving the feasibility of the concept and proved promising CAPEX and OPEX reductions. The membres of the AFOSP consortium are: GNF, University of Stuttgart and UPC.


The experiments comprised a set of hydrodynamic tests performed in the CIEM wave flume facility at the UPC, with a 1:100 scale model assuming Froude similitude.

The complete experimental campaign included free decay tests, a set of 22 regular wave trains of different periods to determine the RAO’s and another set of 21 regular and irregular wave trains in conjunction with a mechanical wind device, simulating the mean thrust force exerted by the wind turbine.

  • experiments1
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Free decay tests 1:100 scaled experiments.

Wind & waves

Wave and wind force experiments, composed in different directions and different wave heights.


Numerical results validated in the CIEM-UPC wave flume.

Numerical studies

Numerical studies were intended to verify that the design is stable when subjected to design load case (DLC) according to the IEC. These studies consisted in coupled dynamic simulations including the mooring system, the controller and the structural dimensions for a particular location, using the certified coupled aeroservo-hydro-elastic code FAST. IEC load situations include different environmental conditions and technical conditions of the floating system including failure cases.


The RAO’s tests were performed in the wave flume where the platform was exposed to several regular wave trains, with a constant 6 cm wave height, and periods from 1.0s to 4.8s.

Hydrodynamic test of a floating offshore structure for wind turbines at UPC Barcelona Tech