At the end of 2013, the decision was made to develop the field, in which Statoil and Statkraft own 75 and 25 per cent respectively. Around 65 wind turbines rated at 6.3 MW will be installed, and electricity generation for transmission to land will start by the end of 2016.
SINTEF's delivery to the first phase of the project was an important part of the data that underlay the decision-making process. During autumn 2013, model tests and computational fluid dynamics (CFD) analyses of wave forces were carried out, as were integrated structural analyses of the wind-turbine.
Wave forces at a depth of 20 metres are difficult to estimate, since such waves are very short and thus extremely nonlinear. In order to reduce uncertainty in the integrated structural analyses, the results of the model tests and the CFD analyses were used to validate the wave forces in the structural analysis. Both fatigue and extreme conditions (wave events with a 50-year return period) were investigated.
In 2014 and 2015, a further three phases of theproject inwhich extreme conditions (50-year waves) were addressed: the first was model tests to investigate wave run-up on the monopile foundations, then a theoretical approach that aimed to improve our understanding of the extreme wave loads, and finally, new model tests to verify estimated wave loads used in the design of the turbines for the Dudgeon wind farm.
According to the project, the final design is made during early 2015.