The offshore wind farm already has its own Wikipedia page. ‘Neart Na Gaoithe’ (meaning ‘strength of the wind’ in Gaelic) has an area of 105 square metres, is thirty kilometres off the coast and fifty metres deep, located just north of the Scottish city of Torness. An additional challenge is that the wind farm must be built on a partly rocky and partly muddy seabed which is not a particularly easy location for constructing a wind farm. But that’s how it works nowadays; there was still some space there. Because of the busy marine traffic, a large wind farm cannot simply be installed just anywhere in the North Sea. Furthermore, pipelines and electricity and internet cables have been run almost everywhere over the seabed.
In 2009, the initial idea for the wind farm was: 125 units of the 3.6 MW wind turbine or 75 units of the 6 MW wind turbine, which would collectively generate 420 to 450 megawatts of electricity. Enough to simultaneously supply half a million households with electricity. Eventually, the French EDF Group obtained the permit for the wind farm and issued a concept study for other parties, ultimately won by Iv-Offshore & Energy together with General Electric (GE).
“We first took a fresh look at the original design”, says Fedor. “A consideration was whether we should opt for one or two transformer platforms. Two is more expensive, but on the other hand...if it’s decided to build only one substation, for example, longer cables will be needed to connect all the wind turbines to the central platform. And those cables aren’t exactly cheap either. For several reasons, EDF preferred the option of two smaller platforms with the lightest and simplest possible design”, says Fedor. “After all, the lighter the platform, the cheaper and the easier it is to install. To put the platforms and wind turbines in place, a crane vessel must be reserved during the study phase, two years in advance. With the chosen concept, the turbine foundations and the platforms can be installed using the same ship, considerably limiting the contractual risk for the customer.”