It means the Neart na Gaoithe (NnG) wind farm can be fully connected to the National Grid ahead of its 54 turbines being installed in 2023.
NnG covers an area of about 105 square kilometres and will supply enough low-carbon electricity for around 375,000 homes.
The power generated will be exported by NnG’s two offshore substations to its onshore substation, where to access the National Grid’s entry point at Crystal Rig in the Lammermuir Hills, East Lothian.
Matthias Haag, NnG project director, said: “It’s an exciting time for NnG as construction continues both offshore and onshore and we are on track for our first turbines to be operational in mid-2023, with completion of the entire wind farm scheduled for 2024.”
The “rock socket” seabed supports for the foundation jackets were prepared last year by the Saipem 7000 and Saipem 3000 construction vessels in a water depth of about 50 metres, to anchor the offshore substation to the seabed.
Saipem used what is said to be the largest offshore wind installation vessel in the world, the Heerema Sleipnir, to place the 1,100-tonne topside platform on to one of the two foundation jackets.
NnG, jointly owned by EDF Renewables and ESB, is being constructed 15.5km off the coast of Fife.
It will have a capacity of around 450MW and will offset more than 400,000 tonnes of CO2 emissions each year.