First Jacket In at Deepest Fixed Bottom Offshore Wind Farm

The first wind turbine jacket foundation has been installed at the 1.1 GW Seagreen, Scotland’s largest and the world’s deepest, fixed bottom offshore wind farm, SSE Renewables said.

Two jackets operated by main contractor Seaway 7 made their way on a barge from Global Energy Group’s Port of Nigg in the Highlands of Scotland to the site 27 kilometres off the coast of Angus, arriving on Wednesday, 6 October.

The barge was met by the Saipem 7000 – the semisubmersible crane vessel which is used to lift each of the 2,000-tonne jackets.

The maiden voyage marked the start of works for a GBP 3bn joint venture between SSE Renewables and TotalEnergies. SSE Renewables is leading the development and construction of the project, supported by TotalEnergies, and will operate Seagreen on completion.

The installation campaign marks the first-ever gigawatt-scale deployment of suction caisson technology to fix offshore wind turbine foundations to the seabed, the developer said.

Several barges will work in continuous rotation with each other carrying two jackets from Nigg to the offshore site before returning to Nigg for replenishment. Each journey from Nigg out to site will take approximately 36 hours depending on the weather.

114 jacket foundations will be installed at the site in total. Each jacket foundation will support a Vestas V164-10 MW turbine.

”It is fantastic to get our campaign to install all 114 wind turbine foundations in underway and on schedule for what will be the world’s deepest, fixed bottom offshore wind farm,” Paul Cooley, Director of Capital Projects at SSE Renewables, said.

”More than 50 people are involved each time the barges head out to site including the on-shore team, ballast engineer, tug captain, crew, riggers, welders, tow master, and pilot.”

The overall turbine foundations installation campaign is supporting over 140 jobs at Port of Nigg, according to SSE Renewables.

”It is testament to the skill of our project team and all our contractors including our Scottish and UK supply chain that we have been able to get to this landmark point,” Philippe de Cacqueray, Head of Offshore Wind UK at TotalEnergies said.

”Scotland’s energy transition is beginning to accelerate, and we have taken another important step towards the Net-Zero goal. TotalEnergies is delighted that Seagreen has now installed the first jacket at what will become Scotland’s largest offshore wind farm.”

Seaway 7 is the engineering, procurement, construction and installation (EPCI) contractor for the wind farm’s foundations and inter-array cables

”The installation of the first Seagreen jacket is a momentous milestone for everyone involved in the project, only 16 months after contract award and a testament to the hard work of the thousands of people bringing Seagreen to life across the supply chain,” Lloyd Duthie, Managing Director EPCI Projects at Seaway 7, said.

”We’ll continue the jacket installation campaign through 2021 and 2022 as we lay Seagreen’s foundations. Later this year our cable lay vessels will start the installation of the inner array grid cables. These cables will connect the network of turbines and transport future electricity generated by the wind turbines to the offshore substation – ready for transport onshore.”

First power is expected by early 2022 with the offshore wind farm expected to enter commercial operation in 2023.