Seagreen offshore wind project phase one will comprise two wind farms with maximum combined capacity of 1,500MW. Image courtesy of SSE.
Seagreen offshore wind project is fully owned by SSE. Image courtesy of Richard Klein.

Seagreen offshore wind project is planned to be developed in two phases in the Firth of Forth  Development Zone of North Sea, Scotland, UK.

The project is being developed by Seagreen Wind Energy (SWE), a wholly-owned subsidiary of the Scottish energy company SSE.

The first phase of the Seagreen offshore wind project will consist of two wind farms with up to 1.5GW of combined installed capacity.

The first two wind farms, named Seagreen Alpha and Seagreen Bravo, will together generate electricity that will be enough to supply for approximately 670,000 Scottish households.

Seagreen Wind Energy plans to start the project development after securing a favourable strike price for both the wind farms in the upcoming UK‘s contracts for difference (CFD) auction, which is expected to take place in mid-2019.

Seagreen wind project development

The Crown Estate awarded Seagreen the exclusive wind power development rights in the Firth of Forth Zone of Scottish North Sea in January 2010.

Seagreen received environmental approval for the Alpha and Bravo offshore wind farms in 2012.

The Scottish Ministers granted consent for the construction of Seagreen phase one comprising two 525MW wind farms equipped with 75 turbines each, in October 2014.

The project received marine license from the Scottish Natural Heritage in 2017.

In March 2018, Seagreen submitted an application to the Marine Scotland seeking amendments to the original consent of 2014, to increase the combined maximum capacity of the two wind farms to 1,500MW, while using fewer but more powerful turbines.

The optimised wind farm design was approved by the Scottish Ministers in August 2018.

In September 2018, Fluor sold its 50% stake in Seagreen Wind Energy (SWE) to SSE, making SSE the sole owner of the project.

Seagreen phase one site details

The Seagreen phase one will occupy 391km² in the northern portion of the Firth of Forth Development Zone of Scottish North Sea in water depths ranging from 40m to 60m, while the Seagreen phase two is proposed to be developed in the south-eastern area of the zone.

Seagreen Alpha and Bravo wind farms will be located at a distance of 27km and 38km respectively from the Angus coastline, Scotland.

Seagreen Alpha and Seagreen Bravo wind farms make-up

The Seagreen Alpha and the Seagreen Bravo wind farms will cover 197km² and 194km² respectively.

Each wind farm will be equipped with up to 70 three-bladed horizontal axis turbines mounted on monopile foundations at a distance of minimum 1km from each other.

The wind farms will have a maximum of 120 turbines in both the sites.

The rotor diameter and blade tip height for the turbines will be up to 220m and 280m respectively.

The turbines of the wind farms will be interconnected with up to 325km of inter-array cables. The electricity generated by both the wind farms will be transmitted onshore through export cables connected to up to five offshore substation platforms.

The project will also include up to six meteorological masts and six wave buoys.

Power transmission from the Seagreen wind project

Up to six export cable trenches with a total length of 530km are proposed for the project.

The export cables will make landfall at Carnoustie on the Angus coast, from where the electricity will be further transmitted to the national grid through an onshore export cable connecting to a new substation at Tealing located north of Dundee.

Contractors involved

Hogan Lovells acted as an advisor for Fluor to sell its 50% interest in the wind power project to SSE in September 2018.