Seagreen 1A Surveys

First geotechnical surveys completed for TotalEnergies and SSE’s offshore wind project

The first geotechnical seabed surveys for TotalEnergies and SSE Renewables’ 500 MW Seagreen 1A offshore wind farm in Scotland have been completed. Phase two of the geotechnical works is expected to commence later this year and should take around two weeks to complete.

Credit: GEO

Seagreen 1A lies adjacent to the existing 1,075 MW Seagreen project and represents approximately 500 MW of additional renewable energy generation capacity.

The project’s second phase could see an additional 36 wind turbines installed off the Angus coast, added to the 114 Vestas V164-10.0 MW units already fully operational at the wind farm, increasing its capacity to 1,575 MW.

The vessel that carried out the first phase of the geotechnical campaign, the 90-meter-long Connector, arrived on site and completed the works in ten days in February.

This involved specialist cone penetrometer testing (CPT) at almost 100 locations.

Using dynamic positioning (DP) technology the vessel repeatedly held positions while thin rod sensors penetrated into the seabed at depths of up to 15 meters to allow the team to learn more about the seabed composition and understand if the proposed turbine foundation locations are suitable and appropriate for the technology proposed.

The second phase, which is expected to commence later this year, will involve vibrocore works along the proposed export cable route from the offshore site to the landfall at Cockenzie.

“We are pleased to confirm the completion of another geotechnical offshore survey at the Seagreen 1A site. This builds on existing site data and is another step forward in the project following the unanimous support from East Lothian Council in the approval of the onshore substation design last year,” said Andrew Train, Project Director for Seagreen 1A.

Fully operational since October 2023, Seagreen is Scotland’s largest wind farm as well as the world’s deepest fixed-bottom offshore wind farm, with its deepest foundation installed at a record 58.7 meters below sea level.

The wind farm is owned by TotalEnergies and SSE Renewables. At the end of last year, TotalEnergies decided to sell a 25.5% equity stake in Seagreen to Thailand’s national oil and gas company PTTEP. The completion of the transaction is subject to receipt of applicable governmental and regulatory approvals.