Buchan Offshore Wind

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Our role
Project challenges
Our approach
Key successes
Project legacy

Our role
Project challenges
Our approach
Key successes
Project legacy

Markets

Power & renewables
Services

Engineering & design
Location

Aberdeenshire, UK
Client

Buchan Offshore Wind Ltd

Andrew Hart

Technical Director, Ground Engineering & Tunneling , Epsom, UK contact form

Buchan Offshore Wind is at the forefront of delivering commercial scale floating offshore wind in the UK. With the early selection of project partner BW Ideol’s proven Damping Pool® floating foundation technology, and a commitment to manufacture them in concrete in Scotland, the project will be pivotal to catalysing the Scottish floating offshore wind supply chain.

The near 1GW wind farm, comprising up to 70 turbines on floating foundations, will generate enough secure and stable home-grown energy to power more than one million homes, contributing significantly to the UK’s long term energy security. Located 75km north-east of Fraserburgh, and connecting to the grid at Peterhead, the project is projected to support 2,900 jobs during construction and deliver more than £2 billion in economic value to Scotland over its lifetime.

Our role

AtkinsRéalis was appointed in August 2022 to provide geophysical and geotechnical services to the Buchan project team. This comprised support with the design, management and supervision of the marine geophysical, geotechnical and benthic surveys, followed by integration and interpretation of the acquired data and development of an integrated ground model for the project. To complete this work, AtkinsRéalis mobilised a team of technical specialists who worked collaboratively with the client, their marine survey contractor and other project stakeholders, including offshore in the North Sea.

Project challenges

As part of the early stages of the project, the client needed to determine the ground conditions across the site to inform the consenting process, including ‘Rochdale Envelope’ assessment – a planning tool that identifies maximum and minimum parameters for a design, ensuring the final iteration falls within a defined ‘envelope’, as well as the early concept design for the anchors that would be needed to hold the floating turbines in place. This required the completion of offshore and nearshore geophysical, geotechnical and benthic surveys of the project area (array area and export cable corridor) and development of a preliminary integrated ground model for the project area.

The key challenges faced at this stage of the project, included:

Understanding the complexity and variability of the geological ground conditions across the project area.
Identifying the geohazard risks and geo-engineering constraints that would influence the engineering design, construction and operation of the offshore windfarm, as well as the potential mitigation measures.
Safely conducting offshore geophysical, geotechnical and environmental surveys in the North Sea. Completion of the surveys required mobilising five survey vessels over an eight-month period.
Collaboration between all those working on the project, to ensure safe completion of all tasks, especially when working offshore.

Our approach

To help meet the Client’s requirements, an integrated multi-disciplinary project team of technical Ground Engineering specialists from AtkinsRéalis, collaborated with the client’s project team on the following workstreams:

Completed an in-depth Desk Study of the project area, as well as an optioneering study to identify the preferred offshore and onshore export cable corridor using an innovative AtkinsRéalis designed GIS-based toolkit to assess the geological, topographical, bathymetrical, environmental, social and engineering constraints, as well as the cable landfall.
The scoping and specification of the offshore geophysical, geotechnical and environmental surveys, as well as geotechnical lab testing.
Assisted the client through the tender process, including reviewing tender submissions and interviewing survey contractors.
Managed all offshore and nearshore survey operations, providing a dedicated offshore client representatives on each of the five survey vessels used, and coordinating daily with contractors and the client to ensure safe, efficient delivery.
Worked with 6 Alpha Ltd to complete an unexploded ordnance (UXO) Threat and Risk Assessment, informing and optimising survey planning and securing health and safety (ALARP) certification for all survey locations.
Reviewed the survey contractor’s outputs, including data, reporting and seabed survey data model (SSDM) geodatabase.
Integrated and interpreted all collected data to develop a preliminary ground model, including soil province and profile mapping and initial geotechnical interpretation.
Assessed the geohazards and geo-engineering risks present across the project area and identified potential mitigation measures.
Worked collaboratively with the client’s floating anchor design and consenting teams, to provide parameters for a ‘Rochdale Envelope’ planning assessment.
Completed a cable protection study to understand seabed mobility, scour risks and required protection measures along the offshore export cable corridor.

Key successes

On completion of the surveys, the AtkinsRéalis team reviewed the survey deliverables and developed a Preliminary Integrated Ground Model for the project area, as well as a combined Ground Model and Geotechnical Interpretative Report. The project close-out workshop was held in the AtkinsRéalis Lava Lab – an immersive collaboration space where participants could fully understand the project deliverables and data.

AtkinsRéalis played a pivotal role during this early phase of the project, providing Buchan Offshore Wind with the necessary ground-related information they needed to submit their consenting application to the Scottish Ministers in August 2025, which included applications for consent under the Electricity Act 1989 and Marine License applications under the Marine (Scotland) Act 2010.