NGI maps the foundations for what will be Europe's Largest offshore wind farm
A hundred kilometers from the British coast, developers are building one of the world's largest offshore wind farms. NGI leads the work to understand the ground it will stand on, a subsurface that holds nearly half a million years of climate history.
Offshore wind is an expanding energy source globally. Ensuring that turbines stand safely for generations requires in-depth knowledge of the seabed conditions beneath them. ( Photo: Adobe Stock)
Dogger Bank is a shallow sea area in the middle of the North Sea, known to fishermen for centuries. Now it is becoming something entirely different: one of Europe's most important locations for renewable energy. Dogger Bank South is the newest development in the area, a project that will supply electricity to three million British households.
But for the wind turbines to stand safely for generations, someone must first understand what lies beneath the seabed. This is where NGI comes in.
"Dogger Bank South is a technically demanding and highly engaging project for us," says Carol Cotterill, geoscience expert at NGI.
Cotterill leads NGI's work to develop an integrated geological and geotechnical ground model for the project, the very foundation for all technical decisions about where and how the wind turbines will be placed.
Larger than Oslo
Energy companies RWE and Masdar are developing the Dogger Bank South project in partnership. The project consists of two adjacent areas—Dogger Bank South East and Dogger Bank South West—covering approximately 1,000 square kilometers. Each location is larger than the Oslo municipality.
Developers have planned both fields with an installed capacity of 1.5 gigawatts each, with around a hundred wind turbines in each area. When the facility is complete, Dogger Bank South alone will have a combined capacity of 3 gigawatts, on par with two to three of Norway's largest hydropower plants. NGI has been involved in the Dogger Bank developments since 2011.
Dogger Bank South started in 2024 and has a contract value for NGI of around 38 million kroner over more than three years.
The assignment involves specialists from several of NGI's divisions and technical sections.
Half a million years beneath the seabed
At first glance, Dogger Bank may seem ideal for offshore wind: shallow water, large areas, and stable wind conditions. But beneath the seabed lies complexity.
"The ground conditions reflect an exceptionally long and varied geological history. We're talking about nearly 500,000 years, just within the depths we consider for the foundations," says Cotterill.
The history stored in sediments tells of repeated changes in climate, sea level, and landscapes. The area has been a river delta and periglacial tundra during ice ages. It has been covered by ice, then ice-free, and later characterized by forests, wetlands, lakes, and river mouths as the climate warmed.
"The landscape was eventually flooded by rising sea levels around 6,000 years ago. This created the seabed and ground conditions that today's offshore wind development builds on," explains Cotterill.
The ground model that governs everything
NGI's main task in the project is to develop a comprehensive ground model for foundations and cables in both development areas. The ground model translates geological and geophysical data into an operational picture of the subsurface, an image that constructors, installers, and decision-makers use.
In addition, NGI delivers geotechnical interpretation reports and design basis through a structured program spanning three development phases.
"The work we do is integrated into the development of both wind farms. NGI employees present the project results at national and international conferences, in customer meetings, and to licensing authorities in the UK," says Cotterill.
By combining geological understanding, geophysical measurements, and geotechnical data from laboratory and field, NGI can describe how the subsurface will actually behave under load, not just how it should behave in theory. This is crucial for selecting the right foundation solutions, optimizing design, reducing costs and construction time, and avoiding unwanted incidents during installation.
Renewable Energy Needs Solid Ground
Dogger Bank South is part of the world's most extensive continuous offshore wind development and is closely linked to the UK's and EU's climate goals. To decarbonize energy systems, renewable energy production must scale rapidly and safely.
"The project strongly aligns with NGI's strategic priorities to support the global energy transition through technically leading, research-based solutions," says Cotterill.
For NGI, it is also about strengthening long-term relationships with international customers and partners, and building knowledge about complex ground conditions that can be applied to future offshore and climate-critical infrastructure projects.
"Dogger Bank reinforces NGI's position as a reliable advisor on large offshore wind developments. And it contributes to developing knowledge that will benefit future projects," concludes Cotterill.
