Dogger Bank Wind Farm Substations

SSE Renewables, Equinor and Vargronn are investing £9 billion in a joint venture to build the world's largest offshore wind farm. The wind farm, consisting of three projects, is expected to produce enough energy to power 4.5 million UK homes.

The overall contract was completed by ABB, and Doran Consulting Limited led the design team for the three Dogger Bank sites.

The station buildings are steel framed structures with reinforced concrete fire wall enclosures constructed around each transformer area. The steelwork frame has been designed to suit the various equipment loadings and deflection limits. Careful detailing of the earthing requirements was essential for this ‘energised’ building.The form of the roof structure varies from roof rafters to fabricated trusses, depending on the spans and loading requirements. The maximum height to eaves in the Valve Hall is approximately 17 m, with a clear span of 24m. The ground conditions consist of highly compressible clays which led to a detailed geotechnical analysis using Plaxis 3D to mitigate against long-term settlement.

The ancillary buildings are located around the converter station and the AC switchyard and Reactor Area. These comprise of a spare transformer base, spare parts building, Auxiliary Transformer building, AC kiosk building, DNO transformer building and MV transformer buildings. The AC switchyard design involved detailed foundation design for resistors, surge arrestors, earth switches, circuit breakers and disconnectors. A concrete cable trench and numerous buried conduits were required to service this equipment and a closely spaced copper grid was required to meet the earthing requirements.