Riffgat Offshore Transformer Station

Riffgat Offshore Windfarm is an offshore wind farm located within the German territorial sea to the north-west of the German island of Borkum. The wind turbines are built across an area of 6 square kilometers (2.3 sq mi). It consists of 30 turbines with a total capacity of 113 megawatt (MW), and is expected to generate enough electricity for 112,000 households

Hollandia Strukton JV was awarded with the contract for Engineering, Procurement, Installation and Commissioning (EPIC) of the offshore transformer station (substation). In the substation 33kV infield voltage is transformed to 155kV for export to shore. The two transformers installed on the substation have a capacity of 75MVA each.

The Windpark was connected to the german grid on 11 February 2014, making it the first operational commercial german wind farm

Specifications
• Water depth (LAT): 19.7 m
• Height of cable deck (LAT): 22.5 m
• Height of main deck (LAT): 27.5 m
• Height of helideck: 36 m
• No of wind turbines: 30
• Wind turbine power rating: 3.6 MW
• Wind farm capacity: 108 MW
• Infield voltage: 33 kV
• Export voltage: 155 kV
• Grid connection: 80km 155kV connection to TenneT substation Emden-Borsum
• Type of operation: automatic, unmanned
• Type of topside: fully enclosed, air cooled
• Substructure: jacket type, leg piled
• Transformers: 2 pieces 75MVA two winding transformers, ONANtype
• No of array feeders: 4 times 33kV feeders
• No of export feeders: 2 times 155kV connection to EmdenBorsum substation
• Helideck: suitable for helicopter type AW-139 or equivalent

Completion date:

Client: Offshore-Windpark Riffgat GmbH