Amrumbank West Offshore Wind Farm

Location details

The Amrumbank West wind farm is situated offshore 35km north of the island of Helgoland, Germany. The site lies 37km west of the North Frisian Island of Amrum.

Overall, the project covers an area of over 34km² inside the German Exclusive Economic Zone (EEZ).

The nearest mainland coast is 40km away.

Amrumbank West Project details

The Amrumbank West offshore wind farm is equipped with 80 Siemens SWT-3.6-120 wind turbines. Each of the turbines has an installed capacity of 3.6MW.

The turbines have a rotor diameter of 120m and were installed between 20m and 25m of deep water.

They stand at a height of 90m above sea level supported by 800 tonne steel monopole foundations with a diameter of 6m and height of 70m. All the turbines are interconnected by 33kV infield cables.

The project’s service and operating station is located in Heligoland, Germany.

Amrumbank West will generate renewable electricity for 300,000 households annually, offsetting carbon dioxide emissions by more than 740,000 metric tonnes a year.

Construction

Initially, the research vessel Ice Beam was utilised to conduct soil sample analysis from the site seabed as part of preparations to begin the construction work.

Construction work began in May 2013 after establishing a 500m safety zone around planned outer locations of the region.

The monopile steel foundations, weighing between 80 and 300 tonnes, were driven into the seabed starting January 2014.

MPI Discovery, the six-leg wind turbine installation vessel, was used to transport the steel foundations from the port of Cuxhaven to place them on site. Cuxport crawler crane was utilised to lift the foundation piles into the water from the pier.

The first turbine was installed in February 2015 and the complete wind farm was commissioned in October 2015.

Power Evacuation

The Amrumbank West wind turbines are connected to the transformer station via 100km of array cables.

The wind farm transmits power to the HelWin beta converter platform, located 8km away, using an export cable. Subsequently, the platform transforms the three-phase alternating current (AC) from 155kV to the ±320-kV level and converts it to direct current (DC).

The DC power is then transmitted through a submarine cable via high-voltage direct current transmission HVDC HelWin 2 to the port town of Büsum, located 85km away.

Thereafter, the power travels another 45km to the grid connection point at Brunsbüttel, where the electricity is converted back to three-phase AC.

Offtake agreements

In November 2020, ​ Deutsche Bahn (German Railways) and RWE entered into a 15-year power purchase agreement (PPA).  As agreed, RWE will provide the Deutsche Bahn with renewable energy from the Amrumbank West offshore wind farm from 2024.

In January 2023, RWE announced that its Nordsee Ost and Amrumbank West offshore wind farms will supply 11 German industrial customers and one large municipal utility with green electricity starting 2025 and 2026 respectively.

The agreements were signed between RWE Supply & Trading and Badische Stahlwerke, Freudenberg group, Infraserv Höchst, Mainova, Messer, Schott, Telefónica, Verallia, Vodafone, Wacker and ZF.

Contractors involved

Siemens was contracted to deliver and install its SWT-3.6-120 wind turbines for the Amrumbank West project. The company was also responsible for the maintenance of the turbines for the initial five-year period.

In April and May 2014, Scaldis carried out offshore installation of the Amrumbank West wind farm substation in the German Bight.

Scaldis was engaged in lifting and placing jacket foundation on the seabed, four pile lifts, upending, stabbing and hammering piles to penetration depth; noise mitigation during piling works; jacket levelling, grouting and lifting the topside onto the jacket foundation.

Amrumbank West contracted Sellhorn Ingenieurgesellschaft for planning the time schedule including the assessment of risks due to weather events offshore. Sellhorn was also responsible for document control and scour protection for the monopiles.

MMT (Sweden) conducted the geophysical cable route survey for the project, while Siem Offshore Contractors was responsible for installation of the inner array grid cables and ancillary services.

The armoured 33 kV submarine cables were supplied by NKT Cables.

In 2013, Smulders delivered 80 transition pieces for the Amrumbank West Offshore Wind Farm.

NAUE was engaged to deliver Secutex Soft Rock sand containers for the project.

Avantha Group Company CG installed its transformer substation at the Amrumbank West offshore wind farm. The company designed, engineered, supplied and integrated all critical high-voltage power equipment to connect the 33kV and 155kV networks.

Steel Inspect was responsible for the supervision of coating and repair works of primary and secondary steel parts for the project.

Prysmian Group commissioned HVDC offshore grid connection project HelWin2 in June 2015. HelWin2 connects Amrumbank West with a 690MW cable connection to the mainland Germany land converter station in Büttel.