Amrumbank West

Location and Ownership

The Amrumbank West offshore wind farm is located in the North Sea, Germany, approximately 35 km north of the island of Helgoland and 37 km west of the North Frisian island of Amrum. It is situated inside the German Exclusive Economic Zone (EEZ), with the nearest mainland coast being about 40 km away. The project is owned by RWE Renewables, with Amrumbank West GmbH being a wholly-owned subsidiary of RWE Renewables.

Capacity and Turbines

The wind farm has an installed capacity of 302 MW, generated by 80 Siemens SWT-3.6-120 wind turbines. Each turbine has a rated power of 3.6 MW and a rotor diameter of 120 meters, with each rotor blade being 58.5 meters long.

Construction and Timeline

Construction of the Amrumbank West wind farm began in May 2013, although the actual installation of the turbines started in January 2014. The first turbine was installed in February 2015, and the entire wind farm was commissioned in October 2015. The project was initially delayed by 15 months due to the lack of power lines.

Infrastructure and Foundations

The turbines are installed on 800-tonne steel monopole foundations, each with a diameter of 6 meters and a height of 70 meters. These foundations are driven into the seabed, which is between 20 and 25 meters deep. The turbines stand at a height of 90 meters above sea level. The seabed protection involved initially using a layer of large stones, which was later replaced by geotextile containers filled with sand to prevent erosion.

Power Transmission and Grid Connection

The electricity generated by the wind farm is transmitted to the 690 MW HelWin2 offshore converter station through 8 km of cables. The HelWin2 converter station, built by Heerema Fabrication Group and Siemens, uses Siemens' HVDC PLUS technology to transform the electricity into high-voltage, low-loss direct current. This electricity is then transferred via an 85 km export cable to a landing point near Bussum, and from there, a 45 km spur line connects it to the onshore coastal converter substation at Buttel, where it is converted into alternating current and fed into the grid.

Environmental Impact and Energy Production

The Amrumbank West wind farm generates enough renewable energy to power approximately 300,000 households annually. It offsets more than 740,000 metric tonnes of carbon dioxide emissions each year, although some sources specify the CO2 savings as 432,278 tonnes annually.

Contractors and Maintenance

Key contractors involved in the project include Siemens Gamesa Renewable Energy, which supplied and installed the turbines and is responsible for their maintenance for the initial five years. Other contractors include Scaldis for the installation of the wind farm substation, Sellhorn Ingenieurgesellschaft for planning and risk assessment, and various other companies for cable installation and survey services.

Power Purchase Agreements

RWE has entered into several power purchase agreements (PPAs) for the energy generated from Amrumbank West. For example, in November 2020, RWE signed a 15-year PPA with Deutsche Bahn to supply renewable energy starting from 2024. Additionally, RWE will supply green electricity to several German industrial customers and a municipal utility starting from 2025 and 2026, respectively.