BARD Offshore I Wind Farm, North Sea, Germany

BARD Offshore I is a 400MW offshore wind farm, its construction began in March 2010. The project is located around 100km north-west of Borkum Island in the North Sea, covering an area of about 60 square kilometres.

Power generated by BARD Offshore I

The offshore wind farm will be installed with a total of 80 Bard 5.0 wind turbines, capable of serving the energy needs of up to 400,000 households. It will result in annual cut down of 452,061t of CO₂ emissions. The project is expected to be complete by 2013.

The power generated by the wind farm will first reach the Borwin I (Alpha) Offshore Platform, where it will be transferred to Diele onshore substation, 75km from the coast.

The substation will further feed it to the 380kV German national grid. It has received a €53.1m ($65m) grant under the European Energy Programme for Recovery (EEPR) from the European Commission.

The project is owned by SudWestStrom Windpark (70%) and KNK Ocean Breeze (30%). BARD Engineering is the developer.

Installation of turbines at the German wind farm

The turbines have a rated capacity of five megawatts each and are being installed at water depths ranging from 40m to 44m.

The foundation of each turbine weighs 239t and is a tri-pile structure, consisting of three pylons and one transition piece. Each pylons weighs 72t. The ancillary structures weigh 23t.

The piles are 90m high and are laid 40m underwater, with a further 30m inserted into the seabed. The hub height of the turbines above water is about 90m. The rotor blades measure 122m in diameter.

The turbines are being installed using several jack-up barges, such as the Barges Windlift, JB 115, JB 117 and Thor. The crews at the project site are transported and provided offshore access by Amplemann system, which is a self-stabilising platform attached to the VOS Sympathy vessel.

As of January 2012, 30 of the 80 turbines have been installed. By March 2012, the foundation work on 50 turbines was complete. A total of 16 turbines are currently operational and are generating electricity.

Grid connection for BARD Offshore I

Power generated from BARD Offshore I will be first transmitted to the Borwin I (Alpha) Offshore platform and then to Diele substation onshore, from where it will be supplied to the European grid.

The AC transformer at the Borwin I (Alpha) Offshore platform will convert the power into high-voltage direct current (HVDC) before transmitting it to the German power grid through a 200km cable line.

Suppliers to the German North Sea-based project

The platforms for offshore access for the crews are being provided by Ampelmann. The platforms were placed on the VOS Sympathy vessel provided by Vroon.

The transformer station used for BARD Offshore I was built by Bard Group and Netherlands-based marine services provider Jack-Up Barge. Jack-Up Barge also provided the JB 115 and JB 117 jack-up barges for the installation of the turbines and rotors. Thor, the other jack-up barge, was provided by Hochtief Solution.

The pylons and ancillary structures required for installing the tripile foundations are being provided by BLRT Grupp/Marketex. SGL Rotec is responsible for supplying the rotor blades for the wind farm under a five year contract.

The foundation structures for the project were produced by Cuxhaven Steel Construction in 2008. ABB was contracted for providing the design, supply, installation and engineering for the offshore converter. The sea and land cables were also installed by ABB.

The transition pipes were built and supplied by EEW Special Pipe Constructions.