BARD Offshore 1 Wind Farm, German North Sea

BARD Offshore 1 (BO1) is an operational 400MW offshore wind farm located in the North Sea, around 100km off the coast of Germany.

The project is owned and operated by Ocean Breeze Energy, which is owned by funds managed by Macquarie Asset Management (MAM).

The development of BO1 entailed a total investment of more than €1bn. The project was also supported by the European Commission through the European Energy Programme for Recovery (EEPR) initiative.

The construction of the wind farm began in April 2010, with first power input in December 2010. It was commissioned in September 2013.

BO1 can produce 1.6 billion kWh of energy per year, enough to meet the electricity needs of around 463,000 households.

Location details

BARD Offshore 1 is located north of Borkum Island in the North Sea, around 100km off the German coast.

The farm’s wind turbines are installed at a water depth of up to 40m encompassing an area of approximately 59.2km².

Bard Offshore 1 Wind Farm details

The offshore wind farm consists of 80 BARD 5.0 wind turbines. Each of the 5MW turbines of class 1c features three-bladed rotor with a diameter of 122m.

Each rotor blade is made of plastic on epoxy resin basis with an electronic pitch system. The turbines are fitted with three level gear box and six-pin double fed asynchronous generator.

The height of the hub is 90m and the total height of the structure is 152m.

The wind turbines and tower segment rest on tripile foundations, featuring three piles connected by a transition piece. The cylinder-shaped hollow piles have a diameter of 3.35m and the thickness of the walls varies between 40-120mm.

The piles were placed hydraulically using specially designed Pile Guidance Frame (PGF). Subsequently, cross bracing was laid onto the piles from above and the junctions were grouted with special concrete.

The BARD Offshore 1 project selected the tripile foundation for turbines over tripod, monopile or jack-constructions due to huge water depth, easier construction and low maintenance.

An Offshore Test 1 (OFT 1) was performed within BARD Offshore 1 in 2011 for testing a novel noise protection system. It involved using a Small Bubble Curtain (SBC) that produced small bubbles for noise protection during pile driving beside the piling pipe.

Grid connection

The power generated by the wind turbines is fed into an internal cable system and transformed on site at an offshore high-voltage direct current (HVDC) Light converter station called Borwin Alpha. The wind power is then transported to an onshore converter at Diele 75km from the German coast.

Subsequently, the power is fed into the 380kV German national grid.

The internal grid connection of the wind farm features 12-beam cable network each with four or eight wind turbine generators with 33kV mean voltage.

The offshore transformer features a 4,400-tonne tubular jacket and the topside transformer (upper section) weighing 3,340 tonnes. The two units were then joined by strand jacks.

The platform can accommodate up to 40 people and it is equipped with a helicopter deck. It converts the power into 360kV HVDC before it is transferred onshore.

Key Bard 1 Offshore Wind Farm Contractors

The farm external grid connection was provided by transmission system operator TenneT. TenneT also contracted ABB to build a transmission link to deliver power from BARD Offshore 1 to the German grid.

Harland & Wolff received the fabrication and construction contract for the offshore transformer platform and jacket of BO1. The contract was awarded by Weserwind on behalf of BARD Engineering.

DOC Offshore signed a contract in 2010 to provide construction supervision in the sub-contract ‘Infield cable lay’ as well as package management services.

SGL Rotec supplied the rotor blades, while Cuxhaven Steel Construction made the foundation structures for the turbines.

The cables were delivered by submarine and offshore cables manufacturer NSW. Deep Ocean won the cable laying contract.

German company Offshore Wind Solutions was responsible for O&M at the offshore wind farm.

DLT Engineering supplied and operated a 16 x DL-S588 computer-controlled strand jack system for the self-installation of the central transformer and accommodating platform.

In 2017, a three-year service contract was signed between Energie Baden-Württemberg and Ocean Breeze for technical operation of the residential and transformer platform of BO1.

In January 2018, Acta Auriga, an Ulstein designed XBOW and X-STERN DP2 Service Operation Vessel, was contracted to offer logistical support for Ocean Breeze Energy’s maintenance activities at BARD Offshore 1.

Power Purchase Agreement

RWE Supply and Trading and Ocean Breeze Energy signed a long-term green purchase agreement in April 2023.

Under the agreement, RWE will market the BARD Offshore 1’s electricity under a direct market scheme until 2030. The wind turbines will be transferred to fixed price regime gradually starting 2026.

In future, the wind farm’s electricity will be used at RWE-developed electrolyser projects to produce green hydrogen.