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Offshore wind farm - BARD Offshore 1

BARD Offshore 1

BO1, the first and 2017 most productive offshore wind farm in Germany is completely connected to the grid since September 2013.

80 wind energy generators of the 5 megawatt class reach a nominal capacity of 400 mega watt - this equals the energy consumption of more than 400,000 households.

BARD Offshore 1 was supported by the European Commission within the scope of the European Energy Programme for Recovery (EEPR).

At a glance

Area 59.2 square kilometre
Water depth up to 40 metre
Turbines 80 BARD 5.0 wind energy converter of the 5 megawatt-Class
Foundation Tripiles
Rotor diametre 122 metre
Hub height 90 metre
Total height 152 metre
Total power 400 megawatt
Start of construction April 2010
First power input Dezember 2010
Commissioning September 2013

Turbine technology BARD 5.0

  • 5 MW Offshore turbines of class 1c with a rotor diameter of 122 m
  • three roter blades made of plastic on epoxy resin basis with an electronic pitch system
  • drive train with main bearing and hollow rotor shaft
  • three level gear box und six-pin double feeded asynchronous generator

The tripile technology is especially engineered for far offshore installation

Description

  • Wind turbine and tower segment are mounted on a tripile foundation consisting of three piles connected trough a transition piece.
  • Total height of a single pile varies between 84 and 91 m, depending of the exact location within the wind farm.
  • The zylinder shaped piles are hollow and its diametre is 3.35 m. The thickness of the walls varies between 40 and 120 mm depending on the soil conditions and the location within the farm.
  • For errection, the piles are hydraulically hammered into the mud by using the especially desgined Pile Guidance Frame (PGF).
  • In the next step the cross-bracing is laid onto the piles from above and the junctions are grouted. The grout material is a special concrete which is molded into the space between the bottom end of the cross bracing's pins and the top end of the piles.
  • Thegrouted connection is optimised through shear keys.

Advantages

  • Advantages of the tripile foundation over tripod, mono pile or jack-constructions are:
  • Especially designed for huge water depth and far offshore installation.
  • Simple and easy to errect construction, most parts of the errection occur above the water line.
  • Low maintenance effort, most work to be executed above the water line.
  • Easy to adjust to different locations (water depth, load, etc.) through change of the pile geometrics.

Technology converter platform BARD 1 – HVDC Platform Borwin Alpha

Farm external grid connection

  • Provided by the grid operator TenneT
  • High-voltage, direct current (HVDC) electric transmission system (voltage 360 kV)
  • Platform is named Borwin Alpha

Farm internal grid connection

  • 33 kV mean voltage, 12-beam cable network each with 4 or 8 WTGs
  • Transformation to 150 kV

Converter platform BARD 1

  • Accomodation for up to 40 people, equipped with a heli deck

Our environmental monitoring

In the context of the approval process of a wind farm in the German exclusive economic zone the potential issues affecting the sea environment have to be examined. Furthermore it is required by law to execute an environmental impact assessment. To fullfill theses two obligations a so called Environmental Monitoring is installed. Method and range are determined by the permit authority, the Bundesamt für Seeschifffahrt und Hydrographie (BSH).

All phases of a project's lifecycle (planning, construction, operation, decommissioning) are included within the Environmental Monitoring and ranges each within different time frames. In the planning phase data of a minimun of two years needs to be included, in the operating phase a minimum of three years. This periods can be extented by the permit authority BSH up to a maximum of five years.

Subject of protection, to be examined in the monitoring, are benthos, fish, avifauna, bats and maritime mammals. Due to the long time periods and big efforts costs for environmental monotoring are quite high, several million Euros.