ADLS (Aviation Detection Lighting System), known as BNK (Bedarfgesteuerte Nachtkennzeichnung) in Germany, enables the red aviation obstruction lights on the top of wind turbines to be switched off except when there are aircraft in the vicinity.


Up till now, the red warning lights flash continuously during hours of darkness. However, environmental concerns about light pollution and the impact of the lights on wildlife (such as bats, birds and insects) have brought about a change of approach.

Why is so much ADLS happening in Germany?

Legislation has been introduced into the updated German Energy Collection Act, which mandates ADLS for all existing onshore wind farms as well as offshore windfarms in the Baltic Sea and in Zone 1 of the North Sea.


The legislation was first introduced in 2018, but the deadline was subsequently extended until the end of December 2023 – meaning that existing wind farms need to be retrofitted with an ADLS system, with work underway before the end of this year. This affects 19 offshore wind farms in the Baltic and North Seas.


New offshore windfarms in the designated areas must include ADLS in their designs.


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What are some of the benefits of using ADLS?

Legislation aside, there are good reasons to adopt this system:

  • reduction in light pollution – lights only illuminated when necessary
  • less energy consumption – being illuminated less often will bring both energy savings and cost savings
  • increased life of lights – reduced need for maintenance or repair during lifetime of turbine
  • less disturbance of environs for aerial creatures
  • aesthetics of sea views (for wind farms close to shore)


How does it work?

ADLS looks for aircraft around an offshore windfarm. When the system determines that an aircraft is approaching the windfarm, it sends a signal for the aviation warning lights to be turned on. Once the aircraft has passed through the wind farm and exited the designated area, the lights are switched off again.


Two different types of aircraft tracker can be used to trigger ADLS: transponders or radars. Our Sabik solution can work with either type, and our lights are both radar- and sensor-agnostic.


Transponder-based ADLS

Transponder-based ADLS makes use of modern technology already installed on aircraft. Transponders continuously send out data such as the aircraft type and name, location and elevation.


A receiver antenna which is positioned within the wind farm gathers information sent from aircraft and sends this to the ADLS server for processing. Once an aircraft is identified as approaching the windfarm and comes within the 4 kilometers, the server sends a command to turn the lights on. The system continuously tracks the path of the aircraft and will turn the lights off again once it has exited the designated area.


Radar-based ADLS

Radar-based ADLS solutions utilize one or two radars located within the wind farm. The radar(s) will continuously scan the surrounding area and send a signal to the server to turn the lights on when an aircraft is detected.


Our aviation obstruction lighting solution for ADLS can be paired with any approved radar system.


What’s next?

For more information please watch ADLS Transponder and ADLS Radar videos. Then contact your regional expert to discuss the relevance of ADLS and its impact on your offshore wind farm.

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SABIK Offshore GmbH | Wilhelm-Maybach-Straße 3 19061 Schwerin

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