Marine Bioanalytical Chemistry

OffChEm Project 2017 - 2021

Chemical emissions from offshore wind farms – Potential impacts on the marine environment and their evaluation

Aerial view of an offshore wind farm

© Sabine Billerbeck

The ongoing development of offshore wind energy in the North Sea and Baltic Sea has an increasing impact on the marine environment. More than 1,000 offshore wind turbines and at least 20 converter and transformer platforms have already been installed. Every offshore installation represents a disturbance in the marine environment. Chemical emissions from these farms have hardly been investigated to date. In this context, necessary measures for corrosion protection systems and the use of operating materials need to be considered. Scientific findings on the quantities released and their distribution in the respective environmental compartments (water, sediment, biota) are currently scarce. A comprehensive assessment of the effects on the marine environment is therefore only possible to a limited extent by the current state of knowledge.

Focus on corrosion protection

Galvanic anodes (so-called "sacrificial anodes") are used to protect offshore constructions against corrosion, whereby large quantities of metal compounds (in particular compounds of aluminium and zinc) are continuously emitted into the marine environment. In addition to the main components, galvanic anodes also contain other metallic by-products (e.g. indium, lead, cadmium and other heavy metals), which are also released into the marine environment during the consumption. In addition, a wide range of polyurethane/epoxy resin-based coating materials are used for surface corrosion protection in the offshore sector. These coatings may contain organic substances which are released into the marine environment during operation due to weathering of the surfaces and leaching from the coatings. They therefore represent an additional potential source of pollution for the North Sea and the Baltic Sea.

Aims of the project

In this project, funded by the Federal Maritime and Hydrographic Agency (BSH), the HZG investigates the following aspects in collaboration with the BSH:

  • Identification of potential organic and inorganic (harmful) substances which could have a relevant impact on the marine environment through the corrosion protection of offshore wind farms.
  • Development of analytical methods and suitable sampling strategies to determine the emissions of the potential substances in the various compartments in the vicinity of offshore wind farms.
  • Evaluation of the relevance of the identified potential pollutants on the basis of their chemical emissions from offshore wind farms and their influence on the local and regional marine environment.

25.07. – 05.08.2016: In a first survey the surrounding of different offshore wind farms in the North Sea close to the coast line were sampled with the research vessel "Ludwig Prandtl" (HZG).

31.05 – 06.06.2017: In the course oft he BSH monitoring with the research vessel Atair first test samples were taken inside offshore wind farms and from areas that are planned to become offshore wind farms in the future.

17.07.-19.07.2017: Sampling campaign in the wind farm "DanTysk" and areas close to Sylt’s coast line. The aim was to gain insights into the influence of singles wind turbines on water currents and turbulences. In addition water samples were taken for the analysis of trace metals.

10.04.-16.04.2018: A first high-resolution sampling of different offshore wind farms in the North Sea was accomplished with the research vessel "Atair" (BSH). In total, at more than 50 sampling stations water, sediment and particulate matter samples were taken.

05.03.-14.03.2019: For insights into temporal changes in pollution load samples stations from previous sampling campaigns were sampled again. In total almost 100 water, sediment and particulate matter samples were taken in and around offshore wind farms in the North Sea. More on this campaign in these blog posts (in German):

Messkampagne auf der "Atair"

Messkampagne auf der "Atair" - Zweiter Anlauf

Impressions from sampling campaigns


Publications


Theses


Nathalie Voigt 2017:
Multielementcharakterisierung von Anodenmaterial für den kathodischen Korrosionsschutz an Offshore-Strukturen mittels ICP-MS/MS.
Bachelorarbeit, FH Lübeck.

Svenja Meers 2018:
Untersuchung der Elementverteilung in Oberflächensedimenten aus dem Umfeld ausgewählter Offshore Windparks im küstennahen Bereich der Nordsee.
Bachelorarbeit, FH Lübeck.