Long-term reliable offshore application of sensor systems

摘要

Biofouling constitutes a problem for the technical reliability of offshore wind farms, because of corrosion damages by boring organisms and increased frictional drag by waves. It is in debate if lab tests and single-site deployment fulfill the requirements to forecast fouling and corrosion at future offshore wind farms. One way to increase evidence may be derive from the greater number in test sites. In order to contribute to this discussion, 14 products used in the marine energy industry as coatings or adhesives were deployed for long-term exposure at five test sites in the North Sea. Focusing on the first 6 months of deployment, it was evident that the mussel-aquaculture of Mytilus edulis influenced the fouling community at Wilhelmshaven located in the Jade estuary. These site specific communities showed the deterioration potential indicated by increasing weight load (up to 375%). Furthermore surface damages, indentions and sub-surface migration in a continuum with a physical displacement up to the removal of materials due to biofouling could be detected within the first six months. The site lighthouse "Alte Weser" exhibiting the highest wave force was also affected by macrofouling. Sylt was influenced by a high abundance of the pacific oysters (Crassostrea gigas). The biofouling community of the samples at Helgoland was dominated by biofilms. The results obtained show that the matrix of test sites chosen was suitable to increase the variability of fouling communities and therefore provide options to model biofouling at offshore sites where new hard substrates will be placed to substrate-free environments in the future. The variability in succession helps to continue the study regarding the deterioration potential of fouling and corrosion.