iWindCr field trial and electrochemical analysis for corrosion detection and monitoring offshore wind turbine's MP-TP steel components

A Proof-of-Concept (POC) low power-low current wireless sensor network (WSN) for corrosion detection and monitoring of offshore wind turbine (OWT)'s component, entitled iWindCr, has been developed and field trialled in one of the OWTs in the UK south region. This paper reports on the setting up and outcomes of this field trial. The trial has successfully demonstrated the working functionality of the WSN by measuring changes of the Open Circuit Potential (OCP) and Zero Resistance Ammeter (ZRA) electrochemical parameters over a period of time. The state of corrosion and estimated life of an M72 galvanised steel stud, part of the Monopile (MP)-transition piece (TP) flanged connection were evaluated using the real-time data from the WSN with reference to the material's corrosion thresholds from the iWindCr database. The paper details the electrochemical analysis processes in relation to the Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarisation Curve (PPC) in addition to the OCP and ZRA techniques. The electrochemical parameters and corrosion threshold values from seawater immersion tests of the steel alloys SS316L and S355, the typical MP-TP materials are presented.