Belgian corrosion protection systems designer Elsyca has created a cathodic protection system for the self-installing concrete gravity based wind turbine foundation structures to be used for the first time at the 41.5MW Blyth Offshore Demonstrator Project.
Royal BAM Group has been awarded a contract by EDF Energy Renewables via SPV Blyth Offshore Demonstrator Ltd, to design, fabricate and install five full-size gravity base foundations for wind turbines at the demo site.
The prototype foundation structures will be pre-fabricated onshore, then towed to the Blyth deployment site where they will be filled with sand/water mixture for lowering them onto a pre-installed gravel bed.
Prediction of the long term efficiency of the corrosion protection system is essential because any survey of the monopile inside the concrete caisson is impossible, Elsyca said.
A correct design of the cathodic protection system and the installation of monitoring devices are crucial for securing the integrity of the monopile during the 26-year service life.
A sacrificial anode system was designed for both internal and external corrosion protection purposes, Elsyca said.
Elsyca’s CPMaster simulation platform was used for the in-depth analysis of the long-term cathodic protection effectiveness.
A first design was made based on DNV OS J-101 and DNV RP B 401 requirements and further refined for the complexity of the foundation structure. The time-dependent modeling approach allowed simulating the evolution of the CP efficiency in the sand filled compartments, Elsyca said.
The five foundations will be installed off the Northumberland coast in the North East of England during the summer of 2017. The foundations will support five optimised MHI Vestas V164-8.0 MW turbines.