Til innholdet

Sacrificial anodes for wind turbine foundations

Offshore wind turbines are typically located in shallow water with risk from high flow rates and seabed movement. Commonly applied cathodic protection designs can fall short under these conditions.

Sacrificial anode design

Anodes can be customised to any design or compostion to suit most application and requirements. See the full product range of sacrificial anodes.

Below illustrations show the most common anodes models applied for corrosion protection of external submerged areas of wind turbine foundations.

Various sacrificial anode designs for offshore application

Anywhere steel is immersed in water, anodes will be found.

Protection of external submerged zones

External surfaces of the submerged zone of the foundation requires cathodic protection, either by impressed current cathodic protection or sacrificial anodes. The latter have historically been the most commonly applied method, however ICCP for external corrosion protection of turbine foundations are being applied in an increasing number of projects.

Offshore wind turbine tripod design
ICCP or sacrificial anodes should be applied for corrosion protection below the mean water level.

Cathodic protection for external, submerged surfaces of wind turbines are individually designed for each windfarm or foundation. The design considerations would usually include environmental parameters, detrimental effects, fastening devices, coating breakdown (coating cathegory) and anode life time requirements.

The design life time of anodes is specified by the operator, and covers the period from installation to the end of wind turbine operation. It is normal practice to apply the same anode design life as for the wind turbine foundation.

You may want to read more about design of corrosion protection for wind turbine foundations here.

Internal corrosion protection

Corrrosion protection design internally in monopiles has to consider several issues, including the weight and manageability of the anodes, anode mounting options and hydrogen evolution in sealed environment.

Cathodic protection by sacrificial anodes can be considered a viable option for protecting monopile foundations inernally against corrosion. A common approach is to apply suspended galvanic anodes that are cast directly on a heavy-duty wire rope.

Anodes cast directly on a heavy-duty wire rope
Anodes cast directly on a heavy-duty wire rope

The anode string is attached mechanically and electrically to the monopile above the water line, allowing it to hang in the seawater to provide cathodic protection to the monopile interior areas.

See the full range of sacrificial anodes for wind turbine foundations.