Cathodic protection and corrosion control
for offshore wind turbines and wind farms
Offshore wind turbines suffer very corrosive conditions for which they are often under-protected.
Offshore wind turbines are typically located in environments that are difficult for cathodic protection designers to overcome. Placed in estuaries - commonly in very shallow water - their structures are at serious risk from high flow rates and seabed movement. Typical offshore cathodic-protection designs can fall drastically short under these conditions.
A specialized solution - In 2004-2005, Deepwater was commissioned to put 20 years of experience with the offshore oil and gas industry into designing a cathodic protection system to overcome these problems. The environmentally friendly, buried impressed-current VSE Anode(Vaulted Seawater Envelope) was the result. Designed specifically for shallow-water wind farms, the VSE allows turbine operators to retrofit new cathodic protection to existing turbines. The unit is powered by the turbine itself and provides corrosion protection to all subsea and buried metal components of the structure.
Monopile Interiors are at risk - Many offshore wind turbines have uncoated monopile interiors. In several instances where the seal has leaked, these turbines have filled with water, causing a severe and immediate risk to the integrity of the structure. Luckily, with minor modifications to the structure, sacrificial anodes can be installed inside to protect the uncoated steel. RetroLink anodes can protect this internal area from corrosion without underwater intervention, keeping emergency installation costs as low as possible.
Coatings and general corrosion above water - Wind turbines suffer above-water as well, where cathodic protection is impossible. Corrosion-induced failure of components associated with the dynamics of the turbine could have catastrophic results. Deepwater's risk-based inspection services can greatly reduce the risk of failure. We provide inspection and consulting services for all types of corrosion-prevention problems.
Related technical papers
Offshore Cathodic Protection 101
A brief tutorial about the science of cathodic protection as it relates to offshore structures, complete with diagrams, chemical equations etc.
Offshore Risk-based Corrosion Integrity Management
The management of corrosion and integrity for offshore applications has become more critical as deepwater exploration and production continues. There are many challenges ahead ...
Corrosion control products for wind turbines
VSE Anode™
Protecting the buried steel, the VSE Anode (Vaulted Seawater Envelope ICCP anode) is designed to provide CP in shallow water locations where the anode system must be buried below natural bottom. The unit was first commissioned on an offhsore wind farm in 2004.
RetroLink™
For fast, affordable protection, the RetroLink system is a string of anodes installed topside and then hung to the sea floor. Many turbines have trouble keeping water out, but RetroLinks can be used to protect either the internal or external steel of a wind turbine monopile.
SmartMat™
A sacrificial anode system, the SmartMat is a standard concrete stabilization mattress with aluminum or zinc sacrificial anodes cast inside each segment. The compliant nature of the mat combined with its weight make it a good choice for unstable conditions too harsh for the VSE.
CP Monitoring
To monitor the protection, instruments like the Dr-2 CD, a reference electrode cell can be welded to new construction or retrofitted with a RetroClamp to existing structures. These instruments can help monitor potentials and polarization of the structure.