Cathelco have applied their experience of corrosion protection in the marine environment to offshore wide turbine foundations.
Impressed current cathodic protection (ICCP) systems have many advantages in comparison with the more traditional types of sacrificial anode systems. In addition to the being more economical to install, ICCP systems can be managed from a shore base, providing an easily verifiable way of knowing that they are giving reliable corrosion protection.
Lower installation costs
ICCP equipment and installation costs are significantly lower than that of sacrificial anodes. Because the ICCP equipment is much lighter than sacrificial anodes it can be positioned manually avoiding the use of cranes. Furthermore, the fixing points require much less time to install than those for sacrificial anodes.
Manageable from on-shore
At any time the performance of the system can be checked and controlled from an on-shore control room. It is also easy to monitor the system using a personal computer. If the environment below the waterline changes the ICCP system can be immediately adjusted to take account of this. Secondly, a record can be kept of the performance of the system demonstrating the integrity of the foundations. This avoids the time and expense of carrying out offshore surveys.
Sea bed penetration
ICCP systems have a much higher driving voltage than sacrificial anodes enabling the current to reach a depth of up to 5 metres below the sea bed (mudline). This extends corrosion protection to the buried foundations of the structure and combats microbiological influenced corrosion (MIC).
Lower weight/drag than sacrificial anodes
In a typical application 30 – 60 tonnes of sacrificial anodes and their mountings are replaced with just 1 tonne of ICCP equipment. Another important factor is that Cathelco’s surface mounted anodes present significantly less drag than the higher number of offset sacrificial anodes.
Lower maintenance costs
All of Cathelco’s offshore wind turbine anodes are ROV diver changeable saving time, effort and money when it comes to maintenance. The design life of the anodes is up to 30 years.