What is copper loss in subsea electrical systems?
A subsea cable can have multiple copper conductors that carry electrical current in the form of power or communication signals, and an insulating layer which isolates the conductors from other conductors and electrical earth.
Due to its high conducting/low resistance and other material properties, alongside its availability and cost, copper is a common material found in subsea electronics, especially cables. However, despite its ubiquity, there are disadvantages to using copper in subsea electrical systems where the use of a LIM is a statutory requirement.
If subsea cable insulation is damaged, or suffers degradation through ageing, seawater penetrates the cable and encounters the conducting copper core. Seawater is an electrolyte with sodium and chloride ions in solution.
When the system is active with its normal operating current running through the system, the copper cable immersed in the seawater electrolyte becomes an anode and the steel wire mesh protecting the cable becomes the cathode.