5. Cathodic Protection

5.12 Comparison of Galvanic Anode and Impressed Current Systems

A comparison of galvanic anode and impressed current cathodic protection system is given below:


Advantages Disadvantages

Galvanic Anode Systems

Requires no external power source Fixed driving voltage
Easy installation Limited current output
Less expensive Requires more frequent replacement of anodes
Ease of maintenance -

Impressed Current Systems

Uses external power source. Rectifiers provide the current needed for cathodic protection. Cannot be installed in areas without power.
Current may be varied Installation of the impressed current system is complex.
Suits any changes in the system It is more expensive than sacrificial system.
Designed for longer life and no restrictions on the length of structure to be protected. Frequent maintenance is needed.