Solar Powered Cathodic Protection Using Residual Potential

Solar panels are a viable economical source of power for cathodic protection installations where grid power is not readily available. First those installations where alternative power sources are feasible are discussed. Then solar panel operation is investigated. This includes an overview of the semiconductor construction of the solar cells as well as the effect of incident light levels on the power output. A description of cathodic protection fundamentals outlines a typical configuration including the need for backup power. Because of the hysteresis effect of direct current on the well casing, a method of protecting the well without using batteries for the backup is demonstrated.