A solar solution

In 2003, SOUTHWEST CORROSION CONTROL was asked to provide external corrosion control for a natural gas pipeline facility in a remote area of West Central Alberta. The estimated current requirement was determined to be 4 amps D.C.

The traditional method would be to install an impressed current cathodic protection rectifier—but there was no commercial power available within a reasonable distance. A second option would be to provide the required current via a Thermo-Electric Generator; these units burn natural gas to heat a thermocouple to generate the D.C. current. However, the natural gas available in the pipeline had a H2S component so was unsuitable as a fuel source. 

Our solution was to design a solar power array to enable a constant flow of cathodic protection current to the pipeline system. The solar panels charged a large battery array during daylight hours and the batteries took over during darkness. The actual performance of this system delivered an average of 4 to 5 amps D.C. even in winter months during shorter daylight hours. The substantial height of the Solar Panel Array was needed due to the close proximity of tall trees. An idea of the size can be determined by looking at the tail-rotor of the helicopter in the bottom right hand side of the photo.